Lymph Node Research Articles

6504 Cerebellar Metastases from Papillary Thyroid Cancer; An Unusual Presentation

Abstract Disclosure: L.E. Chozet: None. A. Gilbert: None. M.A. Escobar Vasco: None. Background: Differentiated papillary thyroid cancer is known to have a very favorable prognosis. Brain metastases arising from papillary thyroid carcinoma are a very rare complication seen in approximately 1% of all cases of differentiated thyroid cancer with cerebellar metastases being even more uncommon. We present a case of a patient presenting with ataxia as the initial and only symptom of papillary thyroid carcinoma, found to have cerebellar metastases. Clinical Case: A 68-year-old man presented with ataxia for 1 week prior to arrival to hospital. CT head revealed hyperdense lesions in the right frontal lobe and left posterior cerebellar hemisphere. The patient underwent resection of left cerebellar mass with final pathology consistent with metastatic papillary thyroid carcinoma. Tumor cells were positive for TTF-1, thyroglobulin, CAM5.2, CK7, and PAX8, and negative for CK5/6, CK20, inhibin, and Napsin A. Ultrasound of the thyroid revealed multinodular goiter with dominant left thyroid lobe nodule 4 cm in size. PET CT showed left Thyroid mass with direct extension to adjacent lymph nodes, right anterior rib mass, left adrenal metastasis and right frontal lobe and left cerebellar metastasis. He received stereotactic radiosurgery with 5 out of 5 treatments completed. He subsequently underwent total thyroidectomy with left modified radical neck dissection, with pathology showing pT3bN1bM1. Next Generation Sequence positive for V600E, RADS1CR193, TERT PROMOTER -124C>T. After multidisciplinary team discussion, it was determined that the best course of action was to refer the patient to MD Anderson for evaluation, candidacy for prospective therapeutic clinical trials. Conclusion: This case demonstrates how differentiated papillary thyroid cancer, despite its favorable prognosis, can still prove to be a dangerous disease especially if undiagnosed for several years. This case also illustrates how papillary thyroid carcinoma can remain clinically silent for years and first present with atypical symptoms consistent with advanced metastases. Presentation: 6/2/2024

12325 Adrenocortical Carcinoma Masquerading As Pheochromocytoma In A Patient With Congenital Adrenal Hyperplasia

Abstract Disclosure: E.M. Niedzialkowska: None. A.A. Banka: None. Introduction: The development of adrenocortical carcinoma (ACC) in patients with congenital adrenal hyperplasia (CAH) is rare. The patients with CAH are at increased risk of adrenal tumors which is attributed to ACTH stimulation of adrenal gland if the disease is not appropriately treated. ACC cases mistaken for pheochromocytomas have been reported in the literature and are attributed to the variety of immunohistochemical markers expressed by the tumors. Case description:59 y.o female with salt-wasting CAH diagnosed at the age of 2 (21-hydroxylase deficiency) on hydrocortisone supplementation reported to the hospital due to episodes of sweating, tachycardia and hypertension. Work up revealed mildly elevated plasma normetanephrine 1 nmol/l (N <0.9), urine normetanephrine 1762 mcg (N<899), VMA 11.2 mcg/24hr (N 3.3-7.2). MRI of the abdomen revealed 2 left adrenal masses of 3.7 and 2.4 cm, right adrenal gland hyperplasia and low T1 and T2 enhancement. I-123 MIBG revealed increased activity and thickness of the right adrenal gland and no significant uptake on the left with nodular masses. The patient underwent left adrenalectomy with pathological report consistent with pheochromocytoma due to positive chromogranin and synaptophysin staining and moderate Ki activity. A year later follow up imaging showed an enhancing mass up to 7 cm at the suprarenal fossa invading the left kidney that was positive for nodular adrenocortical hyperplasia per pathology report. The patient continued to have elevated 17-OH- progesterone (2740 ng/l, N <51) despite compliance with her steroid therapy and suppressed ACTH. She underwent mass resection along with nephrectomy, splenectomy, partial colectomy and partial pancreatectomy. Pathology report was positive for adrenocortical carcinoma (positive chromogranin, synaptophysin, CAM 5.2, polycystic cytokeratin, Ki positive in greater than 10% of the tumor cells) with renal and regional lymph node invasion and colonic metastases. The patient was started on mitotane therapy but a year later PET scan was positive for liver and omental metastases and was subsequently started on carboplatin/etoposide followed by streptozocin/adriamycin with initial good response, however repeat PET a year afterwards showed progression of the liver lesions, metastases to omentum and metastatic lesion to calvarium and the patient expired soon afterwards. Discussion: CAH predisposes patients to adrenal tumors which is attributed to increased ACTH stimulation of the adrenal gland but ACC in this population is extremely rare. In very rare cases ACC can present clinically as pheochromocytoma with elevated catecholamine levels and positive synaptophysin and chromogranin staining which poses a clinical challenge. Both CAH and ACC can lead to increased androgen levels and ACTH levels can help to differentiate the origin of the hyperandrogenemia. Presentation: 6/2/2024

Evaluation of the da Vinci single-port system in colorectal cancer surgery: a scoping review.

Minimally invasive surgery for the treatment of colon and rectal cancer has gained popularity due to its association with reduced postoperative pain, shorter hospital stays, and quicker recovery. The Da Vinci Single-Port (SP) System combines single-port laparoscopy with robotic assistance. This scoping review aims to evaluate the safety and short-term postoperative outcomes of utilizing the Da Vinci SP platform in colorectal cancer surgery. A scoping review was conducted adhering to the PRISMA-ScR guidelines. Data were collected from PubMed, Embase, and the Web of Science Library as of December 22, 2023. Studies were screened and selected based on predefined criteria, focusing on the application of the SP robotic system in colorectal procedures. Data extraction included demographics, surgical details, intraoperative and postoperative outcomes. A narrative summary of the results was provided due to the heterogeneity in study designs. From an initial 2312 articles, 22 studies were selected for analysis, encompassing 465 patients undergoing robotic SP colorectal surgeries. Of these, 384 (82.6%) had a cancer diagnosis. The median age was 65years, with approximately 60% being male. The median operative time was 225min, with docking times averaging 12-20min. Conversion to multi-port laparoscopy occurred in 4.2% of cases, with no conversions to open surgery. Mean intraoperative blood loss ranged from 50 to 150ml. The mean number of lymph nodes retrieved ranged from 15 to 28. A diverting ileostomy was constructed in 20.3% of patients. Median times to flatus and soft diet were 2.5 and 3days, respectively, with hospital stays ranging from 3 to 11days. Perioperative complications occurred in 15.1% of patients, including wound infections (5.1%), anastomotic leakage (3.7%), and postoperative ileus (2.8%). Negative margin status (R0 resection) was achieved in 95% of cases. The Da Vinci SP robotic platform demonstrates promising safety and effectiveness in colorectal cancer surgery. It achieves high rates of successful oncological resection, adequate lymph node retrieval, and minimal intraoperative blood loss. Postoperative outcomes indicate quicker recovery times and manageable complication rates. However, longer follow-up studies are necessary to fully assess recurrence rates and long-term survival benefits associated with this innovative surgical approach.

Prognostic Impact of HER2 Low Status in Male Breast Cancer: Prospective Cohort Analysis

Background: Male breast cancer (MBC) is a rare disease, and the potential influence of low expression of human epidermal growth factor receptor 2 (HER2 low) remains unexplored. Methods: In this prospective cohort study, we evaluated 870 patients treated for MBC between May 2009 and June 2023 to assess HER2 low status and its prognostic implications. Results: With a median follow-up of 43 months (range 1–175 months), 659 eligible patients were categorized into three groups based on HER2 status: 501 (76%) HER2 low, 81 (12.3%) HER2 zero, and 77 (11.7%) HER2 positive. HER2 positivity correlated with younger age, higher proliferation index, non-specific type histology, lymphovascular invasion (LVSI), and low differentiation grade. Notably, all these parameters were equally distributed between the HER2 zero and HER2 low groups. Additionally, HER2 positivity was significantly associated with increased occurrences of regional and distant lymph nodes and pulmonary metastases. However, no statistically significant difference was observed between HER2 zero and HER2 low. Disease-free and overall survival showed no significant disparities between the groups. Conclusions: Our findings suggest that HER2 low status is frequently detected in MBC. Despite this, HER2 low did not correlate with clinical and pathological parameters, nor did it impact patients’ survival.

12243 The Case of a Metastatic Papillary Thyroid Cancer Presenting as an Unresectable Pelvic Mass

Abstract Disclosure: M. Tucktuck: None. Y. El Soufi: None. O.G. Adeniran: None. A.A. Gliwa: None. Background: Papillary thyroid cancer (PTC) represents around 85% of all thyroid cancers, of which 2-10% of patients will present with metastasis distant to the neck. The frequency of bone metastasis in PTC occurs in only 1-4% of patients. Studies have shown that distant and multi-organ metastasis is associated with higher mortality rates. Clinical case: A 69-year-old woman with diabetes mellitus, cerebrovascular accident, and right lower extremity deep venous thrombosis, presented with right foot and hip pain for 1 week after a mechanical fall. She had a 50 pound weight loss over a year without personal or family history of thyroid cancer or disease or radiation exposure. A soft and nontender mass in the right lower abdomen was noted during a physical exam. Imaging revealed a large heterogeneous lesion (16.3 x 13.3 x 15.5 cm) in the right bony pelvis with internal necrosis, destructing the right iliac bone, and extending into the right sacrum, acetabulum, and musculature, with mass effect on the surrounding vasculature, and enlarged lymph nodes suspicious for metastasis. Thyroid imaging showed a hypervascular hyperechoic 1.3 cm nodule within the right thyroid gland and a large 2 cm left thyroid nodule with scattered microcalcifications. Thyroid function tests were within normal limits. The patient underwent an initial ultrasound guided biopsy of the pelvic mass with indiscriminate results, and later a laparoscopic excisional biopsy of the pelvic mass showed neoplastic papillary proliferation with typical nuclear features, without necrosis or associated ovarian tissue. The immuno-histopathological profile was positive for PAX-8, TTF-1, thyroglobulin, and CK7, and the Ki-67 proliferation index was ∼20-30%. The patient was diagnosed with papillary thyroid cancer with metastasis to the pelvic bone, and was classified as stage IV, cT1bN0M1. As the pelvic mass was inoperable, the patient completed total thyroidectomy and was started on hormone replacement therapy. Subsequent thyroid pathology report was negative for papillary carcinoma. Further review of imaging did not show ectopic thyroid tissue in the neck or an ovarian pathology. Before the patient’s next visit to evaluate for struma ovarii, she passed away. Conclusion: Thyroid cancer is usually treated through thyroidectomy or lobectomy, with radioiodine (RAI) therapy as an effective treatment for differentiated cancers. Our patient, who presented with extremity pain revealing a distant metastasis, completed thyroidectomy with plans to undergo RAI therapy. Our case highlighted the importance of recognizing musculoskeletal presentations as an initial and possibly only finding of a distant metastasis. It also emphasized the utility of multidisciplinary collaboration in detecting and recognizing PTC as a primary thyroid cancer, as early management can reduce mortality and lead to more favorable outcomes. Presentation: 6/2/2024

7553 Thyroid Paraganglioma: A Complex Tale of the Familiar Thyroid Nodule

Abstract Disclosure: V. Moorthy: None. A. Kondapally: None. L.E. Kimball-Ravari: None. Background: Thyroid paragangliomas are rare and often misdiagnosed on fine-needle aspiration (FNA). Clinical Case & Discussion: A 58-year-old female presented with an asymptomatic “cold” thyroid nodule. Ultrasound demonstrated a 2 cm hypoechoic nodule in the isthmus. FNA yielded a follicular lesion of undetermined significance, and genomic sequencing estimated a 50% risk of malignancy prompting the patient to opt for total thyroidectomy. Histopathology and immunohistochemistry (IHC) confirmed the diagnosis of benign paraganglioma (PGL). SDH-B (succinate dehydrogenase subunit B) was notably absent on IHC. Past medical history is significant for hysterectomy for uterine fibroids and obesity, along with a confirmed family history of Hereditary Leiomyomatosis with Renal Cell Cancer (HLRCC). The patient and several family members tested positive for a pathogenic variant of fumarate hydratase (FH) gene implicated in HLRCC and undergo annual MRIs for cancer surveillance. The loss of SDH-B suggests underlying mutation. Germline SDH mutations occur in 20% of patients with pheochromocytoma and PGLs, predisposing to hereditary syndromes. PGLs are catecholamine-secreting neuroendocrine tumors with carotid body and jugular PGLs accounting for 80% of head and neck PGLs (HNPGLs). Thyroid PGLs originate from the inferior laryngeal paraganglia. They are very rare, often non-secretory, and commonly present as asymptomatic solitary nodules. For these reasons, FNA, while contraindicated, is frequently performed. If FNA is considered, pre-procedural alpha-adrenergic blockade is recommended, although catecholamine secretion triggered by FNA is uncommon. Thyroid PGLs are misdiagnosed on FNA as other thyroid neoplasms. Awareness of the more unique cytopathology of thyroid PGLs and a comprehensive IHC can aid in accurate diagnosis. Interestingly, SDH (complex 2) and FH are closely linked enzymes in the Krebs cycle. Emerging evidence correlates germline FH mutations and hereditary pheochromocytoma-paraganglioma. PGLs are less commonly associated with MEN 2A and 2B, NF type 1, VHL, and Carney-Stratakis syndrome and Carney triad. Therefore, additional testing for SDH, RET, VHL and MAX genes was recommended in this case. Total thyroidectomy or lobectomy with or without elective lymph node dissection remains the treatment of choice. Annual 24-hour urine and plasma metanephrine testing will help screen for potential recurrence. Use of GLP1 agonists for weight loss in this patient warrants further genetic and safety evaluation. Clinical Lesson/Conclusion: Often misdiagnosed on FNA, thyroid paragangliomas are rare, with multiple genetic predispositions. FNA is contraindicated and if considered, must be performed after alpha-blockade. Germline SDH mutations are implicated in PGLs and increasing evidence links FH mutations to hereditary PGLs. Presentation: 6/3/2024

Inhibiting SNX10 induces autophagy to suppress invasion and EMT and inhibits the PI3K/AKT pathway in cervical cancer.

Cervical cancer (CC) is a prevalent malignancy among women with high morbidity and poor prognosis. Sorting nexin 10 (SNX10) is a newly recognized cancer regulatory factor, while its action on CC progression remains elusive. Hence, this study studied the effect of SNX10 on CC development and investigated the mechanism. The SNX10 level in CC and the overall survival of CC cases with different SNX10 expressions were determined by bioinformatics analysis in GEPIA. The SNX10 expression in tumor tissues and clinical significance were studied in 64 CC cases. The overall survival was assessed using Kaplan-Meier analysis. The formation of LC3 was evaluated using immunofluorescence. Cell invasion was measured using the Transwell assay. Epithelial-to-mesenchymal transition (EMT) was determined by observing cell morphology and assessing EMT marker levels. A xenograft tumor was constructed to evaluate tumor growth. SNX10 was elevated in CC tissues and cells, and the CC cases with high SNX10 levels exhibited poor overall survival. Besides, SNX10 correlated with the FIGO stage, lymph node invasion, and stromal invasion of CC. SNX10 silencing induced CC cell autophagy and suppressed CC cell invasion and EMT. Meanwhile, silenced SNX10 could suppress invasion and EMT via inducing autophagy. Furthermore, SNX10 inhibition suppressed the PI3K/AKT pathway. Moreover, silenced SNX10 restrained the tumor growth, autophagy, and EMT of CC in vivo. SNX10 was enhanced in CC and correlated with poor prognosis. Silenced SNX10 induced autophagy to suppress invasion and EMT and inhibited the PI3K/AKT pathway in CC, making SNX10 a valuable molecule for CC therapy.

8760 Does an Increased Size of Thyroid Nodules Correlate with a Higher Probability of Intermediate or High-Risk Histopathological Features for Recurrence?

Abstract Disclosure: R. Pishdad: None. N. Yousefzadeh: None. E. Gough: None. L. Rooper: None. J.S. Mammen: None. Does an increased size of thyroid nodules correlate with a higher probability of intermediate or high-risk histopathological features for recurrence? Background: The existing practice guidelines recommend total thyroidectomy for solitary nodules exceeding 4 cm regardless of other pre-operative findings. We hypothesize that through comprehensive pre-operative assessments, particularly including a thorough neck ultrasound, even nodules exceeding 4 cm that would otherwise meet ATA criteria for lobectomy (i.e., lacking extrathyroidal extension and suspicious lymphadenopathy) will not exhibit occult high-risk features at a higher rate compared to nodules measuring 1-4 cm. Consequently, these larger nodules would not necessitate a higher rate of completion thyroidectomy. Methods: Solitary thyroid nodules with a largest dimension ≥ 1 cm and operated on at a single institution between 2005 to 2023 were assessed to identify those that would have met ATA criteria for lobectomy. Surgical pathology reports were reviewed to perform risk stratification following ATA guidelines. Preoperative cytopathology, ultrasound characteristics, and patient demographics were considered as covariables. Statistical analyses were performed with R programming language. Simple logistic regression and multivariable logistic regression were performed to analyze the finding of occult intermediate or high-risk features based on size. Results: We identified 461 cases of solitary nodules without extrathyroidal extension or lymph node involvement (406 nodules 1-4 cm; 60 nodules ≥ 4 cm). Patients with larger nodules were more likely to be male than those with smaller nodules (52% versus 26%; P value <0.001). Interestingly, while the majority of smaller nodules meeting criteria for lobectomy were suspicious or malignant by cytopathology (Bethesda 5 and 6), only 20% of larger nodules that met criteria were malignant, with 68% either Bethesda 3 or 4 (p<0.001). There were no statistically significant associations between size or other variables such as age, race, sex, or positive family history and post-operatively assessed high/intermediate risk for recurrence. Conclusion: In this analysis of solitary nodules with larger sizes, the dimension itself did not emerge as a risk factor for occult intermediate or high-risk surgical pathology. Thus, the rates of completion thyroidectomy in appropriately screened patients would be acceptable even in patients with nodules greater than 4 cm. The majority of larger nodules that fulfill preoperative ATA criteria for lobectomy were assessed to be ACUS or a follicular neoplasm on pre-operative fine-needle aspiration. This suggests that the higher risk of more aggressive disease previously reported with larger nodules can be detected during preoperative assessment, emphasizing the essential role of neck US in the comprehensive evaluation of larger nodules. Presentation: 6/2/2024

7235 Papillary Thyroid Carcinoma in a Hyperfunctioning Thyroid Nodule

Abstract Disclosure: J. Yang: None. P.V. Nadkarni: None. Background: The prevalence of malignancy in a hyperfunctioning or hot thyroid nodule is considered to be low. According to the 2015 American Thyroid Association Guidelines, no cytologic evaluation is routinely recommended for hyperfunctioning nodules since they are rarely associated with malignancy (1). We present a case of a 71-year-old female with a hot nodule containing papillary thyroid cancer. Clinical Case: A 71-year-old female with Type 1 diabetes mellitus and coronary artery disease on dual antiplatelet therapy was found to have a 1.5 cm firm, non-tender right-sided thyroid nodule on a routine physical exam. Laboratory tests demonstrated low TSH <0.01 (normal 0.36 - 3.74 m[IU]/L) and FT4 level elevated at 1.62 (normal 0.76 -1.46 ng/dL). She noticed palpitations and started on low dose Methimazole. Thyroid ultrasound results showed a 2.1 x 2.0 x 2.0 cm right inferior lobe thyroid nodule. This thyroid nodule appeared mixed cystic and solid, hypoechoic, not taller than wide, with ill-defined margins and peripheral calcifications (ACR TI-RADS risk category: TR4). Nuclear medicine thyroid uptake scan demonstrated focally increased activity in the right lower pole corresponding with her right inferior thyroid nodule seen on ultrasound. Remainder of the gland appeared suppressed. She was recommended for ultrasound-guided fine needle aspiration biopsy of her right inferior thyroid nodule, given concerning characteristics on ultrasound findings despite results consistent with a hot nodule. Timing of her antiplatelet therapy was coordinated with her cardiologist, and her biopsy procedure scheduled after she stopped dual antiplatelet therapy. Her FNA results showed clusters of follicular cells with nuclear and architectural atypia, suspicious for papillary thyroid carcinoma. She underwent right thyroid lobectomy. Surgical pathology revealed 2 foci of papillary thyroid carcinoma, follicular variant (2.0 cm, 0.1 cm) and confined to the thyroid. All regional lymph nodes were negative for tumor. Methimazole was discontinued post-operatively, and she started Levothyroxine suppression therapy. Discussion: We present a rare association of papillary thyroid carcinoma presenting as a hot thyroid nodule. Though uncommon, detection of a hyperfunctioning thyroid nodule does not exclude the possibility of thyroid carcinoma and warrants careful evaluation. Clinicians should retain a high index of suspicion particularly when ultrasonography demonstrates findings suspicious for malignancy and consider additional evaluation with fine needle aspiration. Reference: (1) Haugen BR, Alexander EK, Bible KC et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016 Jan;26(1):1-133. Presentation: 6/2/2024

ASO Author Reflections: Optimization of Extended Pelvic Lymph Node Dissection Side for Prostate Cancer.

ASO Author Reflections: Optimization of Extended Pelvic Lymph Node Dissection Side for Prostate Cancer.

12238 A Case Of Drug-induced Vasculitis

Abstract Disclosure: C. Javier: None. M.H. Horani: None. Title: A Case of Drug-Induced VasculitisChristian Javier, DOMohamad Horani, MD Introduction: Graves’ disease is commonly managed with thionamides. These have rare but serious complications of drug-induced lupus-like syndrome and vasculitis. In patients who present with rheumatologic and inflammatory findings, it is important to consider the possibility of these complications . Case Presentation: We present a 30-year-old female with Graves disease, asthma, and hypertension with concerns for cough, body aches, fatigue, bilateral flank pain, erythema, itching and burning of the hands, in the setting of recent spontaneous miscarriage. She was diagnosed with Graves’ nearly 2 years ago and was started on methimazole, but discontinued due to adverse effects of the medication. She was then started on PTU. The patient had a seizure, and head CT revealed a left-sided 4 cm brain mass in the left frontal lobe. The patient was admitted to the ICU, intubated, and started on IV Decadron. Further imaging showed multiple enlarged lymph nodes in the axilla, mediastinum, and hilum. Her brain mass was biopsied showing acute inflammation with early acute necrosis and multifocal fibrinous vascular necrosis, which has been reported in ANCA vasculitis. She had undetectable TSH (0.35-5.0) and free T4 of 1.54 (4.87-11.72). She was also found to have proteinuria and AKI. At this point, PTU-induced vasculitis and drug-induced lupus were suspected and PTU was discontinued. She was found to have low complement levels (C3 40, C4 6.1), elevated p-ANCA (>1:1280), ANA (1:640), anti-histone IgG (2.3) dsDNA (1:160), SSB La antibodies (70), anti-Smith antibodies (319), anti-RNP antibodies (146). Renal biopsy is pending. After discontinuation of PTU and administration of IV steroids, her symptoms largely resolved and she was extubated and stable for discharge. Conclusion: In patients being treated for Graves’ disease with PTU, there are rare but life-threatening complications associated with this medication including lupus-like state or vasculitis with elevated ANCA antibodies. Common presenting symptoms of drug-induced vasculitis include fever, joint pains, myalgias, skin lesions, glomerulonephritis, cerebral angiitis, and pulmonary hemorrhage. The onset of vasculitis can occur at any time after starting medication, with one study showing an average onset of 36 months after initiation of therapy. Other case reports have demonstrated positive serologies for ANA and anti DS-DNA antibodies in those with PTU-induced lupus. Drug induced lupus can also occur in patients taking PTU, with kidney and CNS involvement being more uncommon. In those with p-ANCA associated vasculitis secondary to PTU, anti-GBM, antiphospholipid, and antinuclear antibodies can also be present. Presentation: 6/1/2024

7550 Case Report On Concurrent Metastases To The Pituitary And Adrenal From A Primary Breast Cancer

Abstract Disclosure: M.V. David-santos: None. M.C. Isidro: None. Background: Metastatic Cancer to the pituitary gland is a rare condition accounting for 0.5% of all pituitary tumors. It rarely manifests clinically and is often found incidentally. Endocrine dysfunction usually arise, with 38.4% of cases presenting with Diabetes Insipidus, while 37.7% as Panhypopituitarism. On the other hand, prevalence of adrenal metastases is at 0.5 to 3.8% with 43% occurring bilaterally. Primary adrenal insufficiency occurs at 12.4% among those with bilateral metastases. Case: A 32-year old Chinese woman was diagnosed with Stage 4 breast adenocarcinoma ER PR Her2 Neu positive with metastases to the axillary lymph nodes, bone and right adrenal in July 2021. She underwent chemotherapy with Paclitaxel and Trastuzumab then radical mastectomy of the left breast in April 2022.5 months post op, PET scan was done which showed a 11 x 18 x 21 mm pituitary mass. In light of the primary malignancy, lesion was considered a metastatic focus. At that time, patient did not exhibit any neurologic symptoms such as blurring of vision or headaches. No polyuria, polydipsia, nocturia, easy fatigability, nausea or vomiting. Physical examination findings were normal. A hormonal panel showed the following: elevated Prolactin at 150 ng/ml (NV 3-20), normal plasma ACTH IRMA 10 pg/ml (NV < 50 pg/ml), low 8AM plasma cortisol at 1.55 ug/dL (Ref 5- 25 ug/dL), TSH was low at 0.15iIU/ml (0.27-3.75) while FT4 was normal at 0.87 ng/dl (NV 0.68 - 2.56).ACTH stimulation showed low cortisol at the 30th minute and 1st hour post ACTH infusion. Serum sodium and urine Osmolality were both normal. The hyperprolactinemia was attributed to Stalk effect, while the decreased cortisol was considered as central adrenal insufficiency. She was then started on Prednisone 5mg tab daily. Repeat TSH and FT4 5 months after showed normal TSH at 1.209, low FT4 at 5.97 pmol/L (NV 9.01-19.05). She was started on Levothyroxine 50mcg daily for the central hypothyroidism.Repeat Cranial MRI 4 months post diagnosis of the pituitary mass showed increased in its size. An endoscopic transsphenoidal resection and biopsy of the pituitary mass showed metastatic carcinoma of the pituitary gland. Staining of the sellar tumor were compatible with a metastatic carcinoma of breast origin. Intensity-modulated radiation therapy (IMRT) at 400 gray was done for 5 fractions and Trastuzumab was continued. Cranial MRI done 6 months post IMRT showed decreasing size of the pituitary mass to its latest size of 6 x 9 x 13 mm as of November 2023. Latest Whole abdominal CT scan of the adrenals showed clearing of the right adrenal Nodule. Conclusion: Breast cancer may also metastasize to endocrine organs causing hormonal dysfunction. Although curative treatment is no longer the goal for Metastatic breast cancer, prolongation of the quality of life is an important aspect to consider. Hormonal work up, surveillance and hormonal replacement can help in attaining this goal. Presentation: 6/3/2024

8581 Unusual Case of Multifactorial Hyperthyroidism

Abstract Disclosure: D.D. Bagar: None. E. Meyers: None. M. Correia: None. Background: Nivolumab is an immune checkpoint inhibitor that is used to treat specific types of cancer, including melanoma, by increasing the ability of the immune system to detect cancer through activating cytotoxic T-cells. The side effects of immune checkpoint inhibitors are mainly through the overactivation of the immune system that can affect many organs with autoimmune diseases, including endocrine glands, which could be severe and irreversible, like hypothyroidism or immune thyroiditis. The uniqueness of this case is the presence of multifactorial causes of hyperthyroidism; in addition, it is one of the few cases of immune checkpoint inhibitor induced positive TSI thyroiditis.Clinical Case: An 82-year-old male with a known history of atrial fibrillation on amiodarone presented to his dermatologist with a left forearm lesion. A shave biopsy showed melanoma, and he underwent wide local excision with negative sentinel lymph node biopsy. However, he had significant melanoma in situ present within 5 mm of the margin and was deemed not a candidate for further excision. Tumor board recommended close surveillance. He then received two cycles of pembrolizumab for one year, followed by nivolumab. During his treatment course, he had CT scans with iodinated contrast every 8-12 weeks for the clinical trial. At his clinic visit, routine thyroid function tests were significant for hyperthyroidism with a TSH <0.01 and free T4 of 6.07 (0.8-1.8). He was asymptomatic except for unintentional weight loss. He denied using any biotin supplements. His labs also showed positive thyroid stimulating immunoglobulin (TSI) of 1.10 (<=0.54 IU/L). A thyroid US with doppler showed two nodules less than 1.1 cm and no increased vascularity. Amiodarone was discontinued, and prednisone and methimazole were started. His free T4 has since normalized and both prednisone and methimazole are being tapered down. Conclusion: This case is a multifactorial cause of hyperthyroidism. He had been using amiodarone for atrial fibrillation, had multiple imaging studies with iodinated contrast, and was on immune checkpoint inhibitor therapy with a positive TSI. The uniqueness of this case is not only that combined factors can affect thyroid function but also that he developed a positive TSI, which indicates either Graves’ disease or immune-induced thyroiditis by nivolumab, which has been reported only in a few cases. Presentation: 6/3/2024

7466 The Effects Of Various Forms Of Diabetes On Features Of Tumor Aggressiveness In Thyroid Cancer

Abstract Disclosure: R.D. Paparodis: None. E. Karvounis: None. A. Kapezanou: None. S. Livadas: None. G. Simeakis: None. D.P. Askitis: None. I. Androulakis: None. N.G. Angelopoulos: None. D. Zianni: None. A. Rizoulis: None. A. Boniakos: None. I. Perogamvros: None. D. Bantouna: None. J.C. Jaume: None. Introduction: Diabetes has been linked to increased risk for several cancers and aggressiveness of tumor behavior. A link between thyroid cancer and diabetes appears controversial in the literature as of yet. We designed the present study to assess whether autoimmune (type 1 + LADA = DM1) or type 2 diabetes (DM2) are associated with more aggressive thyroid cancers compared to those found in non-diabetic (non-DM) individuals. Methods: We retrospectively reviewed data from patients undergoing thyroid surgery in 10 Endocrinology and Endocrine Surgery Clinics throughout Greece over 2 years. We collected data on history and type of diabetes, pre-existing to the thyroid surgery, its treatments and duration, the preoperative thyroid function tests and the surgical pathology findings. We compared the incidence of various histological types of thyroid cancer and the features of tumor aggressiveness between patients with diabetes and those with normal glucose homeostasis (non-DM) (DM1 vs. DM2 vs. non-DM). Results: Overall, n=808 subjects with thyroid cancer were included: n=571 were females (70.7%), age 47.3 ± 14.3 years, BMI 27.0 ± 5.0 Kg/m2, mean TSH 1.99 ± 2.21 mIU/L; n= 692 were non-DM, n=10 had DM1 and n=107 had DM2. Histology revealed n=5 poorly differentiated / anaplastic, n=13 medullary, n=12 Hürthle cell, n=17 follicular and n=773 papillary thyroid cancers (PTC); n=20 (2.5%) with aggressive histological subtypes of PTC, n=5 (0.6%) with distant metastases (MET), n=199 (24.6%) with extrathyroidal extension (ETE), n=419 (51.9%) with capsular invasion (CI), n=225 (27.8%) with lymph nodes involvement (LNi) and n=23 with cancer recurrence (CR) (2.8%). The incidence of aggressive histological types, CR, MET or number of I-131 treatments were not different between groups (p>0.05). ETE, CI and LNi were significantly more common in non-DM compared to both diabetes groups, while gross ETE was more common in DM2 over DM1 and non-DM (p<0.001). Conclusions: More DM1 than DM2 seem to confer a protective effect on several features of cancer aggressiveness in affected individuals. On the other hand, more DM2 than DM1 seems to significantly promote gross ETE. No effect was observed pertaining to the risk for more aggressive tumors or histological subtypes of PTC. Although aggressiveness of thyroid cancer seems controlled in DM1 and to a lesser degree in DM2 the complex interplay between autoimmunity, hyperglycemia and thyroid cancer biology requires larger sample size to better determine causative effects. Presentation: 6/2/2024

8078 TERT Positive Thyroid Nodule in the Setting of Metastatic Melanoma

Abstract Disclosure: E. Langnas: None. S. Chao: None. K.M. Gomes: None. A. Bhan: None. Metastatic disease to the thyroid gland is uncommon with a reported incidence of up to 4% in post-surgical specimens. Lung cancer is the most common primary tumor site in autopsy series. Clinically, renal cell carcinoma is the most common primary tumor site. Metastatic melanoma to the thyroid gland is clinically rare, however, in autopsy series, it has been reported with incidence of up to 39%. A 61-year-old man presented to the endocrinology clinic for an incidentally detected thyroid nodule. He had recently presented with a chronic cough, prompting a chest x-ray that revealed pulmonary nodules. Subsequent computed tomography (CT) showed numerous bilateral lung nodules measuring up to 2.5 cm and an incidental thyroid nodule. Ultrasound of the thyroid identified a 2.7 cm mixed cystic-solid right thyroid nodule. No risk factors for thyroid cancer were identified. His TSH was 3.51uIU (0.45 - 5.33 uIU/mL). The thyroid nodule was biopsied, and pathology revealed atypical spindle cells with irregular nuclear membranes and scattered histiocytes. A further review with cytopathology suggested non-thyroidal origin of the cells. Molecular testing with AFIRMA reported a telomerase reverse transcriptase (TERT) promoter mutation at C228T. The sequencing was negative for TERT C250T, BRAF, RET, PETC1, PTC3 and MTC. Due to concerns about metastatic disease, a positron-emission tomography (PET)-CT was conducted, revealing hypermetabolic lesions in numerous bilateral lung nodules, right thyroid nodule, porta hepatis lymph node, and a soft tissue nodule within the greater curvature of the gastric body. Subsequent biopsies of the right lung and gastric body confirmed the diagnosis of metastatic melanoma. On further questioning, it was found that the patient had a history of a skin lesion on his back that was excised several years ago with pathology reporting tumoral melanosis. Malignant melanoma has a poor prognosis due to high recurrence and metastatic rates. In melanoma, TERT promoter mutations are the most common mutations in noncoding regulatory regions. TERT C228T mutations and C250T mutations are seen in malignant melanoma and studies have shown that TERT promoter mutations are associated with aggressive clinical behavior. These TERT promoter mutations can also be seen in various other cancers including primary thyroid cancers with a similar association with more aggressive thyroid tumor characteristics. Our case describes a patient with a thyroid nodule and molecular testing noting a TERT promoter mutation. Both primary thyroid cancer and metastatic disease to the thyroid should be considered in these cases. This case also highlights the importance of obtaining a thorough history of prior malignancy in patients with thyroid nodules to assess the risk of metastatic disease. Presentation: 6/1/2024

9182 Metastatic Extra-Gastrointestinal Stromal Tumor Presenting As Hypoglycemia

Abstract Disclosure: O. faour: None. D. John: None. S.K. Suryanarayanan: None. A.A. Rizvi: None. Introduction: Non islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome seen in association with solid abdominal tumors of mesenchymal and epithelial origin. We report a case of metastatic extra-gastrointestinal stromal tumor (E-GIST) presenting with severe hypoglycemia as its initial manifestation. CASE DESCRIPTION: A 46-year-old patient was found to have a blood glucose of <45 mg/dl during a routine clinic visit with her primary care physician. Although she was asymptomatic, she was sent to the emergency room (ER) for further evaluation. She had a history of prediabetes managed by lifestyle modification. She has been experiencing multiple episodes of hypoglycemia previously which fulfilled the Whipple’s triad in the preceding months. These hypoglycemic episodes included loss of unconsciousness, falls in the shower with head injury, and several hospital visits. Serum glucose in the ER was 14 mg/dl and hypoglycemia persisted despite continuous dextrose solution. Physical examination was notable for a distended, non-tender abdomen and cervical lymphadenopathy. CT scan showed a 15 cm mass in the liver, multiple large masses in the mesentery, and a 11 cm lesion in the left pelvis. There were enlarged lymph nodes in the abdomen, chest, and neck. Serum chemistries drawn when the patient was hypoglycemic revealed potassium level of 2.7 mg/dl (3.5-5.5) an insulin level of <1.0 mIU/L (5-25), C-peptide <0.1 ng/mL (0.5-2), cortisol 13.8 mcg/dL (5-25), and insulin-like growth factor-2 (IGF-2) was 270 ng/mL (38-267). The IGF-2/IGF-1 molar ratio was 3.4 (normal <3:1). The sulfonylurea drug screen came back negative. Upper and lower endoscopies were unrevealing. Biopsy of the liver lesion showed cytology and immunohistochemical findings consistent with a epithelioid metastatic extra-gastrointestinal stromal tumor. A provisional diagnosis of NICTH was made. The patient responded well to intravenous glucose, oral carbohydrate intake and high-dose corticosteroids. She was subsequently started on therapy with the tyrosine kinase inhibitor (TKI) imatinib. Discussion: Paraneoplastic hypoglycemia is often seen in association with metastatic epithelial and mesenchymal tumors. IGF-2 and incompletely processed pro-IGF-2 activates autocrine, paracrine, and endocrine pathways that lead to tumor growth, fasting hypoglycemia, rarely of acromegalic features. Treatment with octreotide, diazoxide, and glucagon is generally ineffective, while glucocorticoid use and surgical intervention are helpful in ameliorating the hypoglycemia. Tumor-directed therapy with TKIs, primarily imatinib, appears promising in achieving remission. Our case is a clinical reminder that hypoglycemia secondary to NICTH can be the predominant presenting feature in patients with underlying E-GIST. Presentation: 6/3/2024

CYRAD: a translational study assessing immune response to radiotherapy by photons or protons in postoperative head and neck cancer patients through circulating leukocyte subpopulations and cytokine levels

BackgroundRadiotherapy has both immunostimulant and immunosuppressive effects, particularly in radiation-induced lymphopenia. Proton therapy has demonstrated potential in mitigating this lymphopenia, yet the mechanisms by which different types of radiation affect the immune system function are not fully characterized. The Circulating Immunes Cells, Cytokines and Brain Radiotherapy (CYRAD) trial aims to compare the effects of postoperative X-ray and proton radiotherapy on circulating leukocyte subpopulations and cytokine levels in patients with head and neck (CNS and ear nose throat) cancer.MethodsCYRAD is a prospective, non-randomized, single-center non interventional study assessing changes in the circulating leukocyte subpopulations and cytokine levels in head and neck cancer patients receiving X-ray or proton radiotherapy following tumor resection. Dosimetry parameters, including dose deposited to organs-at-risk such as the blood and cervical lymph nodes, are computed. Participants undergo 29 to 35 radiotherapy sessions over 40 to 50 days, followed by a 3-month follow-up. Blood samples are collected before starting radiotherapy (baseline), before the 11th (D15) and 30th sessions (D40), and three months after completing radiotherapy. The study will be conducted with 40 patients, in 2 groups of 20 patients per modality of radiotherapy (proton therapy and photon therapy). Statistical analyses will assess the absolute and relative relationship between variations (depletion, recovery) in immune cells, biomarkers, dosimetry parameters and early outcomes.DiscussionPrevious research has primarily focused on radiation-induced lymphopenia, paying less attention to the specific impacts of radiation on different lymphoid and myeloid cell types. Early studies indicate that X-ray and proton irradiation may lead to divergent outcomes in leukocyte subpopulations within the bloodstream. Based on these preliminary findings, this study aims to refine our understanding of how proton therapy can better preserve immune function in postoperative (macroscopic tumor-free) head and neck cancer patients, potentially improving treatment outcomes.Protocol versionVersion 2.1 dated from January 18, 2023.Trial registrationThe CYRAD trial is registered from October 19, 2021, at the US National Library of Medicine, ClinicalTrials.gov ID NCT05082961.

The preoperative recurrence score: Predicting early recurrence in peri-hilar cholangiocarcinoma

IntroductionDespite advances in surgical techniques, the rate of early recurrence in perihilar cholangiocarcinoma (PCC) remains high. We sought to develop the Preoperative Recurrence Score (PRS), a model to estimate the risk of early recurrence after resection based on preoperative radiological characteristics. Materials and methodsData of patients who underwent surgery for PCC were retrospectively collected, and preoperative imaging was reviewed to assess tumor characteristics. A model to assess the risk of early recurrence based on preoperative radiologic characteristics was internally developed and externally validated on two cohorts of patients from two European major hepatobiliary surgery referral centers. ResultsA total of 215 patients among three different patient cohorts were included in the study. Tumor size ≥18 mm (HR 2.70, 95 % CI 1.48–4.92, p = 0.001), macroscopic portal vein involvement (HR 2.28, 95%CI 1.19–4.34, p = 0.013), hepatic arteries involvement (HR 2.44, 95%CI 1.26–4.71, p = 0.008), and presence of suspicious lymph nodes (HR 1.98, 95%CI 1.02–3.83, p = 0.043) were significantly associated with recurrence-free survival (RFS). The model showed excellent discrimination both on the internal (AUC 0.83) and external validation cohorts (external 1: AUC 0.84; external 2: AUC 0.70). High PRS was associated with worse RFS among all three cohorts, with a 1-year recurrence probability of 80.1 %, 100.0 %, and 54.2 % in the internal and external validation cohorts 1 and 2, respectively. ConclusionsThe PRS is a simple tool that can accurately assess the risk of early recurrence in patients with PCC. Up-front surgery should be carefully evaluated in patients with high PRS, as it could result in a futile resection.

8097 A Rare Case of a Renal Cell Carcinoma and Pheochromocytoma Collision Tumor

Abstract Disclosure: R. Daas: None. S. Logan: None. W. Sexton: None. V. Chumbalkar: None. M. McGettigan: None. C. Veloski: None. Background: Collision tumors are neoplasms comprised of two or more distinct tumors. A collision tumor consisting of a renal cell carcinoma and pheochromocytoma is extremely rare with less than five cases reported in the literature. Clinical Case: A 64-year-old male with a history of hypertension and type 2 diabetes presented with hematuria. The patient was on 4 anti-hypertensive medications at the time. He noted increased road rage, anxiety, tremors, and insomnia. A CT abdomen/pelvis revealed an exophytic 8.6 x 7.9 cm left upper pole renal mass and a 7.5 x 6.2 cm left adrenal mass. Contrast-enhanced MRI abdomen showed a left upper/interpolar renal mass with heterogenous peripheral enhancement, restricted diffusion, and areas of central necrosis along with a heterogenous, enhancing left adrenal mass with associated restricted diffusion and areas of cystic necrosis. Both masses had associated areas of hyperintense signal on T1 fat-suppressed MRI suggestive of hemorrhage. Lab work revealed ACTH 26.6 pg/mL (7.2-63.3), cortisol 13 ug/dL (3.7-19.4), aldosterone 23.1 ng/dL (4-31), renin 4 ng/mL/hr (0.5-4), dopamine 136 pmol/L (<240), epinephrine 121 pmol/L (<330), norepinephrine 23,666 pmol/L (1050-4800), plasma normetanephrines 12.3 nmol/L (0-0.89), plasma metanephrines <0.10 nmol/L (0-0.49), 24-hour urine normetanephrines 4,178 mcg (122-676) and 24-hour urine metanephrines 4,233mcg (224-832). The patient was treated with alpha blockade prior to left radical nephrectomy, left adrenalectomy and infrahilar paraaortic lymph node dissection. Despite aggressive preoperative alpha blockade with maximal doses of doxazosin, addition of metyrosine and other anti-hypertensives, he developed acute hypertension with adrenal mass manipulation during the procedure and then hypotension following removal. He was admitted to the ICU for management of hypotension with pressors and fluid resuscitation and did well. Post-operative labs showed plasma normetanephrines 0.98 nmol/L (0.00-0.89) and plasma metanephrines 0.11 nmol/L (0.00-0.49). Pathology revealed clear cell renal cell carcinoma (RCC) of the kidney. The adrenal gland showed 2 tumors; one consistent with pheochromocytoma and another intimately associated with the former consistent with metastatic RCC, morphology diagnostic of a collision tumor. Following surgical resection, the patient was referred for genetic testing, surveillance imaging and lab testing, and treated with pembrolizumab adjuvant therapy for stage IV RCC. Conclusion: Although collision tumors are rare, biochemical testing to rule out a pheochromocytoma must be performed for all indeterminate adrenal masses and presumed adrenal metastases of active malignancies. Presentation: 6/2/2024

7633 Novel CASR Gene Mutation in a patient with Familial Hypocalciuric Hypercalcemia and Papillary Thyroid Cancer

Abstract Disclosure: A. Parihar: None. E.S. Nylen: None. S.M. Gandhi: None. Familial Hypocalciuric Hypercalcemia (FHH) is predominantly caused by loss-of-function mutations in the calcium-sensing receptor (CaSR) characterized by a benign elevation in calcium and PTH which can be mistaken for primary hyperparathyroidism (PHPT). Missense mutations in the CaSR gene causing FHH have been documented but not much is known regarding their clinical significance. We describe a patient with FHH found to have a novel variant mutation. A 37-year-old male with hypogonadism and fatty liver was incidentally found to have hypercalcemia suggestive of PHPT with elevated PTH (102-114 pg/ml), normal vitamin D, and Fractional Excretion of Calcium (FECa) of 0.014. His father also had hypercalcemia and had undergone parathyroid surgery. The patient denied kidney stones and had a normal bone density. Subsequent Sestamibi and 4D CT scan suggested parathyroid adenoma on the left mid-lower pole of the thyroid. Neck ultrasound also showed a left 1.2 x 1 x 1 cm thyroid nodule as well as a left neck mass with calcifications. Fine needle aspiration was positive for metastatic Papillary thyroid cancer(PTC) in the left neck mass and patient underwent total thyroidectomy along with subtotal parathyroidectomy and lateral neck dissection. Thyroid pathology confirmed multifocal PTC with lymph node involvement that were BRAF V600 positive. Parathyroid pathology was benign hyperplasia. The PTH level decreased appropriately intraoperatively (69%), but postoperatively a rise was noted with levels remaining 70-90 pg/ml with normal calcium levels. Repeat FECa was 0.007, supporting the diagnosis of FHH. Given patient’s father also had hypercalcemia, genetic testing was pursued. This revealed CaSR gene missense mutation (c.1382T>C p.Leu461Pro, heterozygous). This variation is not present in population databases and has been classified as a variant of uncertain significance. It can be difficult to distinguish PHPT from FHH based on FECa as in this case. The patient also had PTC which is not known to be associated with FHH. Due to uncertain significance of this novel CaSR missense mutation, long term follow-up and further familial genetic testing will help better understand clinical implications. Presentation: 6/2/2024