Left Neck Mass Research Articles

Case report: Microsurgical resection of a giant triple dumbbell shaped jugular foramen Schwannoma via retrosigmoid and transcervical approach

The surgical management of extensive jugular foramen schwannomas presents a formidable challenge, aiming for gross total resection while minimizing complications. Here, we present a case with giant triple dumbbell-shaped jugular Foramen Schwannoma. A 45-year-old male with a one-year history of a left neck mass underwent surgery. Initial misdiagnosis of submandibular gland inflammation led to persistent symptoms despite anti-inflammatory treatment. Imaging revealed a large lesion in the left cerebellar peduncle-neck-jugular foramen region (39.6 x 26.2 x 90 mm). The combination of retrosigmoid and transcervical approach was selected. Sufficient drilling of the infralabyrinthine, retrofacial area of the mastoid with facial nerve transposition is important for the safe gross total removal of the tumor. The patient underwent a gross total removal of the tumor. Facial nerve function was preserved. Although dysphagia and hoarseness complicated postoperatively, he became able to take foods orally after the surgery. In conclusion, this case underscores the successful surgical approach for a large jugular foramen Schwannoma, emphasizing the importance of precise techniques to achieve complete tumor resection while minimizing postoperative complications.

Liver Metastasis Masking as Neuroendocrine Carcinoma (NEC) Predates Discovery of Intra/Peri-Thyroid Thymic Carcinoma (ITTC)

Abstract Introduction/Objective Intrathyroidal thymic carcinoma (ITTC) also known as Carcinoma showing Thymus-Like differentiation (CASTLE) is a rare malignancy comprising 0.1 to 0.15% of thyroid cancers. The WHO 5th Edition emphasizes that these tumors may also occur outside the thyroid typically at the lower pole Methods/Case Report Our aim is to show that NEC is a mimic of ITTC; that CD5, c-KIT (CD 117), p40, CK5/6 expression distinguishes ITTC from NEC, and that ITTC may at times express NE markers. Briefly, a 51-year-old man presented with hoarseness left neck mass and a PET avid liver lesion in 2016. Biopsy of the neck and liver masses revealed an infiltrating poorly differentiated “NEC” with similar morphology; positive for p53, chromogranin, and synaptophysin; negative for cam5.2, thyroglobulin, TTF-1, CD20, Pax5, CD3, CD5, S-100, calcitonin, CD56, p16, p63, c-KIT (CD117), AE1/3; and 100% staining for Ki-67. The patient underwent chemotherapy, responded well, remained under surveillance, and was symptom-free in the interim. A new 2.1 x 2.0 cm nodule appeared at the left thyroid lower pole after 6 years. The tumor was positive for CD5, CD117, p40, CK5/6, with > 95% Ki67 expression. Chromogranin, synaptophysin, CD56, thyroglobulin, calponin, TTF1, and Epstein Barr virus were negative and was overall diagnostic of ITTC Results (if a Case Study enter NA) NA Conclusion This shows the diagnostic dilemma of distinguishing ITTC from NEC which may share expression of neuroendocrine (NEC) markers and that positivity for CD5, c-KIT (CD117), p40, and CK5/6 are key diagnostic features of ITTC.

DICER-1 Mutation Associated Sarcoma of Thyroid in An Adult Male

Abstract Introduction/Objective DICER-1 is an autosomal dominant tumor predisposition syndrome caused by germline DICER1 mutations. In the thyroid, it is associated with an early-onset multinodular goiter (MNG) and low-grade thyroid carcinomas. The aggressive variants thyroblastoma and poorly differentiated carcinoma are however seen in the pediatric age group. We report a case of DICER-1-associated (rhabdomyo) sarcoma without primitive components in an adult male. Methods/Case Report A 44-year-old healthy male with a family history of MNG, presented with a large left neck mass confirmed on imaging with largest 6.4cm, and extension into the mediastinum. FNA showed a malignant spindle cell- rich neoplasm with negative expression for Keratins, TTF-1, PAX-8, Calcitonin, INSM- 1 and SOX-10. The CEA and calcitonin were normal. The lymphoma was excluded by flow cytometry. The patient underwent a left thyroidectomy with central and left selective neck dissection. On gross examination, the left lobe of the thyroid was replaced by a tan- white, partially encapsulated solid mass. Microscopic examination revealed nests and sheets of ovoid to spindle- shaped cells with eosinophilic cytoplasm in fascicles with hypocellular areas with loose stroma. Foci of rhabdomyoblastic differentiation with straps cells, positive for desmin and myogenin were identified. Brisk mitotic activity and tumor necrosis were present. No primitive thyroid epithelium or blastemal component was identified. Tumor cells were negative for S100, SOX10 CD34, CD31, SMA, calponin, CD99, NKX2.2, SS18-SSX which excluded malignant peripheral nerve sheath tumor, angiosarcoma, leiomyosarcoma, Ewing’s sarcoma, and synovial sarcoma. Next-generation sequencing showed a DICER1 c.4517G>A (p.W1506) and c.5437G>C (p.E1813Q) mutation, both variants reported as germ-line variants. A final diagnosis of DICER-1-associated rhabdomyosarcoma was rendered. The patient underwent rehabilitation at another facility and lost to follow-up. Results (if a Case Study enter NA) NA Conclusion The case highlights the expanding spectrum of DICER-1-associated malignant tumors and the importance of keeping it in the differential diagnosis of unusual malignant tumors of the thyroid even in adults.

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

7962 Transformation of Poorly Differentiated Papillary Thyroid Carcinoma to Anaplastic Thyroid Carcinoma, an Atypical Course!

Abstract Disclosure: T. Altaweel: None. S. Makadsi: None. M. Hussein: None. J. Samantray: None. Introduction: Anaplastic thyroid cancers are undifferentiated, rare and aggressive. The transformation of papillary thyroid cancer to anaplastic thyroid cancer is documented in literature, however, rare. In this report, we present a case of Anaplastic thyroid carcinoma likely arising from a co-existing poorly differentiated Papillary carcinoma. Case Presentation: A 74-year-old male with past medical history of tobacco smoking who presented with the onset of voice hoarseness for 6 months. He has also noticed a left neck mass that is in the mid supraclavicular region. A Neck CT neck was performed at the time of presentation and was significant for a 4.6x3.4x5.9 cm left thyroid mass with displacement of the trachea. FNA biopsy showed papillary carcinoma with focal features of Tall Cell Variant. Poorly differentiated components with fragments of stroma and muscle were seen and suggested invasion. These findings raised the possibility of anaplastic thyroid carcinoma in the setting of papillary carcinoma and poorly differentiated carcinoma. BRAF V600E pathogenic variant mutation along with TERT mutation were found. Patient underwent direct laryngoscopy, bronchoscopy with biopsies, and tracheostomy with surgical pathology confirming papillary thyroid cancer with muscles invasion. Combination dabrafenib and trametinib were started. No surgical resection of thyroid tissue was planned. A follow up CT showed a significant decrease in the low-density soft tissue involving the medial thyroid gland bilaterally, consistent with interim positive response to therapy. Three months later, CT neck showed near complete resolution of low-density soft tissue involving the medial thyroid and parathyroid glands and subglottic trachea consistent with further interim positive response to therapy. Six months post initiation of therapy, CT Neck showed focal low density in the mid and inferior right thyroid gland which may represent residual and/or recurrent thyroid carcinoma. That density was further demonstrated on a repeat CT neck as a 1.8 cm hypodense nodule in the inferior right thyroid gland and concerning for recurrent thyroid tumor with possible infiltration of the trachea. Conclusion: ATC prognosis is affected by many factors such as metastasis, age, treatment strategies, socioeconomic status and the presence of BRAF V600E and TERT mutations. Diagnosis can be challenging. Our patient presented months after his symptoms started and this is an atypical course of Anaplastic Thyroid Carcinoma as it usually progresses aggressively and rapidly. Given the pathology reports and the more slow presentation of this patient’s carcinoma, it can be suggested that this is a case of papillary carcinoma with a later transformation to ATC. In these cases, surgical resection Presentation: 6/2/2024

12205 Challenging Case Of Anaplastic Thyroid Cancer With Unusual Histological Features: A Diagnostic Dilemma With High Grade Sarcoma

Abstract Disclosure: B. Gautam: None. B. Tiwari: None. M.S. Hossain: None. S. Hossain: None. S.C. Kumar: None. H. liao: None. Introduction: Anaplastic thyroid carcinoma (ATC) is a rare but highly aggressive thyroid cancer accounting for < 2% of cases, characterized by its rapid growth, extensive local invasion, and poor prognosis. Distinguishing ATC from other high-grade sarcomas, such as leiomyosarcoma, is challenging due to shared morphological features and overlapping immunoprofiles. We present a case involving a 73-year-old male presenting with rapidly growing neck mass, leading to diagnostic challenges differentiating between ATC and high-grade sarcomas. Case presentation: A 73-year-old male presented to ED with a rapidly growing painful neck mass for last 3 months, associated with dysphagia, dyspnea & dysphonia. He denied any fever, chills, weight loss and symptoms of hyperthyroidism or hypothyroidism. No personal or family history of thyroid cancer. On physical exam: vitals were normal, Neck exam revealed a left sided neck mass, mobile with deglutition, hard in consistency associated with hoarseness of voice. No stridor or wheeze noted on auscultation. Physical exam was otherwise normal. Laboratory tests showed normal CBC, CMP and TSH 1.45 mIU/L, T4 9.7 ug/dl. CT neck with contrast showed 5.4 x 5.6 x 8.2 cm large lobulated left thyroid mass with rightward airway deviation & substernal extension. Ultrasonogram of thyroid showed 9.6 x 5.3 x 3.3 cm left thyroid lobe with internal calcifications & extrathyroidal extension with several abnormal appearing cervical lymph node, largest measuring 4.9 x 2.4 x 3.3 cm. CT chest/abdomen/pelvis with contrast showed multiple bilateral lung nodules measuring up to 1.5 cm and 1.4 x 1.3 cm left gluteal soft tissue mass. IR-guided left neck mass biopsy was suggestive of primary spindle cell neoplasm with initial immunoprofiles consistent with a high-grade sarcoma, favoring leiomyosarcoma. Given the rapid growth of the neck mass with associated dyspnea, left thyroidectomy was performed and surgical pathology was suggestive of a high-grade sarcoma. However, subsequent pathology review made a final diagnosis of ATC, based on morphologic & immunohistochemical profile showing tumor cells strongly positive for p53 and Desmin with few cells positive for PAX-8, Cam 5.2 and CD68, and negative thyroglobulin, TTF-1, CK7, CK20, CK MNF116, pancytokeratin AE1/AE3 and CK5/6. Thyroseq revealed a distinctive molecular profile specifically positive for TERT and TP53 supporting diagnosis of ATC. Discussion: This case highlights the diagnostic dilemma posed by the resemblance between ATC and high-grade sarcomas due to overlapping clinical, morphological and immunohistology features. While both malignancies may exhibit similar morphological features, specific immunohistochemistry profiles along with molecular testing aid in distinguishing between them and guiding appropriate treatment strategies. Presentation: 6/1/2024

Analysis of Diagnosis and Treatment Strategies for Parapharyngeal Space Tumors With Follicular Dendritic Sarcoma

Background: Parapharyngeal space tumor is a tumor that occurs in the parapharyngeal space. Parapharyngeal space tumors are uncommon, accounting for about 0.5% of head and neck tumors. Eighty percent of them are benign and 20% are malignant. The pathologic types of tumors are varied, mainly neurogenic tumors and salivary gland tumors. Follicular dendritic sarcomas are much rarer, with an inert biological behavior and a low-grade malignant sarcoma. Clinicians face difficulties in the management of this lesion. Therefore, a comprehensive analysis of the management of this disease is necessary. Case presentations: In May 2023, a 22-year-old male presented with pharyngeal discomfort, dysphagia, and sleep apnea. The patient underwent MRI which showed a rounded hypodense shadow with a size of 3.2×2.1×4.5 cm in the left lateral pharyngeal wall and a mass located in the posterior aspect of the left submandibular gland. After preliminary diagnosis of left parapharyngeal space tumor and left neck mass, the clinician performed transoral endoscopy-assisted resection of the left parapharyngeal space tumor and transcervical resection of the left cervical mass. The patient has been followed up without recurrence. Conclusions: This case provided a reference for the diagnosis and management of parapharyngeal space tumors. In particular, new insights into the diagnosis and management of a rare pathologic type were presented, which had the potential to improve the overall understanding of this disease.

SOLAMEN syndrome in a toddler

BackgroundSegmental overgrowth, lipomatosis, arteriovenous malformation, and epidermal nevus (SOLAMEN) syndrome is a segmental overgrowth syndrome that is part of Cowden’s Syndrome, a subset of the PTEN hamartoma tumor syndrome cluster. Due to SOLAMEN disease’s rarity, clinical suspicion should arise if multiple small nonspecific variably low-attenuated nodular lesions in the back, shoulders, and upper arms are present on CT, which are associated with mucocutaneous lesions. We present a rare case of SOLAMEN syndrome with widespread lipomatous growth, greater than reported in literature, with confirmed PTEN genetic testing.Case presentationWe describe a case of a 2-year-old boy with a slowly growing left neck mass since birth. Physical exam revealed macrocephaly and epidermal nevi on left axilla, arm, and fingers, appearing as pink verrucous and has visible veins on chest wall/abdomen. CT and MRI imaging showed a lipomatous hibernoma extending from the leftward neck to the abdominal cavity, encasing vascular structures form the left carotid and subclavian arteries to the diaphragmatic hiatus, in addition to the spleen and kidney. Biopsy of the left shoulder revealed hibernoma, a fatty neoplasm of benign brown fat. Patient had a resection of his left shoulder hibernoma and is currently asymptomatic, undergoing surveillance.ConclusionDue to SOMAMEN syndrome’s rarity, clinical suspicion should arise if a patient presents with multiple small-nonspecific variably low-attenuated nodular lesions on CT and mucocutaneous lesions. Ongoing monitoring should be done as there is an increased risk of cancer.

A Rare Presentation of Metastatic Breast Carcinoma to the Thyroid Three Years after Mastectomy: A Case Report

Abstract Introduction: Breast cancer is the most common cancer in women. Yet, metastasis to the thyroid is a rare occurrence. Here we present the case of a patient with breast cancer metastasis to the thyroid gland to discuss the management of such presentations compared to the current literature. We also present this case to add to the existing literature and aid in the expansion and better understanding of rare incidences as such. Presentation of Case: A 38-year-old female with no chronic medical illnesses was diagnosed with invasive ductal carcinoma of the right breast T3N0M0 in 2017. Chemotherapy eight cycles of neoadjuvant chemotherapy followed by right simple mastectomy, sentinel lymph node biopsy, and adjuvant radiation to the chest wall. The patient has been on hormonal therapy since diagnosis. In 2020, the patient presented with a left neck mass and underwent a total thyroidectomy. Pathological analysis of the specimen confi rmed the presence of poorly differentiated cells consistent with mammary ductal cells while the right thyroid lobe demonstrated features of papillary thyroid carcinoma. Conclusion: Intrathyroidal metastasis of extrathyroidal cancers is rare but should be considered when patients are present with a history of cancer. Thyroidectomies in isolated secondary thyroid cancers have been shown to prolong the disease-free period but are not a defi nitive cure

Salivary gland secretory carcinoma presenting as a cervical soft tissue mass: a case report

BackgroundSecretory carcinoma (SC) has been described as a distinct salivary gland tumor in the fourth edition of the World Health Organization (WHO) classification of head and neck tumors. SC is generally considered as a slow-growing low-grade malignant tumor, while several cases have been reported with high-grade features, and even metastases in the literature up until now. In this article, a soft tissue SC case is discussed with high-grade microscopic features and neural invasion. A review of the salivary gland SC cases with aggressive behavior is also debated.Case presentationA 65-year-old Caucasian man presented with a left neck mass for the past six months. The imaging studies demonstrated a very large cystic cervical mass (46 × 23 mm) with papillary projections in the anterolateral aspect of the left neck zone Vb. He underwent left radical neck dissection (level I-V) and was followed up for 12 months with the diagnosis of Secretory carcinoma.ConclusionAlthough SC generally has a good outcome, multiple recurrences and unusual metastases may occur, which should be considered by either the pathologists or clinicians.

Abstract 286: Endovascular Management of Pediatric Vertebro‐Vertebral Arterio‐Venous Fistula: Case report

Introduction Vertebro‐vertebral arteriovenous fistula (VV‐AVF) is a rare vascular malformation with abnormal high flow shunt between extracranial vertebral artery and an adjacent vertebral vein plexus without intervening capillaries.1 While seen in both adult and pediatric populations, the majority of the VV‐AVFs seen in childhood are largely congenital, seen in the setting of connective tissue diseases such as Ehler‐Danlos Syndrome, Neurofibromatosis type 1, and Marfan’s syndrome, with abnormal involution of the proatlantal system also thought to be implicated.2,3,4 Approximately 70% of the presenting population are symptomatic at presentation, with a pulsatile mass over the side of the neck or pulsatile tinnitus. Additionally, symptoms of vertebrobasilar insufficiency including gait abnormalities, limb weakness, vertigo, recurrent vomiting, diplopia, and in severe cases, cardiac decompensation can also be seen.5 Methods This is a case report of a 2‐year‐old boy presented to our pediatric neurovascular center of excellence with a progressively enlarging pulsatile left neck mass appreciated a year ago. Further evaluation with neck MRA followed by catheter cerebral angiogram revealed an upper cervical AVF with primary arterial feeders from V3 segment of the left vertebral artery, enlarged left occipital artery, and retrograde filling via the right vertebral artery into the left V4 with a direct shunt into a large venous pouch which drained into the vertebral venous plexus. Results Given the progressive enlargement of the mass, location of AVF, and concern for detrimental subsequent venous congestion, decision was made to pursue elective endovascular embolization of the VV‐AVF. The goal was set to obtain complete occlusion of the venous pouch to obliterate all arterial inflow contribution and prevent further recruitment. Occipital artery catheterization was attempted however given the redundant anatomical loops; optimum microcatheter navigation was not feasible. Given the non‐dominant configuration of the left VA, along with the presence of left AICA‐PICA system off the basilar trunk, coil embolization of the venous pouch followed by sacrifice of the V3 segment left VA was achieved satisfactorily leading to obliteration of the AVF along with all the arterial contributions from bilateral vertebral arteries and left occipital artery (Figure‐1). Given the potential vertebrobasilar inadvertent embolization, the procedure was performed under continuous neurophysiological monitoring and post‐periprocedural therapeutic anticoagulation. The patient tolerated the procedure well without any intraoperative issues. He was monitored in the pediatric ICU for 24 hours after the procedure, and subsequently discharged home. Conclusion We report a successful endovascular coil embolization of a VV‐AVF. To our knowledge, this is the youngest reported case where endovascular technique was successfully utilized to achieve cure of such high flow VV‐AVF in this 2‐year‐old patient. Systematic and methodical angiographic analyses with close post‐procedural monitoring are pivotal in ensuring successful outcomes.

SAT487 A Case of Mistaken Identity: A Rare Presentation of Ectopic Thyroid Tissue

Abstract Disclosure: N. Doshi: None. R. Azimzade: None. A. Rajpal: None. Background: Ectopic thyroid tissue (ETT) lateral to the midline is very rare, and its presence at the carotid bifurcation is exceedingly unique. Paraganglioma is the most common primary tumor at the carotid bifurcation, often called a carotid body tumor. We hereby present a case of lateral ETT with radiological features similar to paraganglioma. Case Description: A 72-year-old female with history of GERD was referred to us for evaluation of a well-circumscribed, slightly tender left neck mass. She has had the mass for approximately 15 years with previous evaluation with ultrasound in Yemen, where she was told to undergo surgery to remove it. She did not pursue surgery at that time. She moved to the U.S. one year ago and was re-evaluated for the neck mass. On examination, a firm mass was noted on the left side of the neck, followed by an ultrasound which demonstrated a 4.5 cm mass at the left carotid bifurcation and an enlarged right thyroid lobe of the same echogenicity with no tissue in the left thyroid bed. She had no clinical symptoms suggesting of hypo or hyperthyroidism. Laboratory examination showed suppressed TSH with elevated T3 suggesting thyrotoxicosis. CT neck was obtained for further characterization of the left neck mass which showed a hyper-enhancing, lobular soft tissue mass at the carotid bifurcation extending from the mandible to the level of the thyroid isthmus, concerning for carotid body paraganglioma or schwannoma. An I-123 scan demonstrated 24% (increased) uptake in the right thyroid lobe and minimal uptake in the carotid bifurcation tissue. The patient is currently being treated medically for thyrotoxicosis. Based on its ultrasonographic appearance, mild uptake on the I-123 scan, and no clinical suggestion of paraganglioma, the left neck mass is presumed to be ETT and no surgical intervention is being pursued. It is possible that the right lobe is thyrotoxic, suppressing iodine uptake in the ectopic tissue. Conclusion: This case demonstrates a unique presentation of ETT in the left carotid bifurcation with a thyrotoxic right lobe. It is difficult to distinguish the precise composition of neck masses at the carotid bifurcation, which has important implications for management. Often, an official diagnosis of thyroid tissue is made with histopathology only after the mass is surgically excised. Most ETT is benign in nature, and many times it is the only thyroid tissue available, thus surgery is not indicated. It is especially difficult to distinguish between ETT and paraganglioma on imaging itself. Somatostatin receptor scintigraphy, Ga-68/PET scanning, or iodine uptake scan can be useful to distinguish ETT from paraganglioma. Despite its rarity, lateral ETT must be included in the differential diagnosis of carotid body paraganglioma. Presentation Date: Saturday, June 17, 2023

FRI368 Thyroid Paraganglioma: A Rare Manifestation Of Paraganglioma Syndrome Associated With SDHD Mutation

Abstract Disclosure: K. Samuel: None. C. McMullen: None. C. Veloski: None. S. Kushchayev: None. J.E. Hallanger-Johnson: None. J. Hernandez Prera: None. J. Muzaffar: None. G.Q. Yang: None. V. Tarasova: None. Background: Thyroid paragangliomas (TP) are exceptionally rare, representing 0.5% of all paragangliomas (PGL) with total of less than 70 cases reported to date. We report a case of a TP presenting with an indeterminate thyroid nodule, as a first manifestation of multifocal head and neck PGL, associated with succinate dehydrogenase complex subunit D (SDHD) mutation. Clinical case: A 59-year female was initially seen at the tertiary referral center for an indeterminate thyroid nodule discovered incidentally on neck ultrasound (US) ordered for evaluation of a palpable posterior left neck mass. Neck/thyroid US showed multiple nonspecific bilateral lymph nodes measuring up to 1.2 cm and a 1.7 cm right interpolar markedly hypoechoic and hypervascular solid thyroid nodule (TR5). Clinically, the patient did not have symptoms related to the thyroid nodules or lymph nodes in the neck. Thyroid function tests were within normal range. An US-guided FNA biopsy was nondiagnostic. Core biopsy was suspicious for papillary thyroid carcinoma (hypercellular thyroid parenchyma with some follicular cells with nuclear irregularity, grooves, and hyperchromasia). Pathology slides review at the tertiary center showed nondiagnostic sample (Bethesda I) on cytopathology and neuroendocrine neoplasm consistent with PGL on core biopsy (immunohistochemical stains showed tumor cells positive for synaptophysin, chromogranin and GATA3. TTF1, TG, calcitonin, CEA and AE1/3 negative). US of the neck/thyroid 4 months later showed stable disease. Calcitonin and 24-h urinary catecholamines, metanephrines were within normal limits. There was no family history of pheochromocytoma or PGL. Genetic testing showed germline SDHD mutation (p.P81L(c.242c>5). 68Ga-DOTATATE PET/CT revealed multifocal areas of increased somatostatin receptor expression from the skull base to the left thoracic inlet, which included right and left skull base lesions, left neck level IIA lymph node, right and left level III lymph nodes, right thyroid lobe lesion, and left prevascular superior mediastinal lesion. An MRI of the brain and neck with and without contrast showed 1.7 cm right jugular, 0.6 cm right carotid, and 0.6 cm left vagal PGL, 1.3 cm right thyroid nodule, left level II 1.1x.6 cm lymphadenopathy, and 0.4 cm left superior mediastinal nodule. A CT of the neck w/contrast showed multiple areas likely representing bilateral carotid body tumors, left vagal PGL, right glomus jugular, and thyroid PGL stable over 6 months. MIBG nuclear medicine scan revealed no radiotracer accumulation in the lesions. EBRT therapy is planned to the skull base lesion. Conclusions: TP should be considered in the differential diagnosis of hypervascular thyroid nodules in patients with SDH-related pheochromocytoma-PGL syndromes. This case illustrates the importance of experienced multidisciplinary team evaluation and management of complex and rare PRG cases. Presentation: Friday, June 16, 2023

SAT547 Hereditary Paraganglioma: The Rare Co-Existence Of Two Genetic Syndromes Associated With PPGL-pheochromocytoma

Abstract Disclosure: K. Samuel: None. Hereditary Paraganglioma: the rare co-existence of two genetic syndromes associated with PPGL-Pheochromocytoma Kelara Samuel MD, Bryan McIver MD, Colleen Veloski MD, Julie Hallanger-Johnson MD, Valentina D. Tarasova, John Tourtelot MD, George Q. Yang MD, Sarimar Agosto-Salgado MD Background: Paragangliomas are neuroendocrine tumors arising from neural crest chromaffin cells of the autonomic ganglia and can be parasympathetic or sympathetic in nature. Approximately 30 percent of all paragangliomas are hereditary either associated with familial paraganglioma syndromes and other autosomal dominant syndromes, such as multiple neuroendocrine neoplasia 2A and 2B, neurofibromatosis type 1, and von Hippel Lindau disease.Case: A 73-year-old Hispanic female with a past medical history of hypothyroidism, hypertension, hyperlipidemia, and Lupus presented with a large neck mass of 11 years of evolution. An evaluation revealed a large near 12cm hypervascular, hyperenhancing left neck mass that encased the distal common carotid artery, carotid bifurcation, and internal and external carotid arteries and their branches. The multidisciplinary team recommended, given the tumor's extent, a non-surgical localized treatment consisting of radiation. Clinically, the patient had compressive symptoms, including tenderness over the tumor region, hoarseness, dysphagia, and changes in phonation. The patient also had a positive family history of paraganglioma in her grandson and nephew, but specific genetic alteration data from relatives was unavailable. Plasma normetanephrines were 0.68 (normal range 0-0.89), and plasma metanephrines were 0.23 (normal range 0-0.49). Genetic testing was positive for germline alterations in both SDHB p.Q214 and NF1 c.2970_2972delAAT. At this time, there is no evidence of metastatic disease and no clinical manifestations of NF1, suggesting a mild neurofibromatosis phenotype. Restaging imaging revealed an ongoing partial response to radiation and clinically patient has noted a significant improvement in the prior compressive symptoms. Conclusion: We present a case where we see an uncommon presentation of a non-secretory, hereditary paraganglioma with two concomitant rare genetic syndromes. This case highlights the importance of genetic testing for patient-appropriate tumor surveillance and family counseling implications. Presentation Date: Saturday, June 17, 2023

SAT210 A Case Of Recurrent Metastatic Parathyroid Cancer Complicated By Multiple Brown Tumors

Abstract Disclosure: A. Elmaaz: None. E. Bustamante: None. M. Batra: None. Introduction: Parathyroid cancer is a rare malignancy with about 25 % incidence of metastasis. Brown tumors are benign bone lesions caused by excessive bone turnover which are rarely associated with parathyroid carcinoma. Here, we present a case of recurrent metastatic parathyroid cancer complicated by multiple brown tumors. Case Presentation: A 63-year-old male presented with back pain, generalized weakness, and significant weight loss. Laboratory findings showed hypercalcemia 14.4 mg/dl, Alkaline phosphatase 253 U/L, and phosphorus 2.3 mg/dl. He was admitted to the hospital for hypercalcemia workup. MRI spine showed a heterogeneous mass arising from the left thyroid lobe and conglomerate lymph node, along with extensive metastatic sclerotic lytic lesions throughout the spine. MRI brain revealed multiple metastatic lesions in the skull base, facial bones, and the right angle of the mandible. Further workup revealed normal PSA, normal serum levels of free lambda and kappa light chains, and normal urine and serum protein electrophoresis. PTH levels, 2435.1 (8.7-77.1) pg/ml, and PTH-rP levels <1.1 pmol/l were noted. Ultrasound-guided FNA of the thyroid mass showed solid growth of malignant parathyroid cells strongly stained for PTH. Biopsy of the body of the T12 vertebra and mandibular lesions showed giant cell lesions of the bone with fibrous dysplasia, consistent with brown tumors. IV hydration, calcitonin, cinacalcet, and IV zoledronic acid started, followed by left hemithyroidectomy and left inferior parathyroidectomy. Surgical pathology was positive for parathyroid carcinoma invading the thyroid gland. His calcium and PTH levels post-surgery significantly improved. A few months later, the patient presented again with hypercalcemia and high levels of PTH. Sestamibi parathyroid scan showed no evidence of parathyroid adenoma. Because of enlarging left neck mass, confirmed by MRI neck, he then underwent excision of the left subcutaneous cervical lesion involving the left sternomastoid muscle. Surgical pathology was consistent with parathyroid carcinoma involving soft tissue. His calcium and PTH levels improved on subsequent follow-up visits. Conclusion: Parathyroid carcinoma is not a common cause of hypercalcemia. Though a rare entity, parathyroid cancer should be considered in the differentials of hypercalcemia and extremely high levels of PTH. Metastasis either locally or remotely should not be overlooked. Brown tumors could mimic bone metastasis and giant cell tumors; therefore, the clinical presentation is important for the diagnosis. Presentation: Saturday, June 17, 2023

A Case of Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Mycosis Fungoides with Large Cell Transformation Involving Cutaneous Lesions, and Metastasis to Lymph Node and Viscera

Large cell transformation (LCT) of mycosis fungoides (MF) is a histopathological transformation of neoplastic small lymphocytes with a clonally identical large cell phenotype, which is found in 20%–50% of cases of advanced MF. Some few cases and studies have been reported about the role of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18FFDG PET/CT) in diagnosing MF-LCT. This is a case of a 55-year-old man who had a left neck mass for 4–5 months. He underwent excisional biopsies on the skin and soft tissue. The histopathologic report showed MF-LCT. The 18F-FDG PET/CT findings revealed hypermetabolic lesions in the skin, cervical lymph node, and visceral organ. We introduce a rare case of MF-LCT involving both cutaneous and extracutaneous lesions.

PSAT288 Mucosa-associated Lymphoid Tissue Thyroid Lymphoma Presenting as a Rapidly Growing Neck Mass in an Asymptomatic Male Patient

Abstract A 77-year-old male was referred to endocrinology for a 2-month history of a rapidly enlarging painless left neck mass. His only other complaint was unintentional weight loss of 10 pounds over 12-months. On exam patient had a firm, smooth, nontender 2 cm thyroid/neck mass extending below left clavicle. No abnormalities were detected for right thyroid gland. There was no palpable lymphadenopathies or hepatosplenomegaly noted. No signs of tracheal, esophageal, or neck vein compression were noted. He did not have any history of radiation exposure, family history of thyroid-related disorders, or malignancy. Laboratory test including complete blood count, comprehensive metabolic profile and TSH were within normal limits. TPO antibody was positive. Ultrasound revealed a 7.7×4.1×4 cm hypoechoic spongiform mass replacing the left lobe of the thyroid, as well as scattered sub centimeter nodules. Contrasted CT of the neck confirmed 6.5×5.2×3.9 cm left thyroid mass causing mild rightward deviation of the trachea and extending into the superior mediastinum and no lymphadenopathy. FNA of the mass revealed presence of crushed lymphoid cells without thyroid follicular cells, which raised the possibility of chronic lymphocytic thyroiditis. FDG- PET scan showed intense, heterogeneous FDG uptake in the left neck mass (max SUV=10.7), likely arising from the left thyroid lobe concerning for thyroid malignancy without evidence of distant metastases. The patient underwent a left thyroid nodule core biopsy with subsequent left thyroid hemithyroidectomy. The pathology stains of the excised left thyroid lobe core biopsy showed extra nodal zone lymphoma of mucosa- associated lymphoid tissue (MALT Lymphoma) with extensive plasmocytic differentiation. Surgical path confirmed extra nodal zone lymphoma of mucosa-associated lymphoid tissue (MALT Lymphoma) with extensive plasmocytic differentiation and foci of chronic lymphocytic thyroiditis. Immunochemistry studies supported a diagnosis of plasma cell neoplasm or the plasma cell component of a B-cell lymphoproliferative disorder. Short-term follow-up FDG-PET and CT imaging demonstrated post-surgical changes without evidence of recurrence. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

PMON85 Co-occurrence of Carotid Body Tumor, Meningioma and Schwannoma in a Symptomatic Patient, Incidental Findings Vs Genetic Syndrome: A Case Report

Abstract Carotid body tumors, also known as chemodectomas/paraganglionomas; are rare neuroendocrine tumors that arise from parasympathetic ganglionic cells. They are usually benign with incidence of malignancy is <10%. In majority of cases, tumors are asymptomatic and found incidentally on clinical exam or radiological imagining. Their association with other non-neuroendocrine tumors as seen in present case; has not been well documented in literature. Case presentation 43 y/o female with PMH of GERD, obesity, asthma and anxiety disorder who came to endocrine clinic for left middle thyroid lobe nodule(0.9×0.6×0.6cm) evaluation; incidentally noted to have a multilobulated heterogeneous hypo echoic and iso-echoic mildly vascularized solid nodular mass (3.46×1.83×1.93 cm) in the left carotid bifurcation area; splaying the common and the internal carotid arteries on US. Review of systems was positive for left sided neck pain, intermittent palpitations, headaches, anxiety, and sleep disturbances. Clinical exam was remarkable for thyromegaly and a palpable non-tender 3cm left neck mass with no cervical lymphadenopathy. Initial labs were notable for mild elevation of chromogranin A (108.4 ng/ml) with normal levels of TSH, free T3, free T4, plasma metanephrines and 24-hour urinary metanephrines. Considering patient's persistent symptoms; plasma catecholamines levels were done and were negative. MRI soft tissue neck confirmed 2.8 cm lobular mass suggestive of paraganglioma. Metastatic work up was negative. Patient was referred for genetic testing considering young age and to rule out hereditary disorders. Interim, patient presented to the ED with complain of sudden onset lumbar backache without sphincteric involvement; neurological exam was unrevealing but on MRI lumbar spine found to have a 5.7×4.8×4cm lobulated well-circumscribed homogeneous soft tissue mass suggestive of schwannoma. Cervical and thoracic spine imaging was unremarkable. MRI brain showed a 1.1cm enhancing mass in right Meckel cave suggestive of meningioma. PET-DOTATATE scan was performed that revealed left neck mass as intensely avid, Right petrous apex mass as moderately avid and lumbar mass as not avid at all, consistent with the diagnosis of paraganglionoma, meningioma and schwannoma respectively. No evidence of DOTATATE avid nodal/ distant metastatic disease was found. Initially a hereditary etiology was suspected but genetic testing including (VHL, NF1/2, SDHD, SDHB) came back negative. Case was discussed with multidisciplinary teams; Neurosurgery service recommends conservative management of both meningioma and schwannoma at the moment considering benign course. Regarding paraganglioma, as tumor is non-secretory on repeated work up; sympathetic blockade is not warranted and patient is scheduled for pre-op embolization and surgical resection by Head and Neck surgery. Conclusion Paraganglionomas are generally benign non-secretory tumors that usually occur with other neuroendocrine tumors both as hereditary syndromes and sporadic cases. But their association with non-neuroendocrine tumors is mere incidental or has a genetic causation; is still unclear and warrants further research. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PMON85 Co-occurrence of Carotid Body Tumor, Meningioma and Schwannoma in a Symptomatic Patient, Incidental Findings Vs Genetic Syndrome; a case report.

Abstract Carotid body tumors, also known as chemodectomas/paraganglionomas; are rare neuroendocrine tumors that arise from parasympathetic ganglionic cells. They are usually benign with incidence of malignancy is <10%. In majority of cases, tumors are asymptomatic and found incidentally on clinical exam or radiological imagining. Their association with other non-neuroendocrine tumors as seen in present case; has not been well documented in literature. Case presentation 43 y/o female with PMH of GERD, obesity, asthma and anxiety disorder who came to endocrine clinic for left middle thyroid lobe nodule(0.9×0.6×0.6cm) evaluation; incidentally noted to have a multilobulated heterogeneous hypo echoic and iso-echoic mildly vascularized solid nodular mass (3.46×1.83×1.93 cm) in the left carotid bifurcation area; splaying the common and the internal carotid arteries on US. Review of systems was positive for left sided neck pain, intermittent palpitations, headaches, anxiety, and sleep disturbances. Clinical exam was remarkable for thyromegaly and a palpable non-tender 3cm left neck mass with no cervical lymphadenopathy. Initial labs were notable for mild elevation of chromogranin A (108.4 ng/ml) with normal levels of TSH, free T3, free T4, plasma metanephrines and 24-hour urinary metanephrines. Considering patient's persistent symptoms; plasma catecholamines levels were done and were negative. MRI soft tissue neck confirmed 2.8 cm lobular mass suggestive of paraganglioma. Metastatic work up was negative. Patient was referred for genetic testing considering young age and to rule out hereditary disorders. Interim, patient presented to the ED with complain of sudden onset lumbar backache without sphincteric involvement; neurological exam was unrevealing but on MRI lumbar spine found to have a 5.7×4.8×4cm lobulated well-circumscribed homogeneous soft tissue mass suggestive of schwannoma. Cervical and thoracic spine imaging was unremarkable. MRI brain showed a 1.1cm enhancing mass in right Meckel cave suggestive of meningioma.PET-DOTATATE scan was performed that revealed left neck mass as intensely avid, Right petrous apex mass as moderately avid and lumbar mass as not avid at all, consistent with the diagnosis of paraganglionoma, meningioma and schwannoma respectively. No evidence of DOTATATE avid nodal/ distant metastatic disease was found. Initially a hereditary etiology was suspected but genetic testing including (VHL, NF1/2, SDHD, SDHB) came back negative. Case was discussed with multidisciplinary teams; Neurosurgery service recommends conservative management of both meningioma and schwannoma at the moment considering benign course. Regarding paraganglioma, as tumor is non-secretory on repeated work up; sympathetic blockade is not warranted and patient is scheduled for pre-op embolization and surgical resection by Head and Neck surgery. Conclusion Paraganglionomas are generally benign non-secretory tumors that usually occur with other neuroendocrine tumors both as hereditary syndromes and sporadic cases. But their association with non-neuroendocrine tumors is mere incidental or has a genetic causation; is still unclear and warrants further research. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PSUN382 Hold Still – A Large Neck Paraganglioma Limiting Head Movement

Abstract Background A head and neck paraganglioma is a rare diagnosis with most cases found incidentally or diagnosed due to mass effect symptoms. Only 3.5% of them are found to secrete catecholamines leading to episodic symptoms. Herein, we present a rare case of a functioning neck paraganglioma with head movement induced hyperadrenergic paroxysms. Clinical Case A 79-year-old Caucasian man, with previous left neck mass found incidentally on imaging after a motor vehicle accident, presented to the ER with syncope. While the mass had been growing for 10 years, he sought medical attention when he could no longer turn his head to the left due to worsening symptoms. He reported recurrent brief syncopal attacks along with intermittent episodes characterized by profuse sweating, headaches, palpitations, and flushed skin. Upon evaluation, he was afebrile, tachycardic and had labile blood pressure readings (high of 340/150 mmHg and a low of 70/40 mmHg). He was oriented to time and place but appeared lethargic and underweight. A solid non-tender neck mass, with an audible bruit, was apparent at the Level II of the left neck. A CT scan of the neck showed a 7.7cm left glomus vagale tumor with partial encasement of the left internal and external carotid artery. He was admitted to the intensive care unit for close blood pressure monitoring via an intra-arterial line. Due to high suspicion for a catecholamine driven process, he was started on Doxazosin 1 mg every 12 hours which stabilized his blood pressure and improved his symptoms. CT scan of the abdomen and pelvis showed a 1.1 cm left adrenal nodule with an intensity of 4 Hounsfield units. A trial of Hyoscyamine was done to help with hypotension and symptoms of dizziness and bradycardia. Labs showed plasma catecholamines that were significantly elevated to ten times the upper limit of normal. An MIBG scan showed uptake in the left carotid mass. He was a poor surgical candidate because of the proximity of the mass to the neuro-vascular bundle and was treated with radiation during hospitalization. The patient was discharged home on Doxazosin with improvement in his blood pressure. Genetic testing was negative for a pathogenic variant but detected a variant of uncertain significance (VUS) in CDKN2A, c.373G>C (p.Asp125His). Unfortunately, three months later the patient was admitted with an intracranial hemorrhage secondary to a fall and was transitioned to hospice care. There was no change in the tumor size noticed during that admission. Conclusion To our knowledge, this is the first case to describe hypertension paroxysms triggered by movements of the neck in the setting of a functional neck paraganglioma. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.