Nonfunctioning Tumors Research Articles

Radiation therapy in functioning and no functioning pituitary neuroendocrine tumor: systematic review of the recent literature after 2011

SummaryNeuroendocrine pituitary tumor, a benign cells proliferation, can cause significant morbidity due to its local invasiveness and secretory properties. Historically, radiotherapy has been employed as a second or third-line treatment option, with studies dating back to the mid-20th century. However, advancements in radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), stereotactic radiosurgery, and proton therapy, have revolutionized treatment approaches. This review aims to critically evaluate the recent literature (2011–2022) on the use of radiotherapy in both functioning and nonfunctioning neuroendocrine pituitary tumor. We employed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology to systematically analyze 52 articles, focusing on local and hormonal control, radiotherapy protocols, and treatment-related side effects.

Preoperative Prediction of Lymph Node Metastases in Nonfunctional Pancreatic Neuroendocrine Tumors Using a Combined CT Radiomics-Clinical Model.

PanNETs are a rare group of pancreatic tumors that display heterogeneous histopathological and clinical behavior. Nodal disease has been established as one of the strongest predictors of patient outcomes in PanNETs. Lack of accurate preoperative assessment of nodal disease is a major limitation in the management of these patients, in particular those with small (< 2cm) low-grade tumors. The aim of the study was to evaluate the ability of radiomic features (RF) to preoperatively predict the presence of nodal disease in pancreatic neuroendocrine tumors (PanNETs). An institutional database was used to identify patients with nonfunctional PanNETs undergoing resection. Pancreas protocol computed tomography was obtained, manually segmented, and RF were extracted. These were analyzed using the minimum redundancy maximum relevance analysis for hierarchical feature selection. Youden index was used to identify the optimal cutoff for predicting nodal disease. A random forest prediction model was trained using RF and clinicopathological characteristics and validated internally. Of the 320 patients included in the study, 92 (28.8%) had nodal disease based on histopathological assessment of the surgical specimen. A radiomic signature based on ten selected RF was developed. Clinicopathological characteristics predictive of nodal disease included tumor grade and size. Upon internal validation the combined radiomics and clinical feature model demonstrated adequate performance (AUC 0.80) in identifying nodal disease. The model accurately identified nodal disease in 85% of patients with small tumors (< 2cm). Non-invasive preoperative assessment of nodal disease using RF and clinicopathological characteristics is feasible.

Pituitary neuroendocrine tumors treated with stereotactic radiosurgery.

Pituitary neuroendocrine tumors (pitNETs) are benign tumors that may recur after surgical resection or persist following medical management. The objective of this study was to evaluate outcomes and toxicities of patients with pitNETs treated with stereotactic radiosurgery (SRS) at a single institution. We completed a retrospective, single-institution study of patients with pitNETs treated with frame-based, single-fraction, cobalt-60 SRS between September 2005 and June 2023. The primary endpoint was local tumor control. Secondary endpoints included endocrine control (for functional tumors), overall survival, and toxicities. A total of 88 lesions in 83 patients were treated with SRS. Most lesions (70%) were non-functional tumors. Of the 26 functioning tumors, 6 patients achieved endocrine remission with SRS alone (23%), and the remainder achieved remission with combined medical management. With a median patient follow-up of 4.7 years, no local tumor recurrences were observed with an estimated local control probability of 100%. Two- and five-year overall survival estimates were 97% (95% confidence interval [CI] 89-99) and 95% (95% CI 84-98), respectively. Causes of death were unrelated to PitNET or SRS. Twelve patients (14%) developed hypopituitarism after SRS. Despite the 34 lesions that were ≤ 3mm from optic structures, no patients developed any optic neuropathy or visual decline post SRS. SRS is a highly effective modality for recurrent or residual pitNETs. This study observed a local control of 100% with no cases of optic toxicities after a median follow-up of 4.7 years. These observed findings suggest that dose de-escalation may be possible for future treatment of pitNETs.

Sinonasal Outcomes after Endoscopic Pituitary Surgery in Patients With Cushing's Disease.

The endoscopic endonasal approach (EEA) has become the preferred treatment for pituitary tumors, with minimal sinonasal morbidity. However, patients with Cushing's disease (CD) may represent a subgroup with prolonged impairment of sinonasal quality of life (QOL). We retrospectively identified patients with CD who underwent EEA at our institution. Control patients with non-functional tumors were matched by age, gender, and extent of EEA. The primary outcome was post-operative 22-item Sino-Nasal Outcome Test (SNOT-22) scores. Ten patients with CD met the selection criteria and 20 controls were selected for comparison. Nine of the CD patients achieved persistent endocrinologic remission post-operatively. Comparing the CD and control groups, there was no difference in post-operative SNOT-22 score at 1 or 3 months. At 6 months, SNOT-22 scores were significantly worse in the CD group (27.4 ± 21.6 vs. 2.8 ± 2.3, P = .039). SNOT-22 scores improved to normal from 1 to 6 months in the control cohort (P = .007), but not in the Cushing's group (P = .726). Morbidity was present across all SNOT-22 domains, but was highest in the sleep domain (P = .023). Only morbidity in the facial domain improved over time (P = .032). Patients with CD have significantly prolonged postoperative sinonasal QOL impairment following EEA compared to patients with non-functioning tumors, who normalize within 6 months. In CD patients, only morbidity in the facial domain, likely related to post-operative pain and nasal packing, improved over time, while the sleep domain was the most affected.

Immunohistochemical expression of CYP11A1, CYP11B, CYP17, and HSD3B2 in functional and nonfunctional canine adrenocortical tumors.

Functionality of human adrenal tumors is inferred by CYP11B1 (cortisol synthase) expression, CYP11B2 (aldosterone synthase) expression, or both. Nonfunctional canine adrenal tumors have low expression of steroidogenic enzymes, whereas aldosterone-producing tumors express CYP11B, and cortisol-producing tumors express both CYP11B and CYP17. Twenty-two client-owned dogs with adrenocortical tumors (ACT) (8 nonfunctional, 7-cortisol producing, 2 aldosterone-producing and 5 functional noncortisol producing) and 2 dogs with normal adrenal glands. Retrospective case series. Adrenal functionality was determined from clinical signs and endocrine testing. CYP11A1, CYP11B, CYP17, and HSD3B2 expression was detected by immunohistochemistry on formalin-fixed paraffin-embedded adrenal tissue. Protein expression was semiquantified by 2 blinded observers using H-scoring (results reported as median [range]) and compared in nonfunctional and cortisol-producing adrenal tumors by Mann-Whitney U tests. CYP11A1, CYP11B, and HSD3B2 were present within all cortical layers of normal adrenal glands, and CYP17 was expressed within the zona fasciculata and zona reticularis. Expression of CYP11A1 (191.25 [97.5-270] vs. 175 [102.5-295] P = .69), CYP11B (190 [130-265] vs. 147.5 [95-202.5]; P = .07), CYP17 (177.5 [87.5-240] vs. 247.5 [55-292.5]; P = .40), and HSD3B2 (230 [47.5-295] vs. 277.5 [67.5-295]; P = .34) were not significantly different between cortisol-producing and nonfunctional ACT. Our findings suggest it is not possible to determine functionality of canine ACT by immunohistochemistry for steroidogenic enzymes. Tumor size cannot be used to infer functionality of adrenal tumors.

Preoperative Glycosylated Hemoglobin A1C Impacts Long-Term Outcomes Following Curative-Intent Resection of Nonfunctional Gastroenteropancreatic Neuroendocrine Tumors.

To investigate the impact of preoperative glycosylated hemoglobin A1C (HbA1c) among patients following curative-intent resection of nonfunctional gastroentropancreatic neuroendocrine tumors (GEP-NETs). Patients who underwent curative-intent resection for GEP-NETs from 2000 to 2020 were identified from the US Neuroendocrine Tumor Study Group (US-NETSG). Preoperative blood HbA1c levels were defined as high HbA1c (≥ 6.5%) versus low HbA1c group (< 6.5%). Impact of HbA1c level on postoperative short-term and long-term overall (OS) were investigated. A total of 130 patients with HbA1c < 6.5% and 60 patients with HbA1c ≥ 6.5% were included. Patients with HbA1c ≥ 6.5% had higher proportion of comorbidities, such as hypertension, obesity, anemia, and lower preoperative albumin levels versus patients with HbA1c < 6.5% (all p < 0.05). In addition, high level of preoperative HbA1c was associated with increased incidence of wound and infectious complications, as well as decreased long-term OS (median OS: high Hb1Ac 89.8 months vs. low Hb1Ac not reached, HR 3.487, p = 0.004) among patients with nonfunctional GEP-NETs, as well as among the subset of pancreatic NET patients (median OS: high Hb1Ac 74.3 months vs. low Hb1Ac not reached, p = 0.004), and patients with normal fasting blood glucose (< 140 mg/dL) (median OS: high Hb1Ac 75.4 months vs. low Hb1Ac not reached, p = 0.001). Hb1Ac might have value as a screening tool to identify high-risk patients following surgical resection of nonfunctional GEP-NETs for consideration of more strict postoperative surveillance and treatment of elevated Hb1Ac level.

8801 Towards Safe and Efficacious Medical Therapy for Patients with Clinically Non-Functioning Pituitary Tumors

Abstract Disclosure: D. Zhang: None. M. Bergsneider: None. W. Kim: None. M.B. Wang: None. H. Vinters: None. A.P. Heaney: None. Clinically non-functioning pituitary tumors (CNFTs) account for one-third of all pituitary adenomas. They do not cause clinical and/or biochemical evidence of tumor-related hormone hypersecretion, grow insidiously and typically present with mass effect symptoms such as headache and visual field deficits. Surgical resection is the current standard of care for CNFTs but complete resection is infrequently achieved due to their size and invariable invasion of locally adjacent structures. CNFT remnant tumor regrowth rates approach 50% and these patients may need repeat surgery and/or radiotherapy (RT). The latter is quite effective in achieving tumor control, but carries a risk of hypopituitarism of ∼ 40% at 10 years. Although dopamine agonists and somatostatin receptor ligands have been explored as medical therapy, there are currently no consistently effective medical treatments for CNFTs. There is a clear unmet need for novel safe and effective medical therapies for these comparatively common tumors. In a highly innovative approach we have used patient-derived ex vivo 3D tumoroid human CNFTs in an automated high throughput compound screen (HTS) to identify novel tumoricidal and growth inhibitory compounds for CNFTs. To date, we have screened ∼4,000 compounds and have identified 13 potential hits that inhibited tumor cell proliferation (a reduction of 76±15%) and induced apoptosis (induction rate of 8.2 ± 6.6) in the CNFT tumoroids respectively. The hit compounds to date fall into 3 categories based on their targets, namely Na+/K+-ATPase inhibitors (n=6), reactive oxygen species (ROS) regulators (n=4), and cell cycle inhibitors (n=3). Representative “hit” compounds from each group identified in our primary screen were rescreened in triplicate in 20 concentrations from 25µM to 50pM at 2-fold dilutions. Dose-response curves characterized compound doses that inhibited cell viability by 50% (IC50) and ranged from 13nM to 103nM. Two of these 3 compounds also induced 2-3-fold apoptosis at 0.1uM with the final compound displaying a potent 5-10-fold pro-apoptotic effect at 0.15uM concentration. In parallel, we used single cell RNA sequencing to validate targets that emerged from our HTS and to characterize the mechanism of action (MOA) of these hit compounds. As proof of concept, several of the known drug targets were noted to be amongst the highest differentially expressed genes in the CNFT tumor cell population. This approach validating a candidate target in conjunction with demonstrable activity of a drug for that same target in CNFTs may simultaneously provide us with a back-bone molecule to further develop with structural activity relationship analysis and/or allow us to individualize drug choice in patients based on immunocytochemical tumor target expression. Presentation: 6/1/2024

6743 Decline in IGF-1 after surgery of the nonfunctioning pituitary neuroendocrine tumor

Abstract Disclosure: J. Sugata: None. S. Fujio: None. R. Makino: None. T. Hanada: None. R. Hanaya: None. Background: Patients undergoing surgical treatment for nonfunctioning pituitary neuroendocrine tumors (PitNET) may experience impaired secretion of growth hormone (GH). The optimal timing for assessing GH secretory function postoperatively remains unclear. In our department, we typically conduct hormone-loading tests three months after surgery. However, even in some cases without a diagnosis of growth hormone deficiency (GHD) at that point, there might be a gradual decline in Insulin-like growth factor-1 (IGF-1). Methods: We studied patients who exhibited peak GH levels &amp;gt; 1.8ng/ml in an insulin tolerance test (ITT) three months after undergoing surgery for nonfunctioning PitNET. We evaluated the levels of IGF-1 during the last observation, excluding cases where reoperation or radiosurgery was performed. Results: We identified 67 cases (29 males, 38 females) meeting the study criteria, with a median age of 54 years. The median follow-up time spanned 6 years (range 1-13 years). The median standard deviation (SD) scores of IGF-1 three months after surgery were -0.96, with 14 cases (21%) below -2.0 SD. At the end of the follow-up period, the median SD scores of IGF-1 were -1.31. This was significantly lower than the three-month time point (p&amp;lt;0.01), and 21 cases (31%) recorded were below -2.0 SD. In 6 cases suspected of severe GHD due to subjective symptoms or decreased IGF-1, ITT, or GH-releasing peptide-2 were retested. Among these, 2 cases were diagnosed with severe GHD, while the remaining demonstrated normal secretion of GH despite the low concentration of IGF-1. The IGF-1 SD scores at the end of follow-up and the three-month time-point exhibited a significant correlation (R2=0.74, p&amp;lt;0.01). However, no correlation was found between IGF-1 scores and peak GH concentration, age, tumor size, pituitary apoplexy, or preoperative IGF-1 SD scores. Conclusions: IGF-1 exhibited a progressive decrease in the majority of cases without severe GHD, with some cases showing reductions greater than -2.0 SD. Our findings emphasize the importance of cases with long-term clinical follow-up low IGF-1 after PitNET surgery, even when GH secretion appears normal. Presentation: 6/1/2024

7446 Primary Adrenal Mature Teratoma Initially Diagnosed As An Adrenal Myelolipoma

Abstract Disclosure: A. White-Cotsmire: None. B. Kodali: None. A.M. Avram: None. S.S. Shah: None. Background: Teratomas are a type of germ cell tumor containing different types of tissue (e.g., hair, teeth, bone adipose, muscle). Most teratomas are benign (i.e., mature), but they may also be malignant (i.e., immature). Both immature and mature teratomas contain derivatives of ectoderm, endoderm, and mesoderm; however, immature teratomas are differentiated by the presence of embryonic, usually neuroectodermal, tissue. Mature teratomas have the potential for malignant transformation (1–2% of cases), usually squamous cell carcinoma within the teratoma. Extra-gonadal teratomas are rare (only 1–5%); reported locations include sacrococcygeal, head and neck, retroperitoneum, mediastinum, brain and spine, liver, and rarely adrenal glands. (1) Only 18 cases of adult primary adrenal teratomas have been reported since 1952. (2)Clinical Case: A 48-year-old woman with 4 days of worsening abdominal pain underwent CT imaging, which demonstrated a 6cm complex left adrenal mass containing peripheral and scattered internal-coarse calcifications with internal soft tissue and fat components, suggestive of adrenal myelolipoma with probable sequela of previous hemorrhage. Subsequent endocrine follow-up ruled out a cortisol secreting tumor with a negative dexamethasone suppression test and pheochromocytoma with normal serum free metanephrines and normetanephrines. Dedicated adrenal protocol CT scan further characterized the mass as a mature adrenal teratoma containing a rudimentary mandible and two teeth within the soft tissue associated with internal microscopic fat. The left renal vein was anteriorly displaced by this left adrenal mass and severely narrowed by the large adrenal mass, with development of left retroperitoneal collateral venous drainage from the left kidney into the lumbar venous system. The patient opted for conservative management with active clinical surveillance. Conclusion: This is a rare case of adrenal mature teratoma in an adult, originally diagnosed as an adrenal myelolipoma. This case highlights the use of more dedicated adrenal imaging for the characterization of adrenal tumors and the broad differential of benign non-functional adrenal tumors, including myelolipomas, lipomas, angiomyolipomas, and nonfunctional adenomas. However, a definitive diagnosis can only be confirmed by surgical removal of the tumor, usually through a laparoscopic approach, with histopathologic evaluation.

8789 Unraveling Von Hippel Lindau Syndrome: A Comprehensive Analysis of Clinical Manifestations, Age-Related Variations, and Tumor Prevalence in a Specialized Endocrine Center

Abstract Disclosure: K.K. Pasam: None. Y. Gupta: None. A. Goyal: None. N. Tandon: None. Introduction: This study presents a thorough examination of Von Hippel Lindau (VHL) syndromes, focusing on the clinical spectrum and genetic mutations in our population. Methods: The study, conducted at the Department of Endocrinology and Metabolism from 2016 to 2022. Objectives included studying the spectrum of diseases in index patients and asymptomatic family members. Results: In our study, we identified 19 index cases and 12 asymptomatic cases identified on screening. The analysis of 31 VHL patients revealed a mean age of presentation of 24.2±11.1 years. Pancreatic cysts were the most common manifestation in 61% followed by pheochromocytoma in 54%, cerebellar hemangioblastomas in 45%, retinal angiomas in 39% and renal cell carcinoma in 35%. 16% of patients presented with nonfunctioning pancreatic neuroendocrine tumors, and one case featured an endolymphatic sac tumor.Pheochromocytomas in VHL syndrome presented at a remarkably young age, with an average of 23.1±11.4 years. Bilateral pheochromocytomas were observed in 14 (82%) and hormonal evaluation revealed urinary noradrenaline, normetanephrines, and plasma normetanephrine elevations of 5, 6, and 7-fold, respectively.The median size of pheochromocytomas in VHL syndrome was 5.4 cm. Metastatic pheochromocytoma was observed in one patient. Genetic analysis was available for 9 patients with most common mutation in exon 3 of chromosome 3. Discussion:The average age of VHL syndrome presentation in our cohort is younger than in other Indian studies. Males in our study were 45%, deviating from the absence of gender preponderance associated with VHL. Disparities in age of diagnosis and tumor prevalence compared with other international cohorts highlight potential regional and ethnic variations. Multiple pancreatic cysts in our study, with a prevalence of 61%, lower than the South Indian study's 71%. Literature comparisons indicate pancreatic cyst prevalence ranging from 42% to 51.6%. Cerebellar hemangioblastomas and retinal angiomas, typical VHL lesions, displayed prevalence rates of 45% and 39%, respectively.Pheochromocytoma, the second most common tumor in our cohort (54%), exhibited variations in prevalence compared to international studies. Higher rates reported by Fagundes et al. and Dwivedi et al. from Brazil might be attributed to recruitment biases from endocrine centers.The average age of VHL-associated pheochromocytoma presentation in our study contrasts with MEN2, emphasizing the unique features of VHL. Our study, reporting a 16% prevalence of PNETs, aligns with Binderup et al. The mean age of presentation for VHL-associated PNETs (20.8 ± 3.63 years) contrasts with Western literature, suggesting potential ethnic differences. Conclusion: Our study contributes to a nuanced understanding of VHL syndrome, shedding light on age-related variations, gender distribution, and tumor prevalence. Presentation: 6/2/2024

6672 Pituicytomas and Spindle Cell Oncocytomas: Rare Posterior Pituitary Tumors

Abstract Disclosure: Y. Park: None. A. Shen: None. M. Christie: None. J. Wentworth: None. C.J. Yates: None. J. King: None. Background: Pituicytomas and spindle cell oncocytomas (SCO) are rare non-functioning benign posterior pituitary tumors that can present as suprasellar or sellar-suprasellar masses.[1] Pituicytomas originate from the pituicytes in the neurohypophysis and infundibulum of the pituitary gland.2 SCO were previously thought to derive from the adenohypophysis,3 however, are now classified as a tumor of the neurohypophysis characterized by immunohistochemical reactivity to thyroid transcription factor 1 (TTF1).4 According to the World Health Organization 2021 classifications, pituicytomas, granular cell tumors and SCO may represent morphologic variations of the same tumor expressing TTF1.5 Due to their rarity, their clinical characteristics are not yet well-defined and can be mistaken as non-functioning pituitary adenomas. Methods: We retrospectively reviewed the clinical data of two patients with pituicytomas and two patients with SCO confirmed on histopathology at our institution, evaluating their clinical characteristics and management outcomes. Results: Two male patients, aged 59 and 79, were diagnosed with pituicytoma, and two male patients, aged 33 and 55 were diagnosed with SCO. Three presented with visual impairment from mass effects and three patients had hypogonadotropic hypogonadism. None had pre-operative arginine vasopressin (AVP) deficiency. All lesions were isointense on T1-weighted, and most were hyperintense on T2-weighted magnetic resonance imaging. Three cases had non-gross total resection due to hypervascularity. Postoperatively, two patients developed AVP deficiency and three developed persistent anterior pituitary insufficiency (Table 1). Pituicytomas had a Ki67 of 1-3%, and SCO had a Topoisomerase labelling index of &amp;lt;1%. In one case of pituicytoma, due to tumor recurrence 2 years after initial surgery, adjuvant radiotherapy was considered. However, the patient developed a severe peri-tumoral subarachnoid hemorrhage and died prior to receiving radiotherapy. In contrast, the progression of the residual SCO occurred at a slower rate. Discussions: Posterior pituitary tumor differentials are broad, including pituicytoma, SCO, granular cell tumor, craniopharyngioma, meningioma and germinoma;6 hence, histopathological diagnosis is crucial. Although benign, pituicytomas and SCO can result in increased morbidity and postoperative complications, such as AVP deficiency and hypopituitarism. Recurrence and progression are common.7, 8 Gross total resection is optimal, but this is difficult due to hypervascularity.9 Our case of peri-tumoral subarachnoid hemorrhage resulting in death emphasizes the hypervascular nature of pituicytomas. Patients with pituicytomas and SCO should be monitored for tumor progression or recurrence and hemorrhagic complications. Adjuvant radiotherapy may be considered for the management of tumor recurrence. Presentation: 6/3/2024

8789 Unraveling Von Hippel Lindau Syndrome: A Comprehensive Analysis Of Clinical Manifestations, Age-Related Variations, And Tumor Prevalence In A Specialized Endocrine Center

Abstract Disclosure: K.K. Pasam: None. Y. Gupta: None. A. Goyal: None. N. Tandon: None. Introduction: This study presents a thorough examination of Von Hippel Lindau (VHL) syndromes, focusing on the clinical spectrum and genetic mutations in our population. Methods: The study, conducted at the Department of Endocrinology and Metabolism from 2016 to 2022. Objectives included studying the spectrum of diseases in index patients and asymptomatic family members. Results: In our study, we identified 19 index cases and 12 asymptomatic cases identified on screening. The analysis of 31 VHL patients revealed a mean age of presentation of 24.2±11.1 years. Pancreatic cysts were the most common manifestation in 61% followed by pheochromocytoma in 54%, cerebellar hemangioblastomas in 45%, retinal angiomas in 39% and renal cell carcinoma in 35%. 16% of patients presented with nonfunctioning pancreatic neuroendocrine tumors, and one case featured an endolymphatic sac tumor.Pheochromocytomas in VHL syndrome presented at a remarkably young age, with an average of 23.1±11.4 years. Bilateral pheochromocytomas were observed in 14 (82%) and hormonal evaluation revealed urinary noradrenaline, normetanephrines, and plasma normetanephrine elevations of 5, 6, and 7-fold, respectively.The median size of pheochromocytomas in VHL syndrome was 5.4 cm. Metastatic pheochromocytoma was observed in one patient. Genetic analysis was available for 9 patients with most common mutation in exon 3 of chromosome 3. Discussion:The average age of VHL syndrome presentation in our cohort is younger than in other Indian studies. Males in our study were 45%, deviating from the absence of gender preponderance associated with VHL. Disparities in age of diagnosis and tumor prevalence compared with other international cohorts highlight potential regional and ethnic variations. Multiple pancreatic cysts in our study, with a prevalence of 61%, lower than the South Indian study's 71%. Literature comparisons indicate pancreatic cyst prevalence ranging from 42% to 51.6%. Cerebellar hemangioblastomas and retinal angiomas, typical VHL lesions, displayed prevalence rates of 45% and 39%, respectively.Pheochromocytoma, the second most common tumor in our cohort (54%), exhibited variations in prevalence compared to international studies. Higher rates reported by Fagundes et al. and Dwivedi et al. from Brazil might be attributed to recruitment biases from endocrine centers.The average age of VHL-associated pheochromocytoma presentation in our study contrasts with MEN2, emphasizing the unique features of VHL. Our study, reporting a 16% prevalence of PNETs, aligns with Binderup et al. The mean age of presentation for VHL-associated PNETs (20.8 ± 3.63 years) contrasts with Western literature, suggesting potential ethnic differences. Conclusion: Our study contributes to a nuanced understanding of VHL syndrome, shedding light on age-related variations, gender distribution, and tumor prevalence. Presentation: 6/2/2024

6485 Unilateral Adrenal Metastasis From Unknown Primary Carcinoma Mimicking Primary Adrenocortical Carcinoma

Abstract Disclosure: S. Watanabe: None. S. Suzuki: None. K. Ishiwata: None. Y. Yamazaki: None. H. Sasano: None. K. Yokote: None. Background: Adrenal metastasis from carcinomas of the lung, breast, and melanoma are observed. However, isolated adrenal metastasis with unknown primary carcinoma origin has been rare, and the diagnosis is challenging. We encountered a case of unilateral adrenal tumor clinically diagnosed as non-functional primary adrenocortical carcinoma, but found to be a metastatic tumor on postoperative pathology. Clinical Case: A 68-year-old man was referred to our hospital for examination of an 8mm right adrenal incidentaloma. He underwent hormone therapy for prostate cancer four years ago, and the condition is in remission with no recurrence signs. Follow-up CT revealed that the adrenal tumor rapidly enlarged from 8 mm to 36 mm within six months, and its mean attenuation value was 38 HU. MRI showed that the adrenal tumor had a low signal intensity on T1 and a high signal on T2. At the same time, there is mediastinal lymphadenopathy and a 9-mm nodule in the lower lobe of the right lung, which was considered benign from the stable condition. FDG-PET/CT showed FDG uptake only in the right adrenal tumor (maximum standardized uptake value of 21.39). [1]23I-MIBG scintigraphy did not show any accumulations. The serum and urinary adrenal hormones were all within normal limits. Notably, tumor markers such as prostate-specific antigen (PSA), carcinoembryonic antigen (CEA), α-fetoprotein (AFP), and cancer antigen 19-9 (CA 19-9) were all within normal ranges. Therefore, we clinically suspected non-functional primary adrenocortical carcinoma, and the laparoscopic right adrenalectomy was performed. The resected right adrenal lesion was encapsulated and measured 79×54×22 mm. On histological analysis, the nodule comprised tumor cells with eosinophilic cytoplasm, and abundant tissue infiltrating lymphocytes. Immunohistochemical studies revealed that the tumor was not of adrenal origin due to negative steroidogenic factor-1 (SF-1) and inhibin alpha staining. From these results, the adrenal tumor was diagnosed as adrenal metastasis from unknown primary carcinoma. The tumor cells were positive for cytokeratin19, CEA, and thyroid transcription factor-1 but negative for PSA, p63, cytokeratin 5/6, insulinoma-associated protein-1, and synaptophysin. Genetically, the adrenal tumor harbored genomic abnormalities in CDKN2A, TP53, NF1, PBRM1, and KEAP1 genes. Conclusion: Isolated adrenal metastasis without a detectable primary tumor is rare but should be considered a differential diagnosis in the case of an enlarged, non-functioning adrenal tumor. Adrenalectomy or tumor biopsy may be actively considered to diagnose and determine the optimal course of treatment. Presentation: 6/3/2024

The outcomes of robotic-assisted enucleation for tumors located in uncinate process of pancreas in 16 cases

Objective: To summarize the experience of robot-assisted enucleation of tumors located in uncinate process of pancreas. Methods: This is a retrospective case series study. The clinical data of patients with robot-assisted enucleation of tumors located in the uncinate process of pancreas at the Department of Gastroenterology and Pancreatic Surgery,Zhejiang Provincial People's Hospital from June 2019 to December 2023 were retrospectively analyzed. A total of 16 cases were enrolled,including 10 males and 6 females,with an age(M(IQR)) of 56(21)years (range: 28 to 77 years),and body mass index of 22.4(2.3)kg/m2 (range:19.8 to 25.6 kg/m2). Follow-up was asked every 6 to 12 months after the first 3-month postoperative follow-up through out-patient service or via telephone. Results: In total 16 cases,there were 11 cases with pancreatic enucleation,and 5 cases with resection of the uninate process. The operation time was 70(60) minutes (range: 40 to 165 minutes),and the blood loss was 30(13)ml (range: 10 to 80 ml). The rate of pancreatic fistula was 5/16. The length of stay was 8(6)days (range: 5 to 33 days). The pathological finding included non-functional neuroendocrine tumor(n=3),insulinoma(n=2),introductal papillary mucinous neoplasm (n=5),solid pseudopapillary neoplasm (n=2),mucinous cystadenoma (n=1),serous cystadenoma (n=2),pseudocyst (n=1). Follow-up as of March 12, 2024, the follow-up time was 16(12)months (range: 3 to 41 months). All patients had no new onset diabetes and no dyspepsia. Conclusion: Robot-assisted surgical system can be used for local resection of uncinate process tumors of pancreas,and the quality of life of patients can be improved.

S2470 Diagnosis of Non-Functional Pancreatic Neuroendocrine Tumor in a Patient with a Transplanted Pancreas: A Case Report

S2470 Diagnosis of Non-Functional Pancreatic Neuroendocrine Tumor in a Patient with a Transplanted Pancreas: A Case Report

The Spectrum of Adrenal Lesions in a Tertiary Referral Center.

Adrenal tumors are a common finding in clinical practice, and only detailed evaluation may reveal secretory and metabolic abnormalities or their malignant character. We aimed to highlight epidemiological data, rates of malignancy, clinical or secretory characteristics, and the cardiometabolic implications of adrenal masses. We conducted a retrospective analysis using data from the medical files of 474 patients with adrenal pathology hospitalized between January 2007 and January 2020, before the COVID-19 pandemic, using the ICD-10 codes. After applying inclusion and exclusion criteria, a total of 264 patients with adrenal tumors were enrolled in the study. Patients underwent clinical examination, abdominal imaging, and hormonal evaluation, and some of them underwent a pathological exam after adrenalectomy. Median age at diagnosis was 56 (17) years, with 81.06% of patients being female. The median follow-up period was 41.5 (70) months, ranging from 6 months to 13 years. Adrenal tumors were most frequently seen in older female patients, with 83.47% of them being over 40 years old. The malignancy rate was 4.54%. Hormonally nonfunctioning tumors (71.95%) predominated, and overt hypercortisolism was present in 10.61% of patients, as was mild autonomous cortisol secretion in 5.31% of patients, primary hyperaldosteronism in 8.71% of patients, and adrenal paraganglioma in 3.41% of patients. Cardiometabolic comorbid conditions were similar in patients with functioning and nonfunctioning tumors. All patients with adrenal tumors should receive a complete hormonal workup and detailed malignancy risk assessment. Even though a hormonally active tumor predisposes to cardiometabolic comorbid conditions, a nonfunctioning lesion may also be associated with such disorders and needs thorough assessment.

Using transcriptomics to refine the subtypes of non-functioning pituitary neuroendocrine tumours

Using transcriptomics to refine the subtypes of non-functioning pituitary neuroendocrine tumours

Transformation of non-functioning pancreatic neuroendocrine tumours into insulinomas in multiple endocrine neoplasia type 1: a case report

Transformation of non-functioning pancreatic neuroendocrine tumours into insulinomas in multiple endocrine neoplasia type 1: a case report

An Uncommon Culprit: Pancreatic Neuroendocrine Tumor in a Patient with Uncontrolled Diabetes

Pancreatic Neuro Endocrine Tumors (NETs) are rare neoplasms that originate from the endocrine tissues of the pancreas, accounting for only 1-2% of pancreatic tumors. Despite their low incidence, these tumors present with a wide range of symptoms and have the ability to secrete hormones, posing significant challenges for their diagnosis and treatment. There are two distinct types of pancreatic NETs: functioning and nonfunctioning. Functioning tumors are characterized by hormone-related clinical syndromes, while nonfunctioning tumors are often found incidentally. The pathogenesis of pancreatic NETs involves both sporadic and hereditary factors, including syndromes such as MEN1, VHL, and NF1. Typically, these tumors are diagnosed in individuals between the ages of 40 and 60, and their effective management requires a multidisciplinary approach. Diagnostic imaging techniques, such as CT and EUS, play a crucial role in accurate diagnosis, while PET scans aid in staging and treatment planning. Histological analysis is essential for determining the tumor grade and predicting prognosis. Treatment strategies are tailored to the tumor's characteristics and the patient's overall health. These may include the use of somatostatin analogs, such as Lanreotide and Octreotide, to control hormone secretion and inhibit tumor growth, as well as systemic therapies like everolimus, sunitinib, and PRRT for metastatic disease. This case report describes the clinical course of a 66-year-old male with a well-differentiated pancreatic NET who initially presented with persistent hyperglycemia. Further investigations revealed a sizable pancreatic mass and liver metastases. Diagnostic evaluation confirmed a grade 1 Neuro Endocrine Tumor, and the patient was started on treatment with Lanreotide. However, his management was complicated by the development of hepatic encephalopathy, which necessitated treatment with lactulose and rifaximin. This case highlights the importance of considering pancreatic NETs in cases of atypical diabetes presentations and emphasizes the need for a multidisciplinary team to provide optimal care. Given the complex nature of pancreatic NETs, a comprehensive diagnostic workup and personalized treatment approach are essential for improving patient outcomes.

Neoadjuvant 177Lu-DOTATATE for non-functioning pancreatic neuroendocrine tumours (NEOLUPANET): multicentre phase II study.

Resection of non-functioning pancreatic neuroendocrine tumours (NF-PanNETs) is curative in most patients. The potential benefits of neoadjuvant treatments have, however, never been explored. The primary aim of this study was to evaluate the safety of neoadjuvant 177Lu-labelled DOTA0-octreotate (177Lu-DOTATATE) followed by surgery in patients with NF-PanNETs. NEOLUPANET was a multicentre, single-arm, phase II trial of patients with sporadic, resectable or potentially resectable NF-PanNETs at high-risk of recurrence; those with positive 68Ga-labelled DOTA PET were eligible. All patients were candidates for neoadjuvant 177Lu-DOTATATE followed by surgery. A sample size of 30 patients was calculated to test postoperative complication rates against predefined cut-offs. The primary endpoint was safety, reflected by postoperative morbidity and mortality within 90 days. Secondary endpoints included rate of objective radiological response and quality of life. From March 2020 to February 2023, 31 patients were enrolled, of whom 26 completed 4 cycles of 177Lu-DOTATATE. A partial radiological response was observed in 18 of 31 patients, and 13 patients had stable disease. Disease progression was not observed. Twenty-four R0 resections and 4 R1 resections were performed in 29 patients who underwent surgery. One tumour was unresectable owing to vascular involvement. There was no postoperative death. Postoperative complications occurred in 21 of 29 patients. Severe complications were observed in seven patients. Quality of life remained stable after 177Lu-DOTATATE and decreased after surgery. Neoadjuvant treatment with 177Lu-DOTATATE is safe and effective for patients with NF-PanNETs.