Well-differentiated Tumors Research Articles

THU527 Metastatic Adenocarcinoma Of The Colon Concealing An ACTH Secreting Neuroendocrine Differentiated Cluster: A Lethal Zebra Within A Trojan Horse

Abstract Disclosure: M. Velasquez: None. S. Shekhar: None. R.M. Goyal: None. Background: Ectopic ACTH secreting tumors are responsible for almost 10% of all cases of Cushing Syndrome. Tumors associated with this entity are most commonly small cell lung, thymic, and pancreatic neuroendocrine tumors. Few cases of colon adenocarcinoma with paraneoplastic ACTH secretion have been reported. They are associated with poor outcomes. Clinical case: A 57-year-old previously healthy male presented with shortness of breath and hypertension. CTA of the chest revealed metastatic liver lesions. CT abdomen and pelvis confirmed metastatic liver lesions with an apple core colonic mass consistent with a primary malignancy. Liver biopsy showed well-differentiated neuroendocrine tumor; tumor cells were negative for CK20, chromogranin, and CD56 but positive for CK7 and synaptophysin. The Ki-67 index was 30%. He was not evaluated for paraneoplastic hormonal secretion and the colonic mass wasn’t biopsied at that time. Ga-DOTATATE scan was negative for somatostatin uptake. He was started on carboplatin-etoposide + dexamethasone (three doses of 4mg each). Two months later presented with large bowel obstruction. Colonoscopy was performed and histopathology demonstrated colonic adenocarcinoma with focal neuroendocrine differentiation with positive CDX2 and negative CK7 and CK20. Synaptophysin was diffusely positive with sparse chromogranin positivity. ACTH stain of the colonic biopsy was negative. Chemotherapy was switched to FOLFORINOX and dexamethasone (one dose of 12mg). After two weeks of being on this regimen, he developed refractory hypokalemia and metabolic alkalosis and was sent to the emergency department. Vitals signs were within normal limits except for mildly elevated blood pressure. Physical examination remarkable for redness of his truncal skin. He did have changes in his handwriting, 0/3 three-word recall, and reduced short term memory. Primary team performed a morning cortisol that was elevated, and endocrinology was consulted. Two repeated 8AM cortisol level and a serum ACTH were found to be elevated. An 8mg overnight dexamethasone suppression test revealed an increase in cortisol. MRI brain showed no evidence of intracranial abnormalities. Refractory hypokalemia due to ectopic ACTH-dependent Cushing syndrome was diagnosed warranting treatment with ketoconazole. Unfortunately, he developed septic shock which led to his demise. Conclusion: This case illustrates a paradoxical rise in serum cortisol levels after dexamethasone suppression test suggesting the presence of positive feedback effects of exogenous corticosteroids on tumor’s ACTH release/production. Recognition of this syndrome is critical to avoid unnecessary use of exogenous glucocorticoids since they could trigger paraneoplastic Cushing syndrome in these patients. Presentation: Thursday, June 15, 2023

SAT148 A Rare Case Of Proinsulinoma In A Patient With Type 2 Diabetes Mellitus

Abstract Disclosure: E. Tirthani: None. F. Erenler: None. Background: A proinsulinoma is a very rare neuroendocrine tumor of the pancreas, which predominantly secretes proinsulin, the precursor hormone of insulin. Even though not as potent as insulin, proinsulin in higher amounts can bind to insulin receptors and result in hypoglycemia. Most patients present with initial hypoglycemia symptoms at the time of diagnosis of the tumor. The diagnosis becomes challenging in patients with underlying type 2 diabetes mellitus (T2DM) who may initially have a spontaneous remission of diabetes, followed by hypoglycemia episodes later in the disease course. Clinical Case: A 66-year-old man presented to our clinic in October 2020 with frequent episodes of dizziness and diaphoresis, which were relieved by eating food. The patient's symptoms began in 2018, occurred during the daytime, and were exacerbated by exercise. He had a past medical history of T2DM diagnosed in 2009 (HbA1c=10%) and treated with glipizide and metformin; however, over the years, his HbA1c improved, and glipizide was discontinued. By 2018 his HbA1c was down to 5.9%, and metformin was also stopped. The patient denied any change in his weight, diet, or exercise frequency during this time course. A fingerstick blood glucose (BG) checked during one of these episodes was 51 mg/dL. An abdominal CT scan in August 2020 revealed a 12x13 mm enhancing mass within the neck of the pancreas concerning for a neuroendocrine tumor. The patient was further evaluated with a 14-day continuous glucose monitor (CGM), which showed that the patient's BG was <70 mg/dL 31% of the time and <55 mg/dL 6% of the time. Additional fasting blood work showed a proinsulin level of 191.3 pmol/L (normal ≤18 pmol/L), insulin 15.5 uIU/mL (2-25 uIU/mL), BG 103mg/dL, C-peptide 2.44 ng/mL (0.80-3.85 ng/mL) and chromogranin A 124 ng/mL (25-140 ng/mL) which suggested the diagnosis of proinsulinoma. A Gallium-DOTATATE scan showed a localized tumor within the pancreas with no metastasis. The patient underwent enucleation of the tumor in November 2020. Pathology showed a well-differentiated neuroendocrine tumor staged T1 pN0 with immunohistochemistry staining diffusely positive for chromogranin, synaptophysin, and insulin with a Ki67 index <3%. In January 2021, at a post-surgery follow-up visit, blood work showed HbA1c 7.1%, proinsulin 31 pmol/L, insulin 13.4 uIU/mL, C-peptide 1.6 ng/mL, BG 193 mg/dl, and chromogranin A 118 ng/mL. HbA1c continued to trend up to 8.0% in January 2022, confirming the resurgence of diabetes, and metformin and pioglitazone were started. Conclusion: Per our literature review, this is the first reported case of a proinsulinoma in a patient with T2DM. In a patient with uncontrolled T2DM, an unexpected amelioration of the disease should raise concern for insulin-secreting tumors, and further workup should be considered. A CGM can be a valuable tool to assess the severity of hypoglycemia in patients with these tumors. Presentation: Saturday, June 17, 2023

FRI362 A Rare Case Of Coexisting Pancreatic Neuroendocrine Tumor And Nesidioblastosis

Abstract Disclosure: N. Mon: None. L.K. Tanwani: None. B. Martin: None. C. Scoggins: None. S.L. Mokshagundam: None. Introduction: Nesidioblastosis is a rare cause of endogenous hyperinsulinemic hypoglycemia in adult population. Pancreatic neuroendocrine tumors (NET) are also uncommon among pancreatic tumors. We report a case of a young man who presented with documented Whipple triad and was initially found to have pancreatic cyst. Further evaluation revealed concomitant pancreatic NET and adult nesidioblastosis. Case Report: A 36-year-old Caucasian male with history of anxiety, bipolar, and seizure disorder presented with witnessed seizures and was found to have blood glucose (BG) < 20 mg/dl. He reported recurrent hypoglycemia for 3 years with recent 4-5 ER visits for hypoglycemic seizures. Only medications he was taking were keppra and clonazepam. Physical exam was unremarkable. He was evaluated in Endocrine Clinic and a 72 Hour fast was performed. During the 72 hours fast his BG dropped to 48 mg/dl after 12 hrs. Insulin 16.1 uIU/mL, C peptide 3.02 ng/mL, Proinsulin 60.1 pmol/L, beta-hydroxybutyrate 0.08 mmol/l. BG increased to 116 mg/dl in 30 minutes after 1 mg glucagon injection. Other labs results were: 3PM cortisol 6.6 (7.0-25.0ug/dl), albumin 4.4 mg/dl, HbA1c 5.2%, Alcohol < 5ng/dl, negative urine toxicology screen. CT abdomen without contrast showed a 1.3 cm cyst in the tail of pancreas. Endoscopic ultrasonography revealed a round mixed solid and cystic mass (18x17 mm) with well-defined borders identified in the pancreas tail. The remainder of the pancreas was unremarkable. FNA of the cyst reported findings consistent with a well-differentiated neuroendocrine tumor. He underwent robotic enucleation of distal pancreatic lesion. Postoperative period was uneventful until 2 weeks after procedure when he again started having neuroglycopenic symptoms with lowest BG of 50 mg/dl in the fasting state. He was initiated on diazoxide 50 mg 3 times daily and then 100mg 3 times daily. He continued to have hypoglycemic episodes. Prednisone 10 mg was added at bedtime while waiting for surgery. He underwent distal 80 % pancreatectomy and splenectomy. Hypoglycemia resolved after the surgery. The final pathology was a well-differentiated NET WHO grade I with background neuroendocrine cell hyperplasia/nesidioblastosis. Conclusion: Endogenous hyperinsulinemic hypoglycemia is a rare disorder with nesidioblastosis being the important cause in children and insulinoma in adults, representing a spectrum of pathologic beta cell proliferation. There are very few reports of coexistence of both conditions in adults. Our patient also had an unusual type of insulinoma as it was cystic. The simultaneous occurrence of the two lesions offers significant challenges in diagnosis and management. The mainstay of treatment is surgical resection of insulinoma with localization of insulin hypersecretion; however, how much to remove in nesidioblastosis is still unclear. Presentation: Friday, June 16, 2023

THU014 Post-surgical Remission After Resection Of Solitary Mediastinal Lymph Node In A Metastatic Occult Ectopic ACTH Syndrome Patient

Abstract Disclosure: I.P. de Magalhães: None. C.P. Oliveira: None. L.P. Lins: None. N.X. Andrade: None. M.S. Lima: None. S.A. Siqueira: None. J.S. Fonini: None. E.C. Assis Filho: None. A.W. Mariani: None. M.C. Machado: None. BACKGROUND: The prevalence of occult cases has been increasing in the most recent series of Ectopic ACTH syndrome (EAS) maybe due to the small size of pulmonary neuroendocrine tumors. We present an atypical and very rare case of EAS with initial presentation of a single metastatic mediastinal lymph node that evolved with remission after your resection with no defined primary tumor. CASE REPORT: A 15-year-old female patient presented a clinical feature of Cushing’s syndrome (CS) with a 1-year evolution. Hormonal evaluation confirmed ACTH-dependent CS: urinary free cortisol of 819 µg/24h (3-43), late night salivary cortisol of 409 ng/dL (<274) and ACTH of 105 pg/mL (<63.3). Noninvasive methods for differential diagnosis of ACTH-dependent CS did not clarify the etiology (conflicting results): pituitary MRI negative, suppression of 59.6% of cortisol after high dose dexamethasone suppression test, positive response of ACTH and cortisol at desmopressin test, suppression of 81% of ACTH at acute octreotide SC test, negative serum tumor markers (gastrin, calcitonin, CEA, CA125, alpha-fetoprotein, CA19.9 and bhCG), negative cervical and pelvic ultrasound, negative computed tomography of thorax and negative abdominal MRI. Bilateral and simultaneous petrosal inferior sinus sampling with desmopressin confirmed EAS due to negative central to peripheral ACTH gradient, even after normalized PRL/ACTH gradients. Finally, PET/CT with Ga68-DOTATATE revealed a single infracarinal nodule of 1.5x0.6 cm with high capture of radioligand, SUVmax of 23.2, suggestive of affected mediastinal lymph node. The patient was submitted to thoracic surgery and the infracarinal lymph node was dissected and removed. Anatomopathological and immunohistochemical analyses disclosed a lymph node metastatic of a well-differentiated grade neuroendocrine tumor ACTH positive, Ki-67 2%. After surgery, the patient exhibited CS improvement and impressive drop of hormones at 5th postsurgical day (serum cortisol <1.0 µg/dL and ACTH of 2.2 pg/mL) confirming remission of CS. CONCLUSION: To our knowledge, approximately 36 cases of EAS due to neuroendocrine tumor of unknown primary origin were reported. However, previous cases commonly exhibited no remission after only removal of metastasis. Our case presented initial remission even with no primary tumor identified (occult primary tumor non-functioning?). Follow up with clinical, hormonal and imaging methods are necessary due to recurrence risk. Presentation: Thursday, June 15, 2023

FRI603 Treatment Of Severe Refractory Hypoglycemia Due To Malignant Insulinoma With A Novel Anti-insulin Receptor Antibody

Abstract Disclosure: S. Osataphan: None. M. Vamvini: None. E.D. Rosen: Consulting Fee; Self; Novartis Pharmaceuticals. L. Pei: None. N. Erlikh: None. G. Singh: None. P. Dhorajiya: None. J. Parker: None. J.M. Dreyfuss: None. A. Rattani: Stock Owner; Self; Vertex Pharmaceuticals, Provention Bio, Bluebird Bio, Agenus, MacroGenics, Immunity Bio, Mirati Therapeutics, Actinium Pharmaceuticals, Bausch Health Companies, Compass Therapeutics, Magenta Therapeutics. M. Patti: Advisory Board Member; Self; Fractyl Laboratories. Consulting Fee; Self; AstraZeneca, Hanmi Pharmaceuticals, MBX. Grant Recipient; Self; Dexcom. Severe hypoglycemia caused by malignant insulinoma is often resistant to medical therapy targeting both tumor burden and insulin secretion. We report a patient who developed severe, treatment-resistant hypoglycemia after receiving 177lutetium-DOTATATE (Lu-177). Hypoglycemia was completely ameliorated after treatment with RZ358, a human monoclonal antibody that functions as a negative allosteric modulator of the insulin receptor, reducing insulin signaling. This 55 year old man presented with abdominal pain, fatigue, and weight loss; imaging showed a 1.8 cm pancreatic tail mass and numerous hepatic lesions. Liver biopsy demonstrated well-differentiated pancreatic neuroendocrine tumor, WHO Grade 2, and pathogenic MEN1 mutation. Following one year of octreotide therapy, both pancreatic and hepatic tumors increased in size, prompting Lu-177 therapy. Two days after the first dose, the patient became unresponsive, with capillary glucose 20 mg/dL. He developed recurrent neuroglycopenia on day 8, with venous glucose 41 mg/dL, insulin 45 µIU/mL, C-peptide 6.5 ng/mL and proinsulin 453 pmol/L, requiring intensive care unit admission for for intravenous glucose. High-dose diazoxide, everolimus, dexamethasone, glucagon, pasireotide, or enteral feeding did not produce a response. Despite multiple therapies, neuroglycopenia required frequent dextrose boluses and continuous intravenous glucose (up to 30 g/hr of 50% dextrose); up to 58% of sensor glucose was below 70 mg/dL and 19% below 54 mg/dL over 24 hours. CT imaging 1 month after Lu-177 showed significant reduction in liver metastases size. Given the severity of hypoglycemia despite tumor regression, we considered treatment with RZ358, a human monoclonal antibody that acts as a negative allosteric modulator of the insulin receptor, inducing insulin resistance. We obtained emergency use authorization from the FDA, approval from the local Institutional Review Board, and written informed consent. Following a 6 mg/kg dose of RZ358, there was transient worsening of hypoglycemia accompanied by an 8-fold increase in insulin, potentially due to reduced insulin clearance. After dose increase to 9 mg/kg weekly, glucose infusion was weaned. Metabolic stability was achieved after 6 doses, allowing a second dose of Lu-177 and eventual discharge. Diazoxide was discontinued, steroid doses were reduced, and RZ358 dosing was reduced to every 3-4 weeks. A third dose of Lu-177 was administered without complications. Despite elevated insulin (537 uIU/mL), C-peptide (10.1 ng/mL), and proinsulin (634.0 pmol/L), he remains free of level 3 hypoglycemia. No adverse effects have been observed. In summary, the anti-insulin receptor monoclonal antibody RZ358 effectively controlled hypoglycemia refractory to multiple other therapies, allowing restoration of normoglycemia and enabling additional successful cancer therapy. Presentation: Friday, June 16, 2023

FRI360 A Protracted Course Of Worsening Adrenergic And Neuroglycopenic Symptoms Due To Delay In Diagnosis Of Insulinoma

Abstract Disclosure: A. Karca: None. W. Lai: None. S. Naidoo: None. L.N. Saladi: None. B.C. Jameson: None. A 33-year-old Hispanic male presented with altered mental status, witnessed seizure and hypoglycemia (capillary BG 40mg/dL). Patient and family reported multiple episodes of symptomatic hypoglycemia and progressively worsening adrenergic and neuroglycopenic episodes with altered mental status requiring hospital admissions and evaluation for endogenous hyperinsulinemia in the past several months prior to admission. Patient was admitted to the ICU. Laboratory workup revealed documented hypoglycemia (venous BG 45mg/dL) and inappropriate insulin (17uU/mL, n3-25uU/mL), c-peptide (2.7ng/mL, n0.8-4.2 ng/mL) and pro-insulin (38.3 pmol/L, n<18.8 pmol/L) levels. Sulfonylurea and meglitinide screens were negative. Patient required continuous dextrose infusion as well as octreotide, with enteral feeding, to maintain BG >70mg/dL. Abdominal US, multiple CT scans, endoscopic US failed to locate source of endogenous hyperinsulinemia. Multi-discipline discussion among ICU team, Endocrinology, Interventional Radiology (IR), and Surgery considered MRI versus IR-guided selective arterial calcium stimulation (SACS) vs PET-CT NETSPOT with Ga-68 Dotatate, which had been ordered, but unable to be arranged prior to this admission. Ultimately, MRI with pancreatic protocol revealed 3.5cm exophytic solid mass arising from the tail of the pancreas and patient underwent laparoscopic hand-assisted distal pancreatectomy and splenectomy, with intraoperative ultrasound to confirm the location of the mass. Histologic examination revealed a well-differentiated neuroendocrine tumor. Chart review revealed documented hypoglycemia as far back as eight years prior to this admission, although no further results were available from that time to confirm endogenous source. Possible explanations for delay in diagnosis include patient health literacy, inaccessibility of outpatient testing, limitations of testing modalities, and access to staff skilled in more specialized testing, like PET-CT NETSPOT and SACS. Localizing techniques are divided into pre-operative and intra-operative, with pre-operative techniques further divided into non-invasive and invasive modalities. First line pre-operative testing includes US and CT, which have widely varying sensitivity depending on size and location of the tumor. MRI can have better sensitivity for smaller and distal tumors. PET-CT NETSPOT with Ga-68 Dotatate, has very high sensitivity and specificity in limited studies. If not localized with non-invasive modalities, SACS is an invasive modality with high sensitivity and specificity. Although insulinomas are a rare neuroendocrine tumor with challenging diagnostic workup, higher clinical suspicion with early biochemical workup, patient education, referral to endocrinology, better accessibility of diagnostic testing will help lead to timely diagnosis and management. Presentation: Friday, June 16, 2023

THU484 Distinct Genetic Characteristics In Follicular Thyroid Cancer With Different Metastatic Potentials

Abstract Disclosure: S. Kwak: None. E. Lee: None. Y. Park: None. Although most follicular thyroid cancers (FTCs) show excellent prognosis, more than 5% accompany distant metastasis, often diagnosed unexpectedly in the advanced stage. Genetic or genomic markers have been shown to be useful as a prognostic tool in many cancers, but it is unclear whether genetic markers predicting the metastatic potential of FTCs exist. To investigate, 11 pairs of matched formalin fixed paraffin embedded tissue samples of primary (PTM1) and metastatic tumors (MT) from FTC patients with distant metastasis were analyzed by whole exome sequencing. For validation, 78 unmatched FTC samples including 49 well-differentiated tumors, 15 poorly-differentiated tumors and 14 anaplastic thyroid cancer (ATC) samples were analyzed by targeted sequencing. Among the 11 paired PTM1 and MT tumors, 10 showed concordant driver mutations (NRAS, HRAS, DICER1, EIF1AX), and the TERT promoter mutation was concordantly found in 6 pairs. However, the concordance rate of other somatic mutations in paired samples were found to be only 16.2%. Other mutational characteristics such as mutational signatures and CNVs also differed, suggesting the independent subclonal evolution of the paired MT from the PTM1 after metastasis. Interestingly, the frequency of mutations including driver, TERT promoter, and other mutations was lower in primary tumors without metastases (PTM0). Mutational characteristics of PTM0 also differed from those of PTM1 and MT, suggesting that the mutational or molecular characteristics of PTs at the time of diagnosis may distinguish metastatic potential. In a pooled analysis including published data of follicular patterned tumors, we found that metastatic or aggressive tumors were more likely to have the RAS mutation, which tended to be coupled with TERT, DICER1, EIF1AX, and TP53, gradually from minimally invasive FTC, widely invasive FTC to poorly differentiated thyroid cancer (PDTC) and ATC. Transcriptomic profiles from The Cancer Genome Atlas (TCGA) and our data (SNUH) showed RAS(+)/TERT(+) mutated tumors and RAS(+)/TERT(-) tumors had differences in several intracellular signal pathways. Therefore, when follicular neoplasm is diagnosed, NRAS and HRAS mutation tests followed by TERT promoter mutation tests may help diagnose FTCs with metastatic potential. Other genetic mutations could be candidates for a diagnostic or prognostic marker, and large-scale validation studies are warranted.This study was funded by the Basic Science Research Program through the National Research Foundation of Korea, funded by the Ministry of Science, ICT & Future Planning (NRF-2019R1A2C2084332). Presentation: Thursday, June 15, 2023

Expression of miR-141, TAMs, and CD147 in Bladder Cancer Cells: Implications for Tumor Grade and Prognosis

This study aimed to investigate the significance of miR-141 expression, tumor-associated macrophages (TAMs), and CD147 expression in bladder cancer (BCa) cells, and their relationship with tumor grade. A total of 80 BCa patients were selected, and they were categorized into two groups: Group G1 (56 cases) with poorly differentiated tumors, and Group G2 (24 cases) with moderately to well-differentiated tumors according to the WHO classification criteria for urothelial carcinoma. We analyzed the differences in miR-141, TAMs, and CD147 expression levels among different tumor grades. The miR-141 level in BCa tissues of patients in Group G2 showed a significant decrease (1.88±0.4) compared to Group G1 (P <0.05). As the tumor grade increased, TAMs levels in tumor tissues also increased (P <0.05). Notably, 66.7% of CD147-positive patients in Group G2 exhibited a clear increase compared to Group G1 (P <0.05). Importantly, significant correlations were observed between miR-141, TAMs, CD147 levels, and tumor grade (P <0.05). These findings suggest that as BCa grades increase, miR-141 levels decrease while TAMs and CD147 levels increase. The levels of miR-141, TAMs, and CD147 in BCa tissue cells can serve as indicators for evaluating the prognosis of BCa patients.

MDCT appearances of pancreatic insulinoma as well as the other well differentiated endocrine tumors

Introduction: Pancreatic endocrine tumors (PETs) are primarily well-differentiated tumors composed of cells that resemble normal islet cells but that arise from pancreatic ductal cells. They are classified as functioning or nonfunctioning according to their associated clinical symptoms; insulinomas, gastrinomas and glucagonomas are the most common function­ing PETs Case Report: A 36-years old man presented with a one-month history of fainting attacks and dizziness, symptoms of hypoglycemia such as hunger, sweating, palpitations, loss of consciousness and syncope. We tried abdominal enhanced spiral CT to localize the tumor, but that wasn’t successful. Therefore, we tried a new method of MD spiral CT scanning and localized the tumor. Discussion and Conclusion: Insulinomas are the commonest islet cell tumors of the pancreas, followed by gastrinomas. Preoperative localization is very helpful in planning the operation: it allows the surgeon to determine whether simple tumor resection or partial pancreatectomy is likely to be required.

Intertumoral lineage diversity and immunosuppressive transcriptional programs in well-differentiated gastroenteropancreatic neuroendocrine tumors.

Neuroendocrine tumors (NETs) are rare cancers that most often arise in the gastrointestinal tract and pancreas. The fundamental mechanisms driving gastroenteropancreatic (GEP)-NET growth remain incompletely elucidated; however, the heterogeneous clinical behavior of GEP-NETs suggests that both cellular lineage dynamics and tumor microenvironment influence tumor pathophysiology. Here, we investigated the single-cell transcriptomes of tumor and immune cells from patients with gastroenteropancreatic NETs. Malignant GEP-NET cells expressed genes and regulons associated with normal, gastrointestinal endocrine cell differentiation, and fate determination stages. Tumor and lymphoid compartments sparsely expressed immunosuppressive targets commonly investigated in clinical trials, such as the programmed cell death protein-1/programmed death ligand-1 axis. However, infiltrating myeloid cell types within both primary and metastatic GEP-NETs were enriched for genes encoding other immune checkpoints, including VSIR (VISTA), HAVCR2 (TIM3), LGALS9 (Gal-9), and SIGLEC10. Our findings highlight the transcriptomic heterogeneity that distinguishes the cellular landscapes of GEP-NET anatomic subtypes and reveal potential avenues for future precision medicine therapeutics.

Systemic Therapy for Tumor Control in Well-Differentiated Metastatic Gastroenteropancreatic Neuroendocrine Tumors: ASCO Guideline Q and A.

ASCO recently published new guidance on systemic therapy for tumor control in well-differentiated metastatic gastrointestinal and pancreatic neuroendocrine tumors in the Journal of Clinical Oncology. A companion Q and A article in the JCO-OP addresses some of the questions that clinicians may face as they implement these recommendations into clinical practice, including the role of somatostatin receptors and observation, definition of terms used within the guideline, considerations related to therapy options for G3 NETs, and future direction in research and treatment. ASCO also plans to address recommendations on the topic of symptom control of GEP-NETs in a forthcoming guideline

Systemic Therapy for Tumor Control in Metastatic Well-Differentiated Gastroenteropancreatic Neuroendocrine Tumors: ASCO Guideline.

To develop recommendations for systemic therapy for well-differentiated grade 1 (G1) to grade 3 (G3) metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs). ASCO convened an Expert Panel to conduct a systematic review of relevant studies and develop recommendations for clinical practice. Eight randomized controlled trials met the inclusion criteria for the systematic review. Somatostatin analogs (SSAs) are recommended as first-line systemic therapy for most patients with G1-grade 2 (G2) metastatic well-differentiated GI-NETs. Observation is an option for patients with low-volume or slow-growing disease without symptoms. After progression on SSAs, peptide receptor radionuclide therapy (PRRT) is recommended as systematic therapy for patients with somatostatin receptor (SSTR)-positive tumors. Everolimus is an alternative second-line therapy, particularly in nonfunctioning NETs and patients with SSTR-negative tumors. SSAs are standard first-line therapy for SSTR-positive pancreatic (pan)NETs. Rarely, observation may be appropriate for asymptomatic patients until progression. Second-line systemic options for panNETs include PRRT (for SSTR-positive tumors), cytotoxic chemotherapy, everolimus, or sunitinib. For SSTR-negative tumors, first-line therapy options are chemotherapy, everolimus, or sunitinib. There are insufficient data to recommend particular sequencing of therapies. Patients with G1-G2 high-volume disease, relatively high Ki-67 index, and/or symptoms related to tumor growth may benefit from early cytotoxic chemotherapy. For G3 GEP-NETs, systemic options for G1-G2 may be considered, although cytotoxic chemotherapy is likely the most effective option for patients with tumor-related symptoms, and SSAs are relatively ineffective. Qualifying statements are provided to assist with treatment choice. Multidisciplinary team management is recommended, along with shared decision making with patients, incorporating their values and preferences, potential benefits and harms, and other characteristics and circumstances, such as comorbidities, performance status, geographic location, and access to care.Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines.

Diagnostic accuracy of SSR-PET/CT compared to histopathology in the identification of liver metastases from well-differentiated neuroendocrine tumors

BackgroundHistopathology is the reference standard for diagnosing liver metastases of neuroendocrine tumors (NETs). Somatostatin receptor-positron emission tomography / computed tomography (SSR-PET/CT) has emerged as a promising non-invasive imaging modality for staging NETs. We aimed to assess the diagnostic accuracy of SSR-PET/CT in the identification of liver metastases in patients with proven NETs compared to histopathology.MethodsHistopathologic reports of 139 resected or biopsied liver lesions of patients with known NET were correlated with matching SSR-PET/CTs and the positive/negative predictive value (PPV/NPV), sensitivity, specificity, and diagnostic accuracy of SSR-PET/CT were evaluated. PET/CT reading was performed by one expert reader blinded to histopathology and clinical data.Results133 of 139 (95.7%) liver lesions showed malignant SSR-uptake in PET/CT while initial histopathology reported on ‘liver metastases of NET´ in 127 (91.4%) cases, giving a PPV of 91.0%. Re-biopsy of the initially histopathologically negative lesions (reference standard) nevertheless diagnosed ‘liver metastases of NET’ in 6 cases, improving the PPV of PET/CT to 95.5%. Reasons for initial false-negative histopathology were inadequate sampling in the sense of non-target biopsies. The 6 (4.3%) SSR-negative lesions were all G2 NETs with a Ki-67 between 2–15%.ConclusionSSR-PET/CT is a highly accurate imaging modality for the diagnosis of liver metastases in patients with proven NETs. However, we found that due to the well-known tumor heterogeneity of NETs, specifically in G2 NETs approximately 4–5% are SSR-negative and may require additional imaging with [18F]FDG PET/CT.

Bone fragility in well-differentiated gastroenteropancreatic-neuroendocrine tumors: Results from a retrospective two-centered study

Bone fragility in well-differentiated gastroenteropancreatic-neuroendocrine tumors: Results from a retrospective two-centered study

Predictors of recurrence following local excision for early-stage anal squamous cell carcinoma

IntroductionThere is increasing use of local excision (LE) for definitive treatment of early-stage anal squamous cell carcinoma (ASCC) to avoid the morbidity associated with chemoradiotherapy (CRT). However, the importance of different histological variables on risk of recurrence is poorly understood. MethodsA detailed analysis of patient characteristics, histology results, recurrence patterns and salvage treatment was conducted in consecutive T1/T2N0 ASCC patients treated by LE 2010–2021 across a UK regional cancer network multi-disciplinary team (MDT). Associations between potential predictors of disease recurrence were explored using chi-squared and Kruskal-Wallis tests for categorical and continuous variables respectively. ResultsOf 621 ASCC patients discussed in the network MDT, 164 had early-stage disease (T1/T2 N0). Of these, 36 (22%) were deemed suitable for LE (median age 61 years, female to male ratio 2:1). Twenty-two LE tumours were T1; 14 were T2. There were 12 well-differentiated tumours, 21 moderate and 3 poorly-differentiated. Seven out of 36 LE patients (19.4%) developed recurrence, all of whom went on to have salvage treatment with CRT (n = 4), re-excision (n = 2) or radiotherapy (n = 1). Predictors of disease recurrence following LE were: tumour differentiation (p = 0.024), tumour depth (p = 0.033) and R1 resection margin (p = 0.034). Tumour stage and site (margin/canal) were non-significant. ConclusionLE for T1/T2 N0 ASCC of the margin or canal is a viable treatment strategy to avoid the morbidity associated with CRT and salvage treatments are still available for patients that develop recurrence. Tumour differentiation, depth and margin status are all important factors to consider when discussing management of early-stage ASCC.

Investigation of pre-operative demographic, biochemical, sonographic and cytopathological findings in low-risk thyroid neoplasms.

The present article analyses pre-operative demographic, biochemical, sonographic and histopathological characteristics of low-risk thyroid neoplasms (LRTNs), with a focus on four subgroups, "well-differentiated carcinoma-not otherwise specified" (WDC-NOS), "non-invasive follicular thyroid neoplasm with papillary like nuclear features" (NIFTP), "well-differentiated tumours of uncertain malignant potential" (WDT-UMP) and "follicular tumour of uncertain malignant potential" (FT-UMP). The study retrospectively analyzed the histopathology of 2453 malignant thyroids and the final analyses included 99 cases diagnosed with LRTNs. The demographic and clinical features, pre-operative thyroid function, ultrasonography results, cytopathology results, histopathology results and prognostic classifications were assessed. The groups were similar demographic characteristics and the majority of clinical data, including comorbidities, thyroid function tests, thyroid cancer/neck radiotherapy history. NIFTPs represented 69.7% of all LRTNs. All (100%) WDT-UMPs had solitary nodules. Index nodule volume differed among the groups (p = .036), it was the lowest in WDC-NOS [0.68 (0.63-0.72 cc)] and highest in FT-UMP [12.6 (0.5-64 cc)]. Echogenicity findings were similar. Index nodule TIRADS demonstrated a significant difference (p = .021) but index nodule halo sign and BETHESDA scores were similar in all groups. The diameter, localisation and multicentric structure of LRTNs were again similar for all groups. Finally, prognostic scores suggested similar outcomes in all groups. The majority of LRTNs were NIFTPs in our population and all WDT-UMPs were solitary lesions. Index nodule volume was the most essential discriminating sonographic finding but further research must be performed before discriminatory potential can be described.

New developments in mesothelial pathology.

This review article examines some new and some problem areas in mesothelial pathology, four of which are discussed, as follows. (1) The concept of mesothelioma in situ: this lesion is defined as a single layer of bland mesothelial cells without evidence of invasion, but that have lost BAP1 and/or MTAP by immunohistochemistry. Benign reactions can exactly mimic mesothelioma in situ, but a hint to the correct diagnosis is a story of recurrent pleural effusions/ascites of unknown aetiology without radiological or direct visual evidence of tumour. (2) The nature of well-differentiated papillary mesothelial tumour (WDPMT): WDPMT has a long history of arguments regarding its behaviour, and this uncertainty can now be seen to arise, in part, from the observation that some forms of mesothelioma in situ microscopically look exactly like WDPMT. Hence, it is recommended to always run at least a BAP1 stain on any lesion that looks like WDPMT. Both flat and WDPMT-like mesothelioma in situ are strongly associated with eventual development of invasive mesothelioma, but this process is relatively slow. (3) New immunostains for separating mesothelioma from other tumours: here, it is proposed that in most cases, and particularly when the differential is epithelioid mesothelioma versus non-small cell lung cancer, one can make this separation with extremely high sensitivity and specificity using just two stains: HEG1 and claudin-4. (4) Markers for separating benign from malignant mesothelial proliferations: this topic is briefly reviewed, with an indication of which markers are generally accepted and the best utilisation and possible limitations of each marker.

Severe hypercalcemia due to metastatic pancreatic neuroendocrine tumor: a case report

BackgroundHypercalcemia of malignancy, as a paraneoplastic syndrome, is the most common metabolic disorder that accounts for 30% of malignancies and usually has a poor prognosis. Neuroendocrine tumors are uncommon and arise from neuroendocrine cells throughout the body. Actually, paraneoplastic hypercalcemia in neuroendocrine tumors is unusual and mostly associated with parathyroid hormone-related protein (PTHrP) secretion.Case presentationWe report a 51-year-old Iranian man who presented with nausea, vomiting, and significant weight loss for 1 month. Laboratory data revealed calcium of 26 mg/dl, accompanied by low level of PTH. Octreotide scan revealed a large donut-shaped octreotide avid lesion in the epigastric region at the right side of the mid-abdomen, with multiple varying size foci of abnormally increased radiotracer uptake in the epigastric region and both lobes of the liver. Endoscopic ultrasonography demonstrated a large heterogeneous mass lesion with irregular outline and good demarcation in the body of the pancreas with diffuse foci of calcification. Percutaneous biopsy of the liver mass demonstrated a well-differentiated neuroendocrine tumor (low grade) confirmed by immunohistochemistry with strongly positive chromogranin and synaptophysin stain. Hypercalcemia was treated with hydration, few sessions of hemodialysis, calcitonin, and denosumab injection. However, the patient developed symptomatic hypocalcemia. Oncology consultation led to prescription of long-acting octreotide 30 mg monthly and everolimus daily.ConclusionPancreatic neuroendocrine tumor could lead to malignant hypercalcemia; secretion of PTHrP is the most common cause, and signs and symptoms are usually milder than paraneoplastic syndrome due to hematologic and solid tumor. Generally, survival is better; however, its treatment is challenging, and primary debulking surgery is often required. A team approach to management is important at all points.

An institutional study: Does Body Mass Index influence surgical approach, surgical morbidities, and outcomes in endometrial cancer patients?

Endometrial Cancer (EC), the most common genital tract malignancy in women, is recognised to be associated with a high Body Mass Index (BMI). The aim of the study was to evaluate the impact of obesity on intra and post-operative morbidity for patients treated for EC. This was a retrospective observational study including patients with EC that were surgically treated at Hospital de la Santa Creu i Sant Pau during nine consecutive years. The patients were divided in groups according to BMI: <30 Kg/m2, ≥30-<40 Kg/m2 and ≥40 Kg/m2. Demographic and pathological characteristics, surgical outcomes, perioperative complications and long-term outcomes were recorded. The study included 290 patients; 164 patients with BMI <30 Kg/m2(56.5%), 107 patients with ≥30-<40 Kg/m2 36.9%) and 19 patients with ≥40 Kg/m2(6.65%). Patients with BMI ≥40Kg/m2 were younger, presented a higher percentage of endometrioid histology (84.2%, p<0.01), well-differentiated tumours (73.7%, p<0.01) and were more frequently in the initial stages at diagnosis (94.7%) compared to the other groups. A significant percentage of the patients were operated on laparoscopically (88.7%, 88.8%, 94.7% respectively). No significant differences were found in the evaluation of the surgical outcomes. The results relative to complications showed an overall tendency toward increase in the ≥40 Kg/m2 BMI group but no statistical differences were identified among the groups in terms of complications or long-term outcomes. There was a rising trend towards increased complications with increasing BMI in the study population, however, this was found not to be statistically significant. Therefore, the optimisation of co-morbidities and the adaptation of surgical treatment is important for the management of obese patients with endometrial cancer. The study allows the comparison between groups with different BMI in patients with endometrial cancer. Different surgical outcomes, intra operative, early, and late complications are clearly identified, and survival outcomes are also investigated in our study.

Revisiting the cytomorphological features of poorly differentiated thyroid carcinoma: a comparative analysis with indeterminate thyroid fine-needle aspiration samples.

Poorly differentiated thyroid carcinoma (PDTC) is an uncommon high-grade carcinoma of follicular cell origin that is usually overlooked on preoperative fine-needle aspiration (FNA) due to its rarity and cytomorphological overlap with follicular-patterned neoplasms. Definitive diagnosis of PDTC usually requires histologic examination of the resected thyroid tumor. Herein, we describe the cytological and architectural findings of histologically confirmed PDTC cases. A search for all thyroid FNAs with a corresponding surgical diagnosis of PDTC was performed. Surgical diagnoses were reviewed and confirmed using the Turin criteria. In addition, the control group consisted of indeterminate thyroid nodules (FLUS [follicular lesion of undetermined significance] and FN [follicular neoplasm]) that were either benign or well-differentiated thyroid tumors on resection. The PDTC and control groups were both subjected to cytological assessment using specific cytological and architectural parameters, which included cellularity, growth pattern, mitoses, necrosis, chromatin change, discohesion, and anisonucleosis. A total of 36 thyroid FNAs were included in the study. This consisted of 12 histologically confirmed PDTC FNAs and 24 indeterminate thyroid FNAs (FLUS and FN, 12 each). The most frequent findings among PDTC groups were hypercellularity (75%), trabecular/insular growth pattern (58%), branching capillaries (67%), and cellular discohesion (92%). Necrosis (25%), ≥3 mitoses (50%), and anisonucleaosis (42%) were less frequently observed. A peculiar finding was the presence of adenoid cystic carcinoma-like globules in 50% of PDTC cases. Certain findings such as colloid, necrosis, mitoses, and cellular discohesion were helpful in differentiating the two groups. Thyroid fine-needle aspiration remains an essential diagnostic/triage tool for most thyroid nodules/tumors. PDTC can be diagnosed or at least suspected preoperatively based on the demonstration of certain architectural and cytological alterations. Although mitoses and necroses are not always readily identified, an elevated Ki-67 labeling expression could provide additional clues to the diagnosis in some cases.