Extrathyroidal Calcitonin Secreting Tumors: Pancreatic Neuroendocrine Tumors in Patients With Multinodular Goiter: Two Case Reports

Whole-exome sequencing of calcitonin-producing pancreatic neuroendocrine neoplasms indicates a unique molecular signature

Introduction

Calcitonin-producing pancreatic neuroendocrine neoplasms (CT-pNENs) are an extremely rare clinical entity, with approximately 60 cases reported worldwide. While CT-pNENs can mimic the clinical and diagnostic features of medullary thyroid carcinoma, their molecular profile is poorly understood.

Methods

Whole-exome sequencing (WES) was performed on tumor and corresponding serum samples of five patients with increased calcitonin serum levels and histologically validated calcitonin-positive CT-pNENs. cBioPortal analysis and DAVID gene enrichment analysis were performed to identify dysregulated candidate genes compared to control databases. Immunohistochemistry was used to detect the protein expression of MUC4 and MUC16 in CT-pNEN specimens.

Results

Mutated genes known in the literature in pNENs like MEN1 (35% of cases), ATRX (18-20% of cases) and PIK3CA (1.4% of cases) were identified in cases of CT-pNENs. New somatic SNVs in ATP4A, HES4, and CAV3 have not been described in CT- pNENs, yet. Pathogenic germline mutations in FGFR4 and DPYD were found in three of five cases. Mutations of CALCA (calcitonin) and the corresponding receptor CALCAR were found in all five tumor samples, but none of them resulted in protein sequelae or clinical relevance. All five tumor cases showed single nucleotide variations (SNVs) in MUC4, and four cases showed SNVs in MUC16, both of which were membrane-bound mucins. Immunohistochemistry showed protein expression of MUC4 in two cases and MUC16 in one case, and the liver metastasis of a third case was double positive for MUC4 and MUC16. The homologous recombination deficiency (HRD) score of all tumors was low.

Discussion

CT-pNENs have a unique molecular signature compared to other pNEN subtypes, specifically involving the FGFR4, DPYD, MUC4, MUC16 and the KRT family genes. However, a major limitation of our study was the relative small number of only five cases. Therefore, our WES data should be interpreted with caution and the mutation landscape in CT-pNENs needs to be verified by a larger number of patients. Further research is needed to explain differences in pathogenesis compared with other pNENs. In particular, multi-omics data such as RNASeq, methylation and whole genome sequencing could be informative.

A calcitonin-producing pancreatic neuroendocrine neoplasm treated with distal pancreatectomy a lengthy time after a left trisectionectomy for liver metastases: a case report

BACKGROUND

Calcitonin-producing pancreatic neuroendocrine neoplasms (PanNENs) are extremely rare. There have been no reports of a patient in whom liver metastases were the presenting finding, and a calcitonin-producing PanNEN was subsequently detected after a lengthy period.

CASE PRESENTATION

A 53-year-old man had diarrhea for several years. Computed tomography (CT) revealed multiple liver tumors. We performed a left trisectionectomy with a bile duct resection. The histologic examination showed neuroendocrine tumors G1. Immunohistochemistry was positive for calcitonin and the serum calcitonin level was elevated. Neuroendocrine neoplasms of hepatic origin are extremely rare, so a systemic exploration was performed, but no tumor was detected. CT showed a 4-mm calcification in the pancreatic body, but no contrast-enhanced mass was noted. Although the liver tumors were resected, the diarrhea and high serum calcitonin level persisted. Serial examinations were performed for 6 years, but no tumor was identified; however, 6.5 years after the hepatectomy the serum calcitonin level increased. CT showed a 10-mm contrast-enhanced mass in the calcified area of the pancreatic body. A distal pancreatectomy was performed. The histologic examination showed a neuroendocrine tumor G1, which mimicked the liver tumors. Immunohistochemistry was positive for calcitonin. After the distal pancreatectomy, the serum calcitonin level decreased and diarrhea resolved. The calcitonin-producing neuroendocrine neoplasm was considered the pancreatic primary and the hepatic tumors were metastases.

CONCLUSIONS

Calcitonin-producing PanNENs may be initially recognized as liver tumors and may become evident after a lengthy period, thus long-term observation is recommended. Aggressive surgeries may contribute to long-term survival.

Presence or severity of Hashimoto's thyroiditis does not influence basal calcitonin levels: observations from CROHT biobank

PURPOSE

The influence of Hashimoto's thyroiditis (HT) on calcitonin (Ct) production is unresolved question. The aim of this study was to explore if basal Ct levels are influenced by the presence/severity of HT or correlated with clinical phenotypes of HT patients.

METHODS

We included 467 HT patients and 184 control participants, from Croatian Biobank of HT patients (CROHT), in this retrospective study. Calcitonin levels between HT patients and controls were compared using Mann-Whitney test. Ct levels between two subgroups of HT patients, divided by intake of levothyroxine (LT4) therapy, were additionally tested to take into account the illness severity. Spearman rank correlation test was used to analyze correlations between Ct levels and 14 relevant phenotypes.

RESULTS

We have not detected significant differences in median Ct levels between HT patients and controls (2.2 vs 2.35 pg/mL, respectively, P = 0.717) nor in-between two subgroups of HT patients (P = 0.347). We have not detected statistically significant correlations between Ct levels and clinical phenotypes, although we identified three weak nominal correlations: negative correlation of Ct with TgAb in all HT patients (r = - 0.1, P = 0.04); negative correlation of Ct with age in subgroup of HT patients without LT4 therapy (r = - 0.13, P = 0.04); positive correlation of Ct with BSA in subgroup of HT patients on LT4 therapy (r = 0.16, P = 0.042).

CONCLUSION

Our results suggest that HT patients of all disease stages preserve Ct production as healthy individuals and there is no need for Ct measurements in the absence of a nodule. Additional confirmation and clarification of observed nominal correlations are needed due to potential clinical relevance of TgAb and age-dependent Ct decrease in HT women.

Neuroendocrine tumor with diarrhea: not always the usual suspects - a case report of metastatic calcitoninoma with literature review

We describe a case of a 59-year-old man without relevant past medical history, presenting with chronic diarrhea and weight loss. Extensive laboratory analysis, stool cultures and gastro- and ileocolonoscopy could not identify a diagnosis. Abdominal imaging revealed a mass in the uncinate process of the pancreas with mesenteric adenopathies and liver metastases. Fine needle aspiration was compatible with a pancreatic neuroendocrine tumor with low proliferative capacity (Ki-67 <1%). Immunohistochemical staining was positive for calcitonin and serum calcitonin levels were clearly elevated. Surprisingly, ¹⁸FDG PET-CT scan was positive, but no tracer uptake was seen on ⁶⁸Gallium-DOTATOC PET-CT scan. Treatment with somatostatin analogues was not successful, but long-term tumor control could be obtained with Everolimus. However, no significant effect was seen on stool frequency despite additional treatment with multiple symptomatic therapies, liver-directed therapy with radio- and chemoembolization and additional external radiotherapy to the primary pancreatic tumor. Ondansetron, eventually, seems to be the only therapy, until now, causing a decrease in stool frequency.Functioning pancreatic calcitoninomas are considered to be a rare disease entity with few literature on optimal (nuclear) imaging and treatment. We discuss molecular insights regarding these aspects that can be of great interest to nuclear medicine physicians, pathologists, endocrinologists and gastroenterologists.

Case Report: Unmasking Hypercalcemia in Patients With Neuroendocrine Neoplasms. Experience From Six Italian Referral Centers

BACKGROUND

Hypercalcemia is a common paraneoplastic syndrome which can occur in up to 10% of patients with advanced neoplasms. Paraneoplastic parathyroid hormone-related protein (PTHrP) represents the most frequent cause of this syndrome. In neuroendocrine neoplasms (NENs) paraneoplastic hypercalcemia is rare.

CASE SERIES

The present series includes all patients with NENs and paraneoplastic hypercalcemia from four Italian centres: (I) A 40-year-old man was hospitalized for repeated episodes of falls, hyposthenia and drowsiness. Severe hypercalcemia was found. Metastatic pancreatic G2 NEN and PTHrP-related hypercalcemia were diagnosed. The patient started therapy with somatostatin analogs (SSA) and Denosumab. After disease progression peptide receptor radionuclide therapy (PRRT) was started with an objective response associated with PTHrP reduction and normocalcemia. (II) A 45-year-old man was referred for pancreatic G2 NEN. SSA and subsequently everolimus were administered for metastases occurrence. Hypercalcemia occurred and PRRT and Denosumab were started for disease progression with the onset of bone metastases. Despite disease stability after four cycles of PRRT the patient's performance status worsened until death. (III) A 49-year-old woman was hospitalized for psychic slowdown, confusional state, sensory dullness. A severe hypercalcemia, associated with a pancreatic G1 NEN was diagnosed and treated with haemodialysis, bisphosphonates injections and continuous infusion of calcitonin. 1,25-dihydroxyvitamin D was high, PTHrP was undetectable. After surgery serum calcium levels and 1,25-dihydroxyvitamin D were normalized. (IV) A 69-year-old man was hospitalized after the onset of shortness of breath and dyspnea, asthenia and weight loss. Computed Tomography (CT) and ⁶⁸Ga DOTATOC Positron Emission Tomography (PET)-CT revealed a left pulmonary nodule. Hypercalcemia and markedly elevated PTHrP levels were detected. The histological examination revealed an atypical carcinoid. After surgery, calcium levels were normalized, PTHrP was significantly reduced with an improvement of general conditions.

CONCLUSION

In our series, paraneoplastic PTHrP-related hypercalcemia occurred in pancreatic NEN and in one bronchial carcinoid representing the third case in the literature. Our case associated with 1,25-dihydroxyvitamin D secretion represents the fourth case in the literature. PTHrP secretion should be considered in NENs' patients with hypercalcemia. Acute treatment should be focused on lowering calcium levels, and long-term control can be achieved by tumor cytoreduction inhibiting PTHrP release.

Untargeted longitudinal analysis of a wellness cohort identifies markers of metastatic cancer years prior to diagnosis

We analyzed 1196 proteins in longitudinal plasma samples from participants in a commercial wellness program, including samples collected pre-diagnosis from ten cancer patients and 69 controls. For three individuals ultimately diagnosed with metastatic breast, lung, or pancreatic cancer, CEACAM5 was a persistent longitudinal outlier as early as 26.5 months pre-diagnosis. CALCA, a biomarker for medullary thyroid cancer, was hypersecreted in metastatic pancreatic cancer at least 16.5 months pre-diagnosis. ERBB2 levels spiked in metastatic breast cancer between 10.0 and 4.0 months pre-diagnosis. Our results support the value of deep phenotyping seemingly healthy individuals in prospectively inferring disease transitions.

Malignant Insulinoma with Multiple Liver Metastases and Hypercalcitoninemia in a Patient with Type 2 Diabetes Mellitus Presenting as Recurrent Episodes of Diaphoresis due to Severe Hypoglycemia

Insulinoma is an insulin-producing pancreatic neuroendocrine tumor that can be malignant in about 10% of cases. Locoregional invasion, lymph node metastases, or remote metastases are the main criteria of malignant insulinoma. Its incidence in patients with pre-existing diabetes mellitus (DM) is exceptionally rare. In this report, we describe a 66-year-old man with long-standing type 2 DM who presented with recurrent episodes of diaphoresis due to severe hypoglycemia despite the withdrawal of insulin therapy, hypercalcitoninemia, and biochemical and radiological findings suggestive of metastatic malignant insulinoma. Unfortunately, after few days of diazoxide treatment, edema, hypotension, oliguria, and water retention were observed, patient's clinical status deteriorated rapidly, and he died in our department from acute renal failure.

Laryngeal Neuroendocrine Tumor With Elevated Serum Calcitonin: A Diagnostic and Therapeutic Challenge. Case Report and Review of Literature

Introduction: Laryngeal neuroendocrine neoplasms (NENs) are a rare group of NENs of the neck, which commonly show immunostaining for calcitonin. Laryngeal NENs with calcitonin hypersecretion and lymph node metastases represent a diagnostic and therapeutic challenge, which should be included in the differential diagnosis of medullary thyroid carcinoma (MTC). We report a complex case of laryngeal NEN with calcitonin hypersecretion and a review of the literature. Case Presentation: A 59-year-old man presented with dysphagia, dyspnea, and lateral cervical mass; he was a smoker. At first imaging, a laryngeal lesion with lateral cervical lymphadenopathies was found, and it resulted as a moderately differentiated neuroendocrine tumor (G2), Ki67 = 5%, positive for calcitonin. Increased levels of serum calcitonin (50 pg/ml) were found. The patient started somatostatin analogs for lesions positivity to somatostatin receptor-based imaging. After 5 months, the disease progressed at 18F-fluorodeoxyglucose (¹⁸F-FDG) PET-CT, and also new painful cutaneous lesions occurred. Considering high serum levels of calcitonin, differential diagnosis with MTC was required. Patient performed a thyroid color Doppler ultrasound, nodule fine needle aspiration, calcitonin dosage in fine needle washout fluid, and a calcium gluconate stimulation test. After multidisciplinary evaluation, we decided to perform a total thyroidectomy associated with lateral cervical lymphadenectomy and resection of skin metastases. No MTC was found. Two of the five resected lymph nodes, left upper parathyroid, and skin lesions were metastases of NEN G2, positive for calcitonin. After 2 months, new painful skin lesions occurred, and a target therapy with everolimus 10 mg/day was started. After 6 months of therapy, partial metabolic response with a reduction of 53.7% of radiotracer uptake at primary tumor was detected together with an improvement of patient's quality of life. Conclusions: The present case is the seventh described in the literature of laryngeal NEN associated with elevated serum calcitonin levels and the first case with parathyroid metastasis, suggesting the importance of a correct differential diagnosis between MTC and calcitonin-secreting laryngeal NEN, using an integrated approach of biochemistry and advanced imaging. This is also the first time that somatostatin analogs and then everolimus were used in this setting, resulting in clinical and partial metabolic response.

Calcitonin-Producing Neuroendocrine Neoplasms of the Pancreas: Clinicopathological Study of 25 Cases and Review of the Literature

Increased levels of circulating calcitonin are a clue in the diagnosis of medullary thyroid carcinoma. However, hypercalcitoninemia can also be related to other pathological conditions, including pancreatic neuroendocrine neoplasms (PanNENs). Ectopic hormonal production is not unusual in both functioning and non-functioning PanNENs; however, little is known about the frequency of calcitonin expression in these neoplasms. The aims of this study were to assess the frequency of calcitonin immunoreactivity in PanNENs, independently from serum calcitonin levels, and to evaluate the clinicopathological and prognostic features of calcitonin-immunoreactive (Cal-IR) PanNENs, including a comparison with cases already reported in the literature. We screened 229 PanNENs for the immunohistochemical expression of calcitonin, including both functioning and non-functioning neoplasms, as well as both well-differentiated and poorly differentiated PanNENs. Both the clinicopathological data and the follow-up information were available and were compared with the immunohistochemical results. In addition, we reviewed the features of the calcitonin-producing PanNENs previously reported in the literature. Calcitonin was expressed in 25 of our 229 PanNENs (10.9%). Examples of well- and poorly differentiated, as well as both functioning and non-functioning PanNENs, were found to be calcitonin immunoreactive. Cal-IR PanNENs did not show any significant difference with the whole series of neoplasms included in the study, when the clinicopathological parameters were considered, except for a younger age at diagnosis and for a larger size of the tumor in non-functioning Cal-IR PanNENs. Taken together, our results show that calcitonin immunoreactivity is not an exceptional event in PanNENs. Furthermore, calcitonin expression does not identify a separate clinical entity, in contrast to other PanNENs with ectopic hormone production, such as adrenocorticotropic hormone (ACTH)-producing PanNENs, which show a distinctively more aggressive behavior.

Metastatic medullary thyroid carcinoma or calcitonin-secreting carcinoid tumor of lung? A diagnostic dilemma in a patient with lung mass and thyroid nodule

Calcitonin-secreting neuroendocrine tumors are rare and have been reported in literature as case reports or case series in various organs including lung, pancreas, larynx, bladder, and ovary. These tumors have similar cytologic features and immunohistochemical profile to medullary thyroid carcinoma and thus it is difficult to distinguish them, especially when calcitonin-secreting neuroendocrine tumors are intermediate or higher grade and there is a mass lesion in the thyroid gland. Here, we report a rare case of calcitonin secreting atypical carcinoid tumor of the lung in a patient with thyroid nodule. However, after extensive ancillary studies on the thyroid gland, no tumor was detected and subsequent resection specimen revealed a pulmonary atypical carcinoid tumor with metastasis to level 11 lymph node. Being aware of this entity has significant clinical, diagnostic, and therapeutic implications and can prevent unnecessary thyroidectomies with subsequent possible morbidities.