Endocrine Abstracts

Introduction: Besides medullary thyroid carcinoma (MTC), increased calcitonin serum concentrations may be due, rarely, to neuroendocrine tumour (NET) ectopic secretion, especially those of the foregut (pancreatic/lung). Patients with NETs and right-sided heart failure due to cardiac carcinoid have a worse prognosis than those presenting without.

Case presentation: We present the case of a 72-year-old female with a history of an initially considered well-differentiated non-functional pancreatic NET who underwent three surgical interventions (2008 – body and tail pancreatic excision and splenectomy, 2012 - portal vein invasion and thrombosis, 2015- removal of liver metastases). Immunohistochemistry (IHC) showed positive reactions for CK19, CK7, vimentin, chromogranin A, synaptophysin and NSE in the primary tumour, with positive chromogranin A, synaptophysin and Ki-67 of 10% in the portal vein tumour. Since the first manifestations of the carcinoid syndrome (2009) she has been treated with Octreotide LAR (maximum dose 60 mg/month). She also received chemotherapy: FOLFOX in 2015, and after a voluntary drug holiday, Irinotecan was administered between 2017-2018 and 2020-2021. After the first course of Irinotecan, radiological regression of the hepatic hilum lymph nodes and VI segment nodules (abdominal CT scan, 2016) was noted, whereas without any chemotherapy treatment (2018-2020), abdominal MRI showed progression of the hilum and hepatic nodules. In 2021, under the second Irinotecan course, tumoral growth was noticed, so chemotherapy was stopped and targeted therapy with Sunitinib was introduced. The patient developed cardiac carcinoid (elevated NT-proBNP, 239.4 pg/ml in March 2021), associating a mild tricuspid regurgitation.

All neuroendocrine tumour serum markers were within the normal range under treatment, except for calcitonin serum levels, reaching levels as high as 2452 pg/ml in 2021, currently with decreasing values. The patient also associates secondary diabetes under insulin therapy, permanent levothyroxine substitutive treatment for postoperative hypothyroidism (2009, microfollicular adenoma) and secondary hyperparathyroidism due to vitamin D deficiency.

Conclusion: We presented a complex case of a patient with pancreatic NET who underwent multimodal treatment, associated with paraneoplastic calcitonin hypersecretion and cardiac carcinoid. Calcitonin-secreting NETs are rare, studies reporting that gastroenteropancreatic-NETs with high serum calcitonin have a worse prognosis that those with normal calcitonin. High calcitonin in NETs is associated with high-grade tumours, our case being of intermediate grade, further studies being needed to confirm the link between calcitonin and the clinical outcome of patients with NETs. Nozières C et al, Neuroendocrine tumors producing calcitonin: characteristics, prognosis and potential interest of calcitonin monitoring during follow-up. EJE. 2016 Mar;174(3):335-41.