Tumor Related- and Non-tumor-Related Diarrhea in a Medullary Thyroid Cancer Patient

Medullary thyroid cancer (MTC) is a rare malignancy originating from calcitonin-producing parafollicular C cells of the thyroid. In advanced disease, hormonal secretion by the tumor cells of calcitonin or other active peptides can cause systemic symptoms. Occasionally, MTCs release corticotropin (ACTH) causing ectopic Cushing’s syndrome. Although the pathogenesis is unclear, diarrhea and facial flushing are more common in MTC, and the management of potentially disabling symptoms is essential to improve the quality of life of these patients. Adequate symptomatic control is needed because chronic diarrhea impairs the quality of life and, when severe, may cause volume depletion and acid-base and electrolyte abnormalities. The initial treatment approach is based on the use of antimotility agents, while somatostatin analogs are a cornerstone in the management of carcinoid syndrome-related diarrhea. Multikinase inhibitors used for the treatment of progressive, advanced disease may also cause diarrhea as a drug-associated adverse event. This case report describes the management of a man with MTC who suffered from diarrhea as the main symptom of the disease. Diarrhea was the earliest, misdiagnosed symptom at presentation of MTC as well as an adverse event of systemic treatment (cabozantinib)

Functional and Radiological Imaging of Neuroendocrine Neoplasms

Imaging of neuroendocrine neoplasms (NENs) is extremely rich and varied. Conventional techniques of morphological imaging (ultrasound, CT, MRI) are complementary to other imaging techniques such as endoscopic explorations and functional imaging using radiopharmaceutical imaging techniques. NENs have very distinct functional characteristics, which make them ideal targets for functional molecular imaging. Functional imaging plays a crucial role in the assessment of initial tumor distribution (staging), disease assessment after therapy (restaging), disease follow-up, and planning for somatostatin receptor (SSTR) 2-based radiopeptide treatment. Other tracers, such as 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy or 18F-DOPA (dihydroxyphenylalanine) and the SSTR2-antagonist (NODAGA-JR11) PET/CT have been developed for specific indications or to gain sensitivity and specificity. The more aggressive, less differentiated neuroendocrine carcinomas tend to have less SSTR2 receptor expression, and the tumor cell metabolism shifts toward anaerobic glycolysis. In these patients, receptor-based imaging should be complemented or replaced by metabolic 18F-FDG (18F-fluorodeoxyglucose) PET/CT. The continuum from well-differentiated neuroendocrine tumor to a more aggressive neuroendocrine carcinoma makes functional imaging sometimes challenging