Introduction:
Neuroendocrine tumors (NET) are a highly aggressive heterogeneous group
of neoplasms that arise from a combination of neural and hormonal cell
types. They most commonly arise from the lungs, small intestine,
appendix, and pancreas and less frequently from the thyroid,
parathyroid, pituitary and adrenal glands. There are several different
classifications based on differentiation of tumor cells in comparison to
neighboring non-neoplastic cells, however, in general tumors that are
well differentiated are low grade and those with poor differentiation
are high grade. Large cell neuroendocrine carcinoma was first proposed
by Travis et al. in 1991 and subsequently classified as high grade
neuroendocrine carcinoma (HGNEC) by the World Health Organization (WHO)
International Histological Classification of Tumours. HGNEC is a rare
tumor with unclear clinicopathologic features. Patients typically
present with widespread metastatic disease and the prognosis is poor
given the high mortality rate. Herein, we describe a rare case of
pancreatic HGNEC, large cell type, associated with a Cushing’s syndrome
presentation.