Malignant pancreatic oncocytoma. An unusual cause of organic hypoglycemia

Abstract

A case of malignant islet-cell tumor with oncocytic features occurring in a 54-year-old woman with symptoms of organic hypoglycemia is reported. The tumor was composed of ribbons of cells arranged in an endocrine pattern. The cytoplasm of these cells was eosinophilic and finely granular. Ultrastructurally, the cells contained numerous mitochondria and dense-core neurosecretory granules. Tumor cells were focally immunoreactive for neuron-specific enolase, insulin, glucagon and VIP. Capillaries invasion and metastases to lymph nodes argued in favor of malignancy but there was no subsequent malignant involvement during a 3-year follow-up after surgery. Such insulinomas with oncocytic features have not been previously described. Endocrine features in oncocytomas of the pancreas and of other locations are discussed.

Clinico-pathological features of a series of 11 oncocytic endocrine tumours of the pancreas

“…In the pancreas, endocrine tumours composed of oncocytic cells have been described also, either sporadic [8,15,28,33,36,37] or associated to inherited multiple endocrine tumour syndromes such as Von Hippel-Lindau disease [10].…”

“…In the pancreas, although no oncocytic cells have been described in the normal endocrine component, single cases of oncocytic neuroendocrine tumours have been reported [8,15,28,33,36,37]. In a recent report, a biphasic tumour with typical endocrine cells and oncocytes was associated with Von Hippel-Lindau disease [10].…”

“…Among these, accounting to a total of eight cases so far reported in the literature to our knowledge, all cases but one were malignant, and the majority was nonfunctioning. The functioning tumours were two insulinomas [33,37], whereas one other reported case [36] was associated with the glucagonoma syndrome with insulin-dependent diabetes mellitus and chronic diarrhea and focal immunohistochemical positivity for insulin, glucagon and somatostatin. It is interesting that in the case reported by Chetty and co-workers [10], the oncocytic component showed widespread vascular invasion and lymph node involvement.…”

Metastatic papillary oncocytic carcinoma of the pancreas to the liver diagnosed by fine-needle aspiration

“…5 The pancreas is a rare site of oncocytic neoplasms, with only 14 cases reported in the literature. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] Of these, only two have been diagnosed by fine-needle aspiration (FNA) 16,19 (Table I). We present an additional case of metastatic papillary pancreatic oncocytic tumor diagnosed by FNA biopsy (FNAB).…”

Pancreatic Oncocytic Endocrine Tumors

“…8,16 Sadoul et al described a pancreatic malignant endocrine oncocytoma. 22 In this report we describe the fine needle aspiration (FNA) cytologic features of two oncocytic tumors of the pancreas, as observed in the primary lesion and in metastatic liver deposits.…”