Clinico-pathological features of a series of 11 oncocytic endocrine tumours of the pancreas.
Oncocytic changes may occur very infrequently in neuroendocrine tumours. To estimate the prevalence, pathological features and clinical behaviour of oncocytic endocrine tumours of the pancreas, we reviewed a series of 227 lesions from two institutions. Eleven cases with predominant oncocytic features were selected, representing 4.85% of the whole series. The morphological features and immunophenotype of such tumours did not differ from conventional endocrine pancreatic tumours, except for the presence of abundant eosinophilic and granular cytoplasm. Anti-mitochondrial antigen was positive in all cases tested, and by electron microscopy, numerous mitochondria were observed in the cytoplasm of tumour cells. The majority of cases were nonfunctioning, and in most cases, pathologic signs of malignancy, leading to a diagnosis of endocrine carcinoma, were observed. In addition, the three nonmalignant cases matched the criteria of well-differentiated tumours of uncertain malignant potential. Nearly 50% of the cases were clinically aggressive, and lymph node and liver metastases were present at the time of diagnosis in a minority of cases. Therefore, oncocytic endocrine pancreatic tumours represent a peculiar morphological and clinical variant characterised by frequent hormonal inactivity and malignant behaviour, which should be considered in the differential diagnosis, especially when dealing with a metastatic lesion.
Volante
Marco
M
Department of Biomedical Sciences and Human Oncology, University of Turin, Via Santena 7, 10126, Turin, and Department of Pathology, Ospedale di Circolo, Varese, Italy.
La Rosa
Stefano
S
Castellano
Isabella
I
Finzi
Giovanna
G
Capella
Carlo
C
Bussolati
Gianni
G
D018249:Adenoma, Oxyphilic / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000648:ultrastructure; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D008928:Mitochondria / Q000648:ultrastructure; D009361:Neoplasm Invasiveness / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*