title: Spindle cell oncocytoma of the adenohypophysis.
abstract: Spindle cell oncocytoma of the adenohypophysis (SCO) is defined as spindle to epithelioid cells with oncocytic appearance presenting in the adenohypophysis. In contrast to pituitary adenomas, the SCO does not show immunoreactivity for neuroendocrine markers and pituitary hormones but co-expressed vimentin, S-100 protein, epithelial membrane antigen (EMA), and antimitochondrial antibody MU213-UC clone 131-1. We describe an SCO in an adult, a 42-year-old woman whose magnetic resonance (MR) images documented an intrasellar lesion located in the hypophysis. Histopathological examination showed a tumor composed predominantly of spindle cells. Immunohistochemical studies showed positivity for vimentin, S10, EMA, and antimitochondrial antibody MU213-UC clone 131. Cytokeratin (CK) (AE1/AE3), glial fibrillary acidic protein (GFAP), chromogranin, synaptophysin, PGP9.5, CD57, desmin, D2-40, smooth muscle actin (SMA), Bcl-2, progesterone receptor, and CD34 were negative. Neuropeptides were negative. With electron microscopy, the neoplastic cells appear filled with mitochondria, well-formed desmosomes, but lacked secretory granules. SPO is a rare non-endocrine neoplasm of the adenohypophysis with benign biological behavior corresponding to WHO grade I.
authors.affiliation: Grupo de Patología del Instituto Nacional de Cancerología INC, Bogotá, Colombia. aromero@cancer.gov.co
authors.forename: Alfredo Ernesto
authors.initials: AE
authors.lastname: Romero-Rojas
authors.forename: Mario Alexander
authors.initials: MA
authors.lastname: Melo-Uribe
authors.forename: Paula Alejandra
authors.initials: PA
authors.lastname: Barajas-Solano
authors.forename: Sandra Isabel
authors.initials: SI
authors.lastname: Chinchilla-Olaya
authors.forename: Ligia Inés Restrepo
authors.initials: LI
authors.lastname: Escobar
authors.forename: Diana Marcela
authors.initials: DM
authors.lastname: Hernandez-Walteros
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology*; D000328:Adult; D005260:Female; D006801:Humans; D010903:Pituitary Gland, Anterior / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000473:pathology*