title: Oncocytic adrenocortical tumors:  diagnostic algorithm and mitochondrial DNA profile in 27 cases.
abstract: The pathologic diagnosis of adrenocortical carcinoma (ACC) relies on microscopic features that are sometimes equivocal in special variants, including oncocytic adrenocortical tumors (OACTs). We report a series of 27 unpublished OACTs (15 pure and 12 mixed or focal) and assess for the first time in OACTs the diagnostic utility of an algorithm recently proposed by our group ("reticulin" algorithm) for conventional ACCs on the basis of a combination of reticulin staining and assessment of only 3 Weiss parameters. Overall, 12 cases were malignant according to the Lin-Weiss-Bisceglia (L-W-B) system for pure tumors and the original Weiss system for mixed or focal tumors; extensive or focal disruption of the reticulin network was found in 16 of 27 OACTs. This was associated with either a high mitotic index, presence of necrosis, and/or vascular invasion in 14 of these, which were thus considered malignant according to our algorithm. From a clinical standpoint, OACTs, at least in the pure form, are "low grade" lesions with a low mean Weiss score, mitotic and Ki-67 indices, and uncommon capsular or vascular invasion. They, including unequivocal morphologically malignant cases, generally pursue an indolent clinical course. In addition, the 4977 bp mitochondrial DNA "common deletion" was detected using real-time polymerase chain reaction in 54% of cases from this study and an additional validation series of 23 OACTs, with a heterogenous (heteroplasmic) intratissue and intracellular distribution (as detected by a modified FISH procedure) and a marked association with the presence of intact reticulin framework.
authors: Division of Pathology, Department of Clinical and Biological Sciences, University of Turin at San Luigi Hospital, Orbassano, Torino, Italy.
authors: Eleonora
authors: E
authors: Duregon
authors: Marco
authors: M
authors: Volante
authors: Susanna
authors: S
authors: Cappia
authors: Alessandra
authors: A
authors: Cuccurullo
authors: Michele
authors: M
authors: Bisceglia
authors: Daniel D
authors: DD
authors: Wong
authors: Dominic V
authors: DV
authors: Spagnolo
authors: Sylwia
authors: S
authors: Szpak-Ulczok
authors: Enrico
authors: E
authors: Bollito
authors: Fulvia
authors: F
authors: Daffara
authors: Alfredo
authors: A
authors: Berruti
authors: Massimo
authors: M
authors: Terzolo
authors: Mauro
authors: M
authors: Papotti
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D018268:Adrenocortical Carcinoma / Q000175:diagnosis* / Q000235:genetics*; D000328:Adult; D000368:Aged; D000465:Algorithms; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D012155:Reticulin / Q000096:biosynthesis
chemical_list: D004272:DNA, Mitochondrial; D012155:Reticulin