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Myoepithelioma of the parotid gland with extensive adipocytic metaplasia: Report of a case with intriguing aspects on fine needle aspiration and p63 immunohistochemical expression
Author(s) -
Schneider Vanessa,
Nobile Antoine,
Duvoisin Bertrand,
Saglietti Chiara,
Bongiovanni Massimo
Publication year - 2016
Publication title -
diagnostic cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.417
H-Index - 65
eISSN - 1097-0339
pISSN - 8755-1039
DOI - 10.1002/dc.23550
Subject(s) - myoepithelial cell , myoepithelioma , pathology , salivary gland , medicine , parotid gland , immunohistochemistry , histology , population , anatomy , environmental health
Myoepithelioma is a rare and usually benign salivary gland tumor derived from myoepithelial cells. Variability in cellular morphology and stromal composition leads to diagnostic pitfalls on fine‐needle aspiration cytology; therefore, histology and immunohistochemistry are often required for definitive diagnosis. We describe a case of parotid gland myoepithelioma in a 76‐year‐old woman, which was discovered incidentally on cerebral magnetic resonance imaging. Fine‐needle aspiration sampled cohesive aggregates of spindle‐shaped cells embedded in a fibrillary matrix as well as abundant mature adipocytes, initially considered as part of normal salivary gland parenchyma. Histology of the resected specimen showed bundles of spindle‐shaped cells embedded in loose connective tissue, admixed with numerous intralesional adipocytes. Immunohistochemical studies revealed a diffuse expression of p63 by this adipocytic population, an observation clearly indicating that myoepithelial cells can trans‐differentiate and acquire the morphology of mature adipocytes. Knowledge of this phenomenon can be helpful in the work‐up of salivary gland lesions. Diagn. Cytopathol. 2016;44:1090–1093. © 2016 Wiley Periodicals, Inc.