Histologic variant of the epithelial-myoepithelial carcinoma of the salivary gland: a case report.
BACKGROUND
Epithelial-myoepithelial carcinoma (EMC) of the salivary gland is a low-grade carcinoma. It has been widely accepted as a clinicopathologic entity only in the past decade. Histologically, the classical bimodal differentiation of inner eosinophilic ductal cells and outer layer of clear myoepithelial cells has been well documented by many authors. However, the proportion of each component may vary in different tumors or within the same tumor, and different histologic patterns have been described. The clinicopathologic findings of an epithelial-myoepithelial carcinoma of the parotid gland in a 73-year-old man are presented.


METHODS
Light microscopy including immunohistochemistry and ultrastructural studies were done.


RESULTS
The various histologic patterns and bimodal differentiation of the tumor were noted.


CONCLUSIONS
The present case demonstrates the myriad of histologic patterns that can occur in epithelial-myoepithelial carcinoma. Differentiation from malignant mixed tumor is essential and possible. The importance of the awareness of its histologic variants is emphasized.
Department of Pathology, Pamela Youde Nethersole Eastern Hospital, Chaiwan, Hong Kong.
F M
FM
Cheung
F
F
Hioe
J H
JH
Kong
D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D000368:Aged; D001706:Biopsy; D002277:Carcinoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009361:Neoplasm Invasiveness; D016609:Neoplasms, Second Primary / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D010307:Parotid Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed