Cytological diagnosis of carcinoma ex-pleomorphic adenoma

Abstract

Carcinoma ex-pleomorphic adenoma (Ca ex-PA) is uncommon; however, its accurate diagnosis is important, as the prognosis is better than other salivary gland malignancies, when it is within the pleomorphic adenoma. Fine needle aspiration cytology may be used for its diagnosis. Smears of five cases of Ca ex-PA diagnosed on fine-needle aspiration (FNA) and confirmed on histopathology were analyzed and diagnostic features were assessed. All cases had history of long-standing masses with recent increase in size. Smears showed high grade carcinoma with differential diagnoses of mucoepidermoid carcinoma, adenocarcinoma NOS and salivary duct carcinoma. Features suggestive of PA origin included chondromyxoid stroma: Benign epithelial cells and scattered plasmacytoid cells. The overall agreement between cytological findings and histopathological diagnosis was 100%. Diagnosis of Ca ex-PA may be possible on FNA by correlation with clinical history and detection of chondromyxoid stroma and benign myo-epithelial cells.