Carcinoma ex pleomorphic adenoma containing two cancerous components: two case reports

Carcinoma ex pleomorphic adenoma (CXPA) is a rare epithelial malignancy arising from benign pleomorphic adenoma. Cases with two distinct malignant components are exceedingly rare. Nonspecific clinical and imaging features and heterogeneous histology hinder differentiation from other salivary gland tumors, risking misdiagnosis and suboptimal therapy. We report two CXPA cases with dual malignant components and review the literature. Diagnosis relied on histopathology, immunohistochemistry, special stains, and fluorescence in situ hybridization (FISH); both cases showed two malignant components. Histopathology with IHC and FISH was essential, revealing morphological diversity and diagnostic complexity. Literature review confirms rarity and the inadequacy of preoperative clinical and radiological evaluation alone for distinction. Dual-malignant CXPA is a rare diagnostic challenge. Our observations may aid clinicians in reducing misdiagnosis and guiding management.