Heterotopic SMARCB1-deficient high-grade transformed/dedifferentiated acinic cell carcinoma and sine-qua-non radiology- pathology with TNM challenge

Heterotopic salivary tissue (HSGT) is found where salivary glands are not normally placed. HSGT manifests as accessory salivary glands, salivary tissue associated with branchial cleft anomalies, and true heterotopic salivary gland tissue. Benign and malignant salivary heterotopias have been described in the literature, with the most common reported neoplasm being Warthin tumor. In the malignant group, the most frequent tumors are mucoepidermoid carcinomas (MEC) and acinic cell carcinomas (AciCC). For the treating physician, this condition presents a diagnostic dilemma, whether these salivary heterotopias represent metastasis from orthotopic salivary origin or primary of heterotopic origin.