Metastases to the Parotid Gland: Study from a Tertiary Care Centre.

BACKGROUND: Metastases account for 6-25% of parotid tumors, often presenting dilemmas in their diagnosis. METHODS: Parotid metastases diagnosed on histology/cytology were retrieved. MUC2, MUC5AC, androgen receptor immunohistochemistry was performed in select cases. RESULTS: Fifty-one samples were identified from 42 patients, including 14 aspirates, 7 biopsies and 30 parotidectomies. Previous history was available in 17 cases, 13 parotidectomies accompanied excision of the primary, and relevant clinical data was unavailable for 12 patients. Majority (81%) had head and neck primaries; eye and ocular adnexa were the commonest subsite (52.4%), and sebaceous carcinoma the commonest histology (33%). When history was unavailable, most metastases were initially diagnosed as poorly differentiated carcinoma/malignant tumor, or mucoepidermoid carcinoma on cytology. CONCLUSIONS: Intraparotid metastases encompass a wide spectrum, often mimicking primary salivary gland neoplasms, particularly on limited samples. Metastases should be considered when histological/cytological features are unusual; detailed clinical information and ancillary techniques aid in arriving at an accurate diagnosis.