Unusual clinical presentation of cutaneous malignant melanoma metastatic to the parotid gland; initially discovered by fine needle aspiration: case report and review of literature.

摘要

We report a case of malignant melanoma (MM) metastatic to the parotid gland, initially discovered on fine needle aspiration (FNA). The patient presented with a mass in the parotid gland area with previous history only significant for prostatic carcinoma. The initial FNA impression was melanoma. The smears were hypercellular with bloody necrotic background. The cells were epithelioid with mild nuclear atypia. Discrete cytoplasmic pigmentation was seen. No lymphoglandular bodies were noticed. Fragments of benign salivary gland were also identified. The cytological diagnosis of MM triggered onsite thorough physical examination for potential primary, where a scalp pigmented lesion was discovered hidden by overlying covering hair. Our differential diagnosis included melanoma, metastatic carcinoma, and lymphoma. Further work up for melanoma with S100, HMB45, and Mart 1 confirmed our top differential diagnosis. We emphasize thorough physical examination in such circumstances, and the importance of onsite evaluation guiding clinicians looking for primary.