Primary malignant melanoma: a rare cause of mediastinal mass.

A case of primary malignant melanoma in the mediastinum presenting as recurrent laryngeal nerve palsy is reported. Tissue biopsy at mediastinotomy yielded a diagnosis of malignant melanoma. The mass was fixed to the left aspect of the trachea and to the upper border of the left main bronchus and could not be removed surgically. Further extensive clinical and radiological investigations revealed no evidence of tumor elsewhere in the body.