Sarcoidosis: a cause of bilateral hilar lymphadenopathy after excision of malignant melanoma of the arm.

Bilateral hilar lymphadenopathy developed in a patient one year after excision of a malignant melanoma of the left arm. There were no signs of distant metastases. Hilar lymph node biopsy specimen obtained by mediastinoscopy showed multiple noncaseating granulomas consistent with sarcoidosis, without evidence of tumor cells. Sarcoidosis developing in the course of a preexisting neoplasm is rare, but must be considered in order to establish a proper diagnosis and withhold unnecessary treatment.