Coexistence of micrometastatic melanoma cells and sarcoid granulomas in all regional lymph nodes in a patient with acral melanoma.

A 68-year-old woman who had been diagnosed with sarcoidosis presented with acral lentiginous melanoma (Breslow's tumour thickness, 2.6 mm; Clark's level IV) on her right heel. She underwent surgery for excision of the primary tumour and sentinel lymph node biopsy. The two sentinel lymph nodes revealed numerous sarcoidal granulomas and small nests of metastatic melanoma cells in the subcapuslar lesions. She subsequently underwent ilio-inguinal lymph node dissection. Surprisingly, all of the nine dissected nodes were mostly replaced by sarcoidal granulomas and contained melanoma micrometastases.