A case of penile melanoma illustrating the low sensitivity of frozen sections in the assessment of sentinel lymph nodes.

A 75 year-old uncircumcised man presented with a 1.1mm thick malignant melanoma on the ventral aspect of the glans penis. He underwent isosulfan blue and technetium 99m guided sentinel lymph node (SLN) biopsy and distal penectomy with 2 cm margins. This is the third reported case of penile melanoma using both markers for SLN mapping. While frozen sections and H& E stains were negative, S-100 and HMB-45 immunohistochemistry revealed micrometastasis in one of the sentinel nodes. This case illustrates that any discussion with the patient about management and prognosis should await immunohistochemistry results.