Melanoma PNL2 [PNL2]

PNL2 antibody labels intraepidermal nevi, while the dermal component of compound nevi is largely non-reactive with anti-PNL2. PNL2, MART-1/Melan-A and HMB45 antibodies stain most clear cell sarcoma cells and a few cells in angiomyolipomas and lymphangioleiomyomatosis. Non-melanocytic lesions found to be positive with this marker include PEComas and melanotic schwannoma. Anti-PNL2 is a useful antibody for the identification of melanomas and clear cell sarcomas. Differential diagnosis is aided by the results from a panel of antibodies, including antibodies against HMB45, MART-1, Tyrosinase, and MiTF. The differential diagnosis between benign nevi and malignant melanoma is sometimes difficult, and malignant melanoma may mimic other neoplasms, such as undifferentiated carcinoma, sarcoma or large cell lymphoma. PNL2 is more sensitive for metastatic melanoma (87%) than HMB45 (76%) and MART-1 (82%). A panel of PNL2, S-100 and HMB45 is a highly sensitive and specific marker for mucosal melanoma.