Pigmented poroid neoplasm mimicking nodular melanoma
Tsuyoshi Mitsuishi, M.D., Ph.D., Department of Dermatology, Nippon Medical School, 1-1-5 Sendagi, Bunkyou-ku, Tokyo 113-8603, Japan. Email: [email protected]
Abstract
We reported the case of a 92-year-old woman with a pigmented and non-pigmented surface of the pedunculated nodule on her lower leg. Microscopic examination revealed that this nodule consisted of a component of small, dark, homogenous, poroid cells and cuticular cells in the dermis. The histopathological features of the lesion were consistent with poroid neoplasm. Immunohistochemistry showed that HMB-45 and Melan-A were positive in malanocytes and melanophages of the pigmented areas. Unlike most poroid neoplasms, this case showed pigmented lesion mimicked nodular melanoma.
