A case of advanced eccrine procarcinoma with a transient response to nivolumab

Abstract

An 81－year－old woman presented with multiple erythematous nodules on her right thigh. A skin biopsy suggested either eccrine porocarcinoma or squamous cell carcinoma, and she was referred to our department for further evaluation. Positron emission tomography/computed tomography (PET/CT) revealed multiple lymph node metastases, and she was diagnosed with unresectable stage IV eccrine porocarcinoma. Although chemotherapy was recommended, she was subsequently lost to follow－up. Six months later, she returned with worsening fatigue, and nivolumab therapy was initiated. Following treatment initiation, the skin lesions decreased markedly in size, and the lymph nodes also showed a reduction in size. Although the lesions gradually enlarged after the sixth dose, treatment was continued. The patient died shortly before the ninth dose could be administered. Immune checkpoint inhibitor therapy is generally considered to have limited efficacy in adnexal cancers. Given the temporary response observed in this case, we report it along with a review of the relevant literature.[Skin Cancer (Japan) 2026 ; 41 : 1－6]