Clear cell eccrine porocarcinoma with extensive cutaneous metastasis and peripheral lymphocyte dysfunction.

An 81-year-old woman came to our clinic (Department of Dermatology, Kaohsiung Medical University, Kaohsiung, Taiwan) with multiple erythematous, indurated papules over the left side of her face. Two years earlier, the patient had a skin biopsy done at a similar anatomical area with the histopathological diagnosis of Bowen's disease. After reviewing surgical specimens and confirming no systemic involvement, clear cell eccrine porocarcinoma with extensive cutaneous metastasis has been diagnosed. In addition, the peripheral blood lymphocyte function of the patient was evaluated. The expression of interleukin-2 receptors on lymphocytes after stimulation is abnormal compared with the age-matched normal control and a patient with cutaneous squamous cell carcinoma. This clinical manifestation of eccrine porocarcinoma is exceptional, and lymphocyte dysfunction in this patient has probably contributed to extensive cutaneous metastasis.