Two Cases of Scalp Eccrine Porocarcinoma with Review of Literature

Eccrine Porocarcinoma (EPC) is a rare malignant adnexal neoplasm arising from the eccrine sweat glands. Head and neck, lower extremities are the most common primary locations for the development of EPC. Scalp is a rare site of involvement, with less than 20 cases reported so far. This study aims to report two cases of scalp EPC, which showed different clinical courses that could be predicted by histopathologic features. In one case, a 62-year-old woman with EPC was treated by local excision with 30 mm margin. A mitotic count of 16/10 high-power field, invasion depth >7 mm, and infiltrative tumor margins were observed, which are suggested as poor prognostic factors. Pulmonary metastasis and local recurrence occurred rapidly after 4 months of disease-free interval. In the other case, local excision with 10 mm margin was performed in a 45-year-old woman with EPC. Poor prognostic histopathologic features were absent, and there was no evidence of the disease during the 2-year follow-up period.