Eccrine porocarcinoma with extensive cutaneous metastases

Background Eccrine porocarcinoma (EPC) is an uncommon malignant neoplasm that originates in the intraepidermal portion of the eccrine sweat duct. Although porocarcinoma is a slow-growing tumor, up to 20% of cases can metastasize to regional lymph nodes, thus increasing mortality. Methods We describe the clinical and histopathological features and clinical course of three cases of extensive metastatic EPC diagnosed in our department over the last 10 years. Results All three patients were women aged 89–96 years. They had numerous skin tumors on the left leg that were histologically and immunohistochemically diagnosed as metastatic EPC. Only one patient had a history of primary porocarcinoma, which had been excised 6 years earlier. The remaining two patients had a previous lesion diagnosed as squamous cell carcinoma. We treated the patients with palliative radiotherapy and/or chemotherapy. Only one patient is currently alive. Conclusions The cases of cutaneous and regional metastatic EPC we present occurred in elderly women with major involvement of the left leg. The third case is noteworthy, as the patient presented a long latency period before metastases appeared. Difficulties in the clinical diagnosis – and occasionally histological diagnosis – of primary EPC could delay more aggressive treatment, although optimal treatment does not always guarantee a good prognosis.