Abstract
OBJECTIVES: Eccrine porocarcinoma is a rare malignant adnexal tumor derived from the eccrine sweat glands, with metastatic potential. It primarily affects elderly individuals, and its most common location is in the head and neck region. Clinically, it presents as a solitary, nodular, erythematous-violaceous tumor. Its diagnosis can be challenging due to its clinical and histopathological variability. The objective of this case report is to describe a case of eccrine porocarcinoma in an unusual location and analyze its diagnostic and therapeutic approach. CASE REPORT: We present the case of a 59-year-old male patient who sought medical attention due to an asymptomatic lesion on the dorsum of the right foot, evolving over three months. On physical examination, a 1.5 cm diameter tumor with a brownish coloration and lobulated exophytic appearance was observed. Dermoscopy revealed erythematous and whitish areas. An incisional biopsy was performed, and histopathological analysis revealed an in situ porocarcinoma originating from a poroma. Immunohistochemistry confirmed positivity for EMA, CEA, and p63. A complete excision of the lesion was performed, with free margins and no evidence of recurrence to date. CONCLUSION: Eccrine porocarcinoma is a rare cutaneous neoplasm but has aggressive potential. Its diagnosis requires a comprehensive approach based on clinical evaluation, histopathology, and immunohistochemistry. Complete excision with free margins is the treatment of choice, although other therapies may be considered in advanced cases. Periodic follow-up is essential for early detection of recurrences and metastases.