A new clinical understanding of porocarcinoma

Summary: Abstract Body: This study aims to assess the clinical experience and outcomes in managing porocarcinoma, a rare form of skin cancer arising from cutaneous intraepidermal ducts of eccrine sweat glands, historically regarded as an aggressive cutaneous malignancy. A retrospective review of patients treated at UVA diagnosed with porocarcinoma from 2001 to 2024 was conducted with data retrieved from electronic medical records. Sex, age, race, tumor location, size, immunosuppression status, treatments, overall survival rates, recurrence-free survival rates, and disease-specific survival rates were examined. We identified 32 patients diagnosed with porocarcinoma, comprising 19 males and 13 females. Following diagnosis, one patient declined treatment, and two were lost to follow-up, leaving 29 treated patients. At presentation, 7% (2/29) presented with preoperative regional lymph node metastasis. Both patients received wide local excision (WLE) followed by radiation therapy. Among the total cohort, 17% underwent Mohs micrographic surgery alone, and 62% received WLE only. 21% received additional therapies: 14% underwent radiation therapy after surgery, 3% received radiation therapy followed by immunotherapy, and 3% opted for no treatment. Five patients underwent sentinel lymph node biopsy, with one testing positive for metastasis. During follow-up, 10% (3/29) experienced local disease recurrence, and 3% had regional lymph node and distal metastasis. Among those with recurrence, the two patients with local recurrence (67%) were treated with WLE, and the patient with more aggressive disease (33%) received radiation therapy followed by immunotherapy. The overall recurrence-free rate was 90%, with a median follow-up duration of 40 months. Although porocarcinoma has traditionally been regarded as an aggressive disease, our cohort exhibited low rates of short-term recurrence and metastasis. These findings challenge the current perception of the disease and underscore the need for further research to refine clinical approaches and enhance our understanding of porocarcinoma. Margaret Mercante¹, Emily Tocco¹, Russell Witt² 1. University of Virginia School of Medicine, Charlottesville, VA, United States. 2. Department of Surgery, University of Virginia, Charlottesville, VA, United States. Clinical Research: Epidemiology and Observational Research