OP5: Eccrine Porocarcinoma: Experience of Sentinel Lymph Node Biopsy in Case Series of 14 Patients in Finland

Abstract

INTRODUCTION: Eccrine porocarcinoma (EPC) is a rare malignant sweat gland tumour. Lymph node involvement is reported in 17-54% [1-3] of the cases. There are only few case series reporting the use of sentinel lymph node biopsy (SLNB) [2-4]. MATERIALS AND METHODS: This was a retrospective study including all patients treated with EPC in Helsinki University Hospital in 2000-2016. Medical records were reviewed in detail and all the histological samples re-evaluated. RESULTS: 14 patients were treated with EPC. At initial evaluation two patients had lymph node metastases and one tumour was a recurrence. SLNB was done in six patients. There were no positive sentinel lymph nodes. The primary tumour was treated with wide local excision. Two patients had lymph node dissections and one received adjuvant radiotherapy. There were no further recurrences or metastasis in follow-up (mean 8.4 years). Three patients died of unknown causes. At histological evaluation, the mean depth of invasion was 6.5 mm and the mean number of mitoses 3/mm2. There was no lymphovascular invasion. CONCLUSION: EPC might not behave as aggressively as previously reported. The role of SNLB in EPC warrants further studies.