Eccrine Porocarcinoma: New Insights and a Systematic Review of the Literature

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm with high potential for morbidity and mortality. Due to its rarity, there is a paucity of data profiling diagnosis, work-up, and management.

OBJECTIVE

To consolidate reported information on demographics, diagnostics, clinical behavior, treatment modalities, and patient outcomes in EPC to provide a reference tool to optimize diagnosis and management.

METHODS

A comprehensive PubMed search was performed from 1963 to November 2017 using PRISMA guidelines. This yielded 155 articles detailing 206 cases of porocarcinoma.

RESULTS

Eccrine porocarcinoma most often presents in elderly patients on the head and neck or lower limbs. Metastatic disease at presentation is not uncommon (22%). Primary tumor location is significantly correlated with presence of metastasis (p = .038). The most common treatment is excision followed by Mohs micrographic surgery (MMS), although the outcomes after MMS were superior to those after surgical excision.

CONCLUSION

This systematic review of individual patient data reveals that all patients should have a histological diagnosis with imaging considered for high-risk cases. Primary tumor location should also be considered in diagnostic and therapeutic decision-making. Although wide local excision (WLE) is currently the first-line treatment, MMS is becoming increasingly used, with evidence indicating improved outcomes as compared to those seen with WLE.

Malignant Eccrine Porocarcinoma in Finland During 2007 to 2017

Malignant eccrine porocarcinoma is a rare skin adnexal cancer arising from the sweat glands. Little is known about the epidemiology and incidence of eccrine porocarcinoma. This registry-based study examined the epidemiology and incidence data for eccrine porocarcinoma from the Finnish Cancer Registry. The study included all persons diagnosed with eccrine porocarcinoma in 2007 to 2017. There were 69 cases in the study period; 34 (49%) male and 35 (51%) female patients. Mean age at diagnosis was 75.5 years. Incidence for men was 0.06 per 100,000 person-years and for women 0.04 per 100,000 person-years adjusted for age according to the World Standard Population. Incidence increased with age. There was one eccrine porocarcinoma-specific death among the 69 patients. The incidence of eccrine porocarcinoma in Finland is therefore low. The mean age at time of diagnosis and the location of eccrine porocarcinoma are consistent with previous reports. The survival of patients with eccrine porocarcinoma is high.