A systematic review of periungual eccrine neoplasms.

Eccrine tumors are a rare cutaneous adnexal neoplasm originating from the sweat glands. The periungual region represents an uncommon localization for these neoplasms. We analyzed all published demographic, clinical, and treatment data on periungual eccrine tumors. A systematic review following PRISMA guidelines was performed of articles published prior to March 2021. Articles were included in the review if a full-text English version was available. Of the surveyed literature, 27 full-text case reports were included in the final analysis. Benign eccrine poroma and porocarcinoma were the most common tumor subtypes (nine and eight cases, respectively). Males were only affected by poroma and porocarcinoma, while females were affected by all tumor subtypes. The first toe was the most common lower extremity affected. Misdiagnosis led to delayed treatment in 25% of cases. As such, while periungual eccrine neoplasms are rare diagnoses, the nonspecific presentations of these growths raise concerns about misdiagnosis and delayed treatment. Further research is needed related to sex-differences in the epidemiology of these growths and into the prevalence of the first toe as a location. These tumors should be considered in the differential diagnosis for nail unit afflictions.