Subungual Eccrine Poroma: An Unusual Location.

Introduction: Eccrine poroma is a rare benign adnexal tumor that originates from the acrosyringium of eccrine sweat ducts, typically found on palms and soles. Its occurrence in subungual location is rare, making diagnosis and treatment challenging. We present the details of subungual eccrine poroma, emphasizing its unusual presentation, dermoscopic features, and management.

Case presentation: A 36-year-old female presented with a slowly growing, asymptomatic, reddish subungual mass under the left index finger nail for the past 5 years. Onychoscopy showed a reddish-pink homogenous area with keratotic borders, reddish globules, and dotted vessels. An excisional biopsy was done, and a final diagnosis of eccrine poroma was made on histopathology, with no recurrence over 6 months of follow-up.

Conclusion: Given the rarity of subungual involvement, our case highlights the importance of considering eccrine poroma in the differential diagnosis of subungual tumors. Onychoscopy can aid in diagnosis and differentiation from other subungual masses, though a definitive diagnosis requires histopathology.