Dermoscopic features of hidroacanthoma simplex: Usefulness in distinguishing it from Bowen's disease and seborrheic keratosis

Abstract

Hidroacanthoma simplex (HAS) is a rare benign eccrine adnexal tumor. HAS is sometimes clinically or pathologically misdiagnosed as squamous cell carcinoma in situ (Bowen's disease; BD), seborrheic keratosis (SK) or other adnexal tumor. To date, there has never been a report focusing on dermoscopic features to distinguish HAS from BD and SK. We found the following dermoscopic findings to be characteristic of HAS: fine black dots/globules (75% of cases) and fine scales arranged annularly (100% of cases). In contrast, glomerular vessels, which are typically observed in BD, were not seen in any of the four cases. Cerebriform appearance and milia-like cysts, which are typically observed in SK, were also not seen in any of the four cases. The existence of "scattered fine black dots/globules" and "fine scales arranged annularly", and the absence of the glomerular vessels, may contribute to precise diagnosis of HAS. Even though HAS resembles BD or SK clinically, it can be distinguished from these by the characteristic dermoscopic features.

A dermoscopic pitfall in a long‐standing tumor

“…Die Zellnester bestanden aus kleinen monomorphen basaloiden Zellen (poroiden Zellen), deren Zellkerne kleiner waren als die der umgebenden epidermalen Keratinozyten. Die Zellenansammlungen waren von einigen größeren Zellen mit eosinophilem Zytoplasma [ 5 ] . Die hauptsächlichen Strukturelemente waren schwarze oder braune Punkte/Globuli, ein fehlendes Pigmentnetzwerk und meist anulär ausgerichtete feine Schuppen.…”

Clinical, dermoscopic, and histopathologic findings of hidroacanthoma simplex: Literature review and case report

“…Hidroacanthoma simplex (HS) is a rare intraepidermal benign tumor in the acrosyringeal portion of the eccrine duct [1][2][3][4][5][6][7][8][9] . HS is frequently found on the lower limbs and trunk, and the lesions present as a flat brownish or verrucous plaque [1][2][3][4] .…”

“…HS is frequently found on the lower limbs and trunk, and the lesions present as a flat brownish or verrucous plaque [1][2][3][4] . Its clinical diagnosis is often confused with squamous cell carcinoma "in situ" (Bowen's disease; BD), seborrheic keratosis (SK), or another adnexal tumor [1][2][3][4][5][6][7][8][9] .…”

“…Small black globules and fine scales with annular distribution were described as characteristic of HS. 5,6 Dots vessels are not specific but can be found 5,6 .…”

Cricumscribed and multiple hidroacanthoma simplex

“…reported three main dermoscopic features that characterize hidroacanthoma simplex—(i) scattered fine black dots/globules; (ii) fine scales arranged annularly; and (iii) the absence of the glomerular vessels that are usually observed in Bowen’s disease. [ 3 ] Though rarely reported, hidroacanthoma simplex can develop porocarcinoma. Anzai et al .…”