The role of reflectance confocal microscopy in a case of Bowen’s disease difficult to diagnose

Abstract

There have been limited reports describing reflectance confocal microscopy (RCM) features of Bowen’s disease (BD). Herein, we describe the RCM features of a pigmented BD with atypical dermoscopic features, mimicking a melanoma. This case highlights the importance of RCM in a challenging BD.

Reflectance Confocal Microscopy of Pigmented Bowen’s Disease: A Case Series of Difficult to Diagnose Lesions

“…These are: presence of atypical honeycomb pattern, atypical keratinocytes of different sizes and shapes, and "button-hole signs" consistent with tortuous blood vessels. A potential diagnostic point of discussion is the presence of numerous bright, large, round or dendritic cells infiltrating the epidermis, as previously observed [7,9]. Recently, three challenging cases of pigmented Bowen's disease were reported and wrongly diagnosed as melanoma due to the high density of dendritic cells observed using RCM [8].…”

“…Reflectance confocal microscopy (RCM) is a noninvasive technique mostly used for differential diagnosis of pigmented, melanocytic and nonmelanocytic skin lesions. To date, few data are available regarding its use in the diagnosis of pBD [7][8][9][10][11].…”

Identifying Pitfalls for Diagnosing Pigmented Bowen Disease on Reflectance Confocal Microscopy: Misleading Dendritic Cells

“…Thus, it is important to visualize DEJ in detail and follicular structures for signs of dendritic cell infiltration to rule out LM. Other clues for pBD are numerous marked small bright rings at DEJ [ 5 , 6 ]. Since DEJ is infiltrated by malignant melanocytes in LM, presence of regularly shaped bright rims can signify pigmented AK/pBD.…”

Bowen’s disease of the penile shaft presenting as a pigmented macule: dermoscopy, reflectance confocal microscopy and histopathological correlation

“…Some studies reported the RCM features of non-genital pigmented Bowen’s disease and their histopathological correlations. 2 , 7 , 8 , 9 They mainly consist of parakeratosis, irregular honeycomb pattern (indicative of keratinocyte atypia and pleomorphism), edged papillae (due to hyperpigmentation of keratinocytes of the basal layer), and coiled vessels in the dermal papillae. Other observed findings are represented by round nucleated cells often with a targetoid appearance throughout the epidermis (corresponding to dyskeratotic keratinocytes), intraepidermal hyperreflective dendritic, spindle-shaped cells (corresponding to Langerhans cells at immunostaining), and plump bright cells in the papillary dermis (corresponding to melanophages).…”

“…Other observed findings are represented by round nucleated cells often with a targetoid appearance throughout the epidermis (corresponding to dyskeratotic keratinocytes), intraepidermal hyperreflective dendritic, spindle-shaped cells (corresponding to Langerhans cells at immunostaining), and plump bright cells in the papillary dermis (corresponding to melanophages). 2 , 7 , 8 , 9 It must be highlighted that the dendritic cells may represent a confounder finding as they may also correspond to atypical melanocytes and could lead to the wrong diagnosis of melanoma, 9 and that the differential diagnosis of melanophages with pigmented cells of Bowen’s disease may not be easy due to the epidermis disruption and tumor cell heavy pigmentation.…”