Agminated cellular blue naevi of the penis: dermoscopic, confocal and histopathological correlation of two cases

Abstract

Blue naevi may present rarely as multiple lesions grouped in a circumscribed area, described as agminated blue naevi. This clinical presentation may mimic metastatic malignant melanoma. We present two cases of agminated cellular blue naevi of the penis, with dermoscopy, reflectance confocal microscopy and histopathological correlation. Dermoscopy of the area showed multiple grouped lesions of homogeneous dark-brown to blue colour. Using reflectance confocal microscopy, focusing on the bluish areas, predominantly bright dendritic cells were visible at the dermoepidermal junction and papillary dermis, while in the brownish areas the presence of dendritic and bright cells predominated in the basal layer. Our patients are of special interest as they are the first cases, to our knowledge, reported of agminated blue naevi on the penis, studied by both dermoscopy and confocal microscopy, confirming the diagnosis with histopathological correlation. Moreover, one case represented a divided or 'kissing' blue naevus of the penis.

Agminated segmental plaque‐type blue nevus associated with hypertrichosis and soft tissue hypertrophy: Report of a case and review of the literature

“…The aggregation of melanocytes around appendages and neurovascular bundles is also commonly seen in BN. In our case, we found diffuse dermal melanocytosis, without the characteristic dendritic melanocytes of a single BN, within the dermis, which is consistent with findings reported in some of the previous cases of ABN …”

“…ABN is a rare entity that clinically may be similar in appearance to nevus spilus or juvenile melanoma, although the histology is usually consistent with common BN . Lesions most commonly occur on the limbs, although other locations such as the temples have also been described . Upshaw and colleagues reported the first case of a PTBN on the thorax of a 9‐year‐old boy .…”

Multiple pigmented lesions of the glans penis after circumcision

“…In conclusion, we suggest that if multiple eruptive pigmented lesions resembling BN are present, a biopsy should always be performed for a differential diagnosis with malignant or metastatic melanoma [ 1,3,[8][9][10][11] .…”

“…Eruptive blue nevi (EBN) have rarely been described [ 2,[5][6][7][8][9][10][11] . De Giorgi and colleagues [ 1 ] reported a case of EBN of the penis in an adult patient.…”

Agminated blue nevus with a GNAQ mutation: A case report and review of the literature

“…3 Since then, over 30 cases have been reported in the literature (Supporting Information Table S1). [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Unlike sporadic or common BN, which have a clinical predilection for certain anatomic sites, agminated BN present equally on the trunk, extremities, and head/neck. A review of the 31 cases published since 1990 showed that 9 were present on the extremities, 10 on the head and neck, 10 on the trunk, and 2 on the genitals (Supporting Information Table S1).…”