P17 Distinguishing familial generalized multiple glomangiomas from blue rubber bleb naevus syndrome: a case discussion.

Abstract

A 14-year-old, boy was referred with three mildly tender, blue papulonodular vascular lesions located on his left knee, right flank, and left scapula. The lesions on his knee and flank had been present since birth, but he reported recent onset of the lesion on his left scapula. His mother and maternal grandfather reported similar lesions on their leg and forehead. The differential diagnosis included blue rubber bleb nevus (BRBN) syndrome. However, a punch biopsy revealed changes consistent with glomangioma: vascular channels surrounded by bland cells with uniform nuclei that, on immunohistochemistry, exhibited diffuse positivity for SMA and Calponin. This, together with the clinical picture, confirmed a diagnosis of familial generalised multiple glomangiomas (FGMG). This case provides an opportunity to compare the similarities and differences between BRBN and FGMG. While BRBN is usually sporadic, autosomal dominant inheritance can occur. In contrast, FGMG is typically autosomal dominant with incomplete penetrance.1 Both conditions share similar clinical features, presenting with multiple, blue vascular papulonodular lesions that are typically congenital but may increase in number and size, particularly during puberty.2 While generally painless, discomfort or pain may be reported.1 Accurate diagnosis is essential because, although lesions in FGMG are typically limited to the skin, BRBN lesions frequently involve extracutaneous sites-most notably the gastrointestinal tract-where they can lead to significant complications such as haemorrhage or intussusception.2 Confirmation of the diagnosis of FGMG enables reassurance for patients and their families and avoids the requirement for endoscopy and life-long follow-up.