Arteriovenous Malformation Underlying a Plexiform Neurofibroma: An Unusual Presentation

Abstract

Vascular abnormalities associated with neurofibromatosis type 1 are well described in the literature, however, arteriovenous malformation is a very rare finding in neurofibromatosis type 1. We report the case of an 11-year-old girl who presented with a soft mass on the right flank. Provisional diagnosis of plexiform neurofibroma was made on the basis of clinical and histological observations. Because the lesion was warm on palpation, imaging studies were performed to evaluate further and arteriovenous malformation was detected underlying the plexiform neurofibroma. This report emphasizes the importance of careful examination and proper investigations of the plexiform neurofibroma prior to treatment strategies to avoid future complications. The rarity of plexiform neurofibroma in association with arteriovenous malformation at the same site was also highlighted in this report.

Keywords: Arteriovenous malformation; hypervascularity; neurofibromatosis; plexiform.

Figure 1

Plexiform neurofibroma overlying arteriovenous malformation on the right flank. Café-au-lait macules are also seen

Figure 2

(a) Well-circumscribed collections of spindle cells in the dermis with wavy nuclei within eosinophilic stroma. Focal areas of myxoid changes with increased number of mast cells were also seen consistent with neurofibroma; (b) many large thick-walled blood vessels, proliferating capillaries, and organized thrombi compatible with AVM (H and E staining, ×20)

Figure 3

T2-weighted magnetic resonance imaging showing a heterosignal subcutaneous mass lesion with diameter 83 × 60 mm. Extension to midline is seen due to vascular lesion of arteriovenous malformation