Intravascular pyogenic granuloma arising in an acquired arteriovenous malformation: report of a case and review of the literature.

Background. Pyogenic granuloma, also known as lobular capillary hemangioma, is a benign vascular skin tumor. Intravascular variant of this vascular tumor is rare and such a variant arising in another hemangioma is extremely unusual. Objective. The objective was to present a patient with an intravascular pyogenic granuloma arising in an acquired arteriovenous malformation of the palm. Methods. We report a case and review the literature. Result. A 44-year-old woman presented with an easy-bleeding and ulcerative nodule with a hyperkeratotic collaret on her right palm for 3–4 months. The nodule measured 6 × 6 mm in size and was tender. Under the clinical impression of pyogenic granuloma, the lesion was totally excised and the microscopic examination revealed an intravascular pyogenic granuloma in the papillary dermis with an underlying arteriovenous malformation. Conclusion. A rare composite vascular tumor is reported, and our case presented as a red eroded nodule surrounded by a keratotic collaret, which was easily misdiagnosed as pyogenic granuloma clinically. We suggest that any pyogenic granuloma-like lesion should be palpated carefully, and if a nodule is present, surgical excision rather than cryotherapy or laser ablation should be considered.