Vascular anomalies comprise a spectrum of lesions subdivided into malformations and tumors by clinical behavior and histological features. Vascular malformations demonstrate slow progression, while vascular tumors proliferate rapidly with marked endothelial turnover (Enjolras et al., 2007). Definitive diagnosis can be challenging, as lesion characteristics may not conform to existing classifications. Hence, many vascular anomalies are identified descriptively (Enjolras et al., 2007).“Lobular capillary hemangioma,” describes a vascular tumor with lobular architecture, including infantile hemangiomas and other vascular lesions with lobules of proliferating endothelial cells, although the term is commonly used interchangeably for pyogenic granuloma (PG)(Enjolras et al., 2007). PGs are benign, spontaneous vascular tumors with small vessels organized in lobules (Giblin et al., 2007). Approximately 0.5% of skin nodules and 10% of head and neck hemangiomas are PGs, which often develop in children and adolescents and up to 5% of pregnant women, though rare congenital, disseminated cases occur (Browning et al., 2009; Giblin et al., 2007). Lesions appear as dome-shaped, bright red or blue protrusions that grow rapidly and are prone to hemorrhage (Enjolras et al., 2007). PGs primarily occur on cutaneous or mucosal surfaces of the head, neck, and upper extremities, although cases within the gastrointestinal tract, urinary tract, eye, and the central nervous system have been reported

Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www. nature. com/authors/editorial_policies/license. html# terms Correspondence: Keith A. Choate, MD, Ph. D. Departments of Dermatology, Pathology, and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06519 USA, keith. choate@ yale. edu.* These authors contributed equally to this work.