56 Head and Neck Pathol (2009) 3:54–58 Fig. 2 a Circumscribed swelling on left malar region, b gross specimen with nodular surface and irregular borders, c blood vessels of varying caliber, inﬁltrating into the stroma rich in adipose tissue, d proliferating capillaries around feeder vessel, e canalization and new blood vessel formation, f nerve bundle inﬁltrated by proliferating capillaries Intraoral examination revealed diffuse bony swelling extending from the mandibular right central incisor to second molar and presented with egg shell crackling. All teeth associated with the lesion were mobile. OPG revealed radiolucency extending from mandibular right central incisor to second molar (Fig. 3b). Magnetic resonance imaging (MRI) hard tissue window showed lytic lesion in the medulla of the mandible, with erosion of buccal and lingual cortical plates, thus giving a sun-ray appearance (reactive periostitis). Angiography presented with mild increase in vascularity of the right external carotid artery (Fig. 3c). A provisional diagnosis of AV malformation was considered. Hemimandibulectomy and reconstruction with free iliac crest bone was done. The gross specimen showed areas of dark brown to bluish lesion on both medial and lateral aspect of the mandible. On opening, large vascular chan- nels were seen (Fig. 3d). Fig. 3 a Large diffuse swelling on the right side of the mandible, b panoramic radiograph showing large ill-deﬁned radiolucency extend- ing from 41 to 47, c angiography showing mild increase in vascularity of right external carotid artery, d gross specimen showing large vascular channels inside the body of the mandible, e vascular channels inﬁltrating into the bone, f periosteal inﬁltration Histopathological ﬁndings revealed numerous vascular channels of capillary and cavernous caliber inﬁltrating into the bone (Fig. 3e). Areas of periosteal inﬁltration with reactive new bone formation were also evident (Fig. 3f) and a histopathological diagnosis of angiomatosis was conﬁrmed. Discussion Diffuse form of hemangioma can be described as angio- matosis. It clinically mimics hemangioma or AV malformation [4]. It is also termed as diffuse hemangioma, haemangiomatosis [5] and inﬁltrative hemangioma [6]. The co-existence of vascular proliferation and abundant fat in this inﬁltrating lesion previously inspired the now obsolete term ‘inﬁltrative angiolipoma’ [3]. If only muscles are predominantly involved, it may also be termed as ‘Intra-