Intramuscular sinusoidal hemangioma with Masson's lesion
A 20-year-old male patient presented with a chief complaint of swelling below the chin since 5 days. On extraoral examination, the swelling was located in the external submental and submandibular region extending from symphysis up to 1 cm superior to the thyroid cartilage. The swelling was ovoid, soft and compressible with well-defined margins, which moved on deglutition.\nThe mandibular occlusal radiograph showed a radiopaque mass in relation to submandibular duct indicative of sialolith.\nBased on the clinical and radiographic appearance a provisional diagnosis of an obstructive salivary gland pathology was given.\nOn grossing, the cut-surface of the specimen consisted of blood filled spaces with multiple septae and two calcified masses.\nMicroscopically, connective tissue stroma with numerous skeletal muscle bundles was seen. In between the skeletal muscle bands, large dilated vascular spaces were seen lined by endothelial cells [Figures –]. Areas of proliferating endothelial cells were seen []. The vascular spaces were sinusoidal and in some areas surrounded by smooth muscle cells. Few areas showed numerous papillary projections in an organizing thrombus within a vessel wall indicative of Masson's lesion [Figures and ]. Extravasated red blood cells were present in the sinusoidal spaces in few areas. Few arterioles, adipose tissue and numerous normal skeletal muscle bundles (in transverse and longitudinal sections) were seen.