SINUSOIDAL HEMANGIOMA

Introduction. Sinusoidai hemangioma (SH) was described by two patholog ists, Calonje and Fletcher, in 1991. This uncommon cutaneous benign va scular lesion with distinctive histologic features was considered a su bset of lesions known as << cavernous hemangiomas >>. It is made of di lated interconnecting (<< sinusoidal >>), thin-walled channels with a single-layered lining endothelium and a lobular architecture. Patients and methods. Clinical, radiological (CT, MRI and arteriography), evol utive, and histologic data of 4 patients, whose lesions appeared very similar clinically and histologically, were reviewed and compared to t he patterns of the so-called SH. Results. There were 2 males and 2 fem ales. Lesions had an infantile onset in 3 (congenital in 2). They exhi bited a protracted course over years in the 4, and they all invaded th e right forehead, eyelids and orbit areas. Clinically, they appeared a s multilobulated, buldging, firm tumors under a normal shiny skin. Rad iologically, lesions were strikingly nodular, with criteria of slow-fl ow vascular lesions on MRI and arteriograms. Histologically, all lesio ns were comprised of well circumscribed nodules with a lobulated archi tecture, made of greatly dilated, blood-filled, thin-walled vascular c hannels, with scanty fibrous stroma between them. Interconnecting chan nels had the distinctive sinusoidal pattern. There were some elongated pseudopapillary structures. Islands of spindle cells were noted in 2 lesions. Discussion. On the one hand histologic features of the lesion s in our 4 patients are identical to those described by Calonje and Fl etcher as SH, a lesion not to be confused with classic, involuting - t ype, hemangioma of infancy and childhood, and with venous or lymphatic malformations of the same location. SH fits into the group of lesions defined by pathologists as << cavernous hemangiomas >>. On the other hand the lesions in our 4 patients differed from the clinical descript ion of SH as a solitary acquired small (less than 3 cm) nodule in adul ts. Otherwise the four lesions described herein constitute a distincti ve clinicopathologic entity with a striking aggressive local growth al though there is a histologic malformative pattern. The presence in 2 c ases of islands of spindle cells led us to discuss the differences wit h spindle cell hemangioendothelioma.