[Case contributed by Khaled Al Saad, MD and Norman Chan, MD FRCP(C), Department of Pathology and Laboratory Medicine of King Fahad National Guard Hospital, Riyadh, SAUDI ARABIA]
The large hepatic mass seen in the abdominal CT scan is a giant cavernous hemangioma. Microscopically, note the large spaces lined by endothelium and separated by thin septae, typical for a cavernous pattern of hemangioma. Small hepatic hemangiomas of 2 cm or less in size are common, but those larger than 4 cm (giant hemangiomas) are rare. The mean diameter of the lesion in reported cases of giant cavernous hemangiomas of the liver is 14 cm. Those larger than 5 cm can be symptomatic and require resection, as in this case. Though not a feature of this case, and more likely to occur in infancy and childhood, some giant hemangiomas can be complicated by coagulopathy. The sequestration of platelets as well as a microangiopathic hemolytic anemia occurring in association with giant hemangioma is known as the Kasabach-Merritt syndrome.