Splenic Pathology: Splenic Hemangioma |
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Hemangiomas are the most common primary tumor of the spleen with a prevalence
of 0.03-14%. This is a congenital lesion arising from sinusoidal epithelium
resulting from proliferation of vascular channels lined by a single layer
of endothelium, most often resulting in a cavernous lesion.
Hemagiomas are variable in size ranging from a few millimeters to several centimeters. The majority are less than 4 cm, but there are reports of lesions up to 17 cm. Hemangiomas may be single or multiple as in Klippel-Trenauney-Weber syndrome. On noncontrast CT hemangioma are either hypodense or isodense to the spleen. Following injection of intravenous contrast, these tumors may remain hypodense, but exhibit peripheral enhancement. However, the typical filling-in seen with hepatic hemangiomas is not necessarily the rule with splenic hemangiomas. These lesions tend to be well circumscribed and may contain either central punctate calcifications or peripheral curvilinear calcifications of cystic regions. The
majority of hemangiomas are asymptomatic and incidentally discovered.
However, larger lesions may enlarge the spleen leading to fullness and
left upper quadrant discomfort. Complications consist of spontaneous
splenic rupture in 25% of cases. Kasabach-Merritt is a syndrome reported
in patients with large hemangiomas. These patients develop anemia, thrombocytopenia,
and coagulopathy with multiple hemangiomas throughout the body, but
predominately in the lung and liver. The multiple hemangiomas can lead
to massive shunting and cardiac failure. Management consists of embolization
to decreased shunting and control the consumptive coagulopathy in individuals
with severe Kasabach-Merritt syndrome. |