Hemangioma is the most common benign liver tumor, with the prevalence (estimated from autopsy series) ranging from 3% to 20%. The majority are diagnosed in middle-aged women, and there is a female-to-male ratio of 5 to 6:1. The pathogenesis of hemangiomas is poorly understood. They are thought to represent hamartomatous outgrowths of endothelium rather than true neoplasms. Some of these tumors express estrogen receptors, and accelerated growth has been associated with high-estrogen states, such as puberty, pregnancy, and when oral contraceptives and androgens are used.
Symptoms Hemangioma of Liver
Most hemangiomas are asymptomatic and are identified incidentally during imaging examinations for unrelated reasons. Patients with large lesions (>5 cm) occasionally complain of nonspecific abdominal symptoms such as upper abdominal fullness or vague abdominal pain. Intermittent symptoms may occur when there is necrosis, infarction, or thrombosis of the tumor. Life-threatening hemorrhage is extremely uncommon even in large tumors but can be precipitated by needle biopsy. Kasabach-Merritt syndrome is a rare consumptive coagulopathy resulting from sequestration of platelets and clotting factors in a giant hemangioma.
Diagnosis Hemangioma of Liver.
Laboratory abnormalities are rare. Because of the possibility of severe hemorrhage from attempts at biopsy, diagnosis relies on imaging investigations. On ultrasound, hemangiomas appear as well-defined, lobulated, homogeneous, hyperechoic masses, although there may be hypoechoic regions representing hemorrhage, fibrosis, and/or calcification. Compressibility of the lesion is pathognomonic. Ultrasound is highly sensitive but not specific, with an estimated overall accuracy of 70% to 80%. Multiphasic (contrast) computed tomography (CT) scans reveal a low-density area with characteristic peripheral enhancement in the early phase. Subsequently, contrast enhancement progresses toward the center of the lesion until, in the delayed enhanced images, the tumor appears uniformly enhanced. The best imaging study is magnetic resonance imaging (MRI), with specificity and sensitivity approximately 85% and 95%, respectively. These tumors appear bright on T2-weighted images, with a similar pattern of enhancement as seen with multiphasic CT. Single photon emission CT (SPECT) with technetium-labeled red blood cells has similar accuracy to MRI, but only if the lesion is larger than 3 cm and close to the surface. Due to these limitations, SPECT is only used as an adjunctive test. Hemangiomas can also be differentiated from other tumors by tagged red blood cell scan.
Treatment of Hemangioma of Liver
Most hemangiomas are treated safely with observation. Indications for intervention include symptoms, complications, and inability to exclude malignancy. In these select patients, the preferred treatment is surgical extirpation. Hemangiomas can usually be enucleated under vascular control (intermittent Pringle maneuver). Formal anatomic resection (e.g., right hepatectomy) is used when the tumor has largely replaced a distinct anatomic unit. Regression after low-dose radiation therapy or embolization in select cases has been described but should be reserved for large, unresectable lesions or for a patient unfit for surgery. In the very rare case of spontaneous hemorrhage, control with vascular embolization provides temporary help until a definitive operative approach can be safely implemented.