Splenic Hemangioma
A splenic hemangioma is a benign mass of abnormal blood vessels within the spleen. It is the most common benign tumor of the spleen and is almost always discovered incidentally on abdominal imaging done for other reasons. Most splenic hemangiomas are small, stable, and cause no symptoms throughout life. Larger or atypical lesions are occasionally associated with discomfort or, very rarely, complications such as rupture. Ultrasound, CT, and MRI are the central tools for diagnosis, and most splenic hemangiomas can be confidently identified by their characteristic imaging features without the need for biopsy.
What is it?
A splenic hemangioma is a benign growth in the spleen made up of a tangle of abnormal, dilated blood vessels lined by normal-appearing cells. The vessels form blood-filled spaces (often described as “cavernous” because of their large cavities) separated by thin fibrous walls. Splenic hemangiomas are not cancers, do not spread to other parts of the body, and the great majority remain stable throughout life. They are the most common benign tumor of the spleen and one of the more frequently encountered incidental findings on abdominal imaging.
Splenic hemangiomas are generally thought to be congenital, meaning the abnormal vascular tissue is present from birth, even when the lesion is not detected until adulthood. They can occur anywhere in the spleen, may be single or multiple, and vary widely in size—from a few millimeters to occasional large lesions measuring more than 5 to 10 centimeters. Most are small. Larger lesions are sometimes called “giant” hemangiomas and may be associated with more pronounced findings on imaging or examination.
Most splenic hemangiomas cause no symptoms and are discovered incidentally on ultrasound, CT, or MRI performed for other reasons. Small, asymptomatic hemangiomas are typically managed with reassurance, and most do not require any specific follow-up once the diagnosis is confidently established. Larger hemangiomas occasionally produce vague upper left abdominal discomfort or fullness, particularly when they contribute to overall splenic enlargement. Very rarely, large splenic hemangiomas can be associated with complications such as low platelet counts and bleeding tendency (in a syndrome similar to Kasabach-Merritt phenomenon, which is more often associated with a different vascular tumor) or with bleeding or rupture, particularly after abdominal trauma. Some patients are diagnosed with multiple splenic hemangiomas as part of broader syndromic conditions involving hemangiomas in other organs.
Diagnosis is usually based on characteristic imaging findings rather than biopsy. On ultrasound, small splenic hemangiomas often appear as well-defined, bright (hyperechoic) lesions. On contrast-enhanced CT and MRI, hemangiomas typically show distinctive patterns of contrast enhancement, often with peripheral nodular enhancement that progressively fills in toward the center over time, similar to the classic appearance of hepatic hemangiomas. MRI with contrast provides excellent characterization and is particularly useful when the diagnosis is not clear on other imaging. These findings allow most splenic hemangiomas to be diagnosed confidently with imaging alone. Biopsy is generally avoided because the spleen is highly vascular and biopsy of a hemangioma carries a real risk of bleeding; it is reserved for highly selected unusual cases—such as atypical imaging appearance, patients with a known cancer in whom metastatic disease must be excluded, or persistent diagnostic uncertainty—and is performed only by experienced teams when truly necessary.
Important to Know
For the great majority of patients with splenic hemangiomas, no specific treatment is needed. Once the diagnosis is confidently established by imaging, most hemangiomas can be managed with simple reassurance. Many small, stable hemangiomas do not require any specific follow-up, while larger or less typical lesions may be monitored with periodic imaging for a defined time to confirm stability.
Lifestyle changes are generally not needed for typical splenic hemangiomas. Patients can usually maintain normal diet, exercise, and activity levels without restriction. There is no need to avoid specific foods solely because of a splenic hemangioma, although general healthy habits remain important for overall health.
Treatment is considered only in selected situations. These typically include hemangiomas that cause significant and persistent symptoms not explained by other conditions; rapidly enlarging lesions; complications such as bleeding within the lesion, coagulopathy from very large hemangiomas, or rupture; rare diagnostic uncertainty that cannot be resolved with imaging alone; and—in selected patients—lesions whose size and location create a meaningful concern for future complications. When treatment is needed, spleen-preserving approaches are preferred whenever feasible because of the spleen’s important immune functions. Options include partial splenectomy, lesion resection, or—in selected cases—catheter-based interventional treatments. Total splenectomy is reserved for situations in which spleen-preserving approaches are not feasible, such as very large, centrally located lesions, significant bleeding or coagulopathy, or other specific scenarios. Treatment decisions are individualized and best made in coordination with hepatobiliary or general surgeons, interventional radiologists, and—when relevant—hematology.
Patients undergoing total or partial splenectomy require specific attention to infection prevention. This includes vaccinations against encapsulated bacteria (such as pneumococcal, meningococcal, and Haemophilus influenzae type b vaccines), antibiotic prophylaxis in selected patients, education about prompt evaluation of fevers, and consideration of travel-related risks.
Patients who are pregnant or considering pregnancy, who are taking estrogen-containing medications, or who participate in contact sports occasionally ask whether a hemangioma changes their plans. The vast majority of typical splenic hemangiomas remain stable during pregnancy and with hormonal therapy. Activity restrictions are generally only considered in rare cases of very large hemangiomas where rupture risk is a meaningful concern, and such decisions are individualized.
Care is typically coordinated by primary care clinicians and, when needed, radiologists, hematologists, hepatobiliary or general surgeons, gastroenterologists, and interventional radiologists. Imaging findings are interpreted alongside the patient’s symptoms, examination, and broader clinical context rather than in isolation.
Although a splenic hemangioma is almost always a benign and asymptomatic finding, any new abdominal symptoms should be evaluated based on their own clinical features rather than automatically attributed to a previously identified hemangioma.
Red flag symptoms include sudden severe upper left abdominal pain (especially after trauma to the abdomen), lightheadedness or fainting, rapid heart rate, cool clammy skin or signs of shock, severe fatigue with bleeding or significant bruising, severe vomiting with abdominal pain, sudden severe shortness of breath, or signs of severe infection. These warrant prompt or urgent medical evaluation, as they may indicate complications such as bleeding, rupture, or another serious abdominal condition.