Splenic hemangiomas are common findings in medical imaging, and most are benign, posing no serious threat. These vascular tumors are typically discovered by chance during scans for unrelated conditions, meaning they are asymptomatic. However, any abnormal growth requires professional attention and monitoring due to a specific, rare complication that can become life-threatening. Understanding the nature of this growth and the surveillance process helps manage initial concerns.
Defining Splenic Hemangiomas
A splenic hemangioma is a non-cancerous mass formed from an abnormal collection of blood vessels within the spleen. It is the most common type of benign tumor found in this organ, though its incidence is low (estimated between 0.03% and 14% based on autopsy studies). These growths are vascular malformations, consisting of tangled channels, often classified as the cavernous type.
Hemangiomas are thought to be congenital and often grow slowly without causing issues. Because they typically do not produce symptoms, most splenic hemangiomas are discovered incidentally during imaging, such as an ultrasound or CT scan, for an unrelated abdominal complaint. This incidental discovery often causes initial concern, as patients were unaware of the mass.
Assessing the Risk of Rupture
The primary danger associated with a splenic hemangioma is the potential for spontaneous or traumatic rupture, which leads to severe internal bleeding (hemorrhage). Since the spleen is highly vascular, a tear in a large hemangioma can cause a rapid, life-threatening drop in blood pressure and shock. Historically, older medical literature reported rupture in up to 25% of symptomatic cases.
The risk of rupture is correlated with the size of the lesion. Hemangiomas measuring four centimeters or larger carry an increased risk of rupture, prompting a more cautious management approach. Signs of acute rupture include sudden, severe pain in the upper left abdomen that may radiate to the left shoulder, often accompanied by symptoms of shock like dizziness and rapid heart rate. This medical emergency requires immediate surgical intervention to control the hemorrhage.
Diagnosis and Surveillance Protocols
When a mass is first detected, various imaging modalities confirm it is a hemangioma and not a more concerning lesion. An abdominal ultrasound is often the initial screening tool, followed by contrast-enhanced Computed Tomography (CT) scans or Magnetic Resonance Imaging (MRI) for better characterization. These advanced scans help determine the internal structure and precise dimensions of the growth, which informs management decisions.
For small, asymptomatic hemangiomas (typically less than four centimeters), the standard approach is active surveillance. This involves routine follow-up imaging, often a yearly ultrasound or CT scan, to monitor the lesion’s size and stability. The goal of this protocol is to ensure the hemangioma is not growing rapidly or showing internal changes that would increase the risk of rupture. For most patients, monitoring, not immediate intervention, is the safest approach.
Intervention and Long-Term Outlook
Intervention becomes necessary when the hemangioma reaches a significant size (usually over four or five centimeters), exhibits rapid growth, or causes symptoms such as abdominal pain. The presence of symptoms, a high risk of rupture, or diagnostic uncertainty are factors that push the decision toward treatment. The primary treatment option is surgical removal.
Total splenectomy, the removal of the entire spleen, is the most definitive way to eliminate the risk of rupture. However, surgeons increasingly favor a spleen-preserving approach, such as a partial splenectomy, whenever feasible to maintain the spleen’s immune function. Splenic artery embolization, a procedure that blocks the blood supply to the hemangioma, may also be used as a pre-operative measure or as a less invasive option for high-risk patients. Once a symptomatic or large hemangioma is successfully managed, the long-term outlook is excellent.