Splenic lesions arise from a surprisingly wide range of causes, including benign growths like cysts and hemangiomas, blood-flow problems that kill patches of tissue, infections that seed abscesses, inflammatory diseases like sarcoidosis, and cancers such as lymphoma. The spleen does not get the same attention as the liver or kidneys, so a lesion found on imaging often catches people off guard. Most splenic lesions turn out to be harmless, but sorting benign from dangerous usually requires careful imaging and sometimes a tissue sample.
Benign Growths Are the Most Common Splenic Lesions
The majority of lesions found incidentally on the spleen are benign. They include cysts, hemangiomas, hamartomas, and a rare entity called sclerosing angiomatoid nodular transformation (SANT).1MDPI Diagnostics / Europe PMC. The Spectrum of Solitary Benign Splenic Lesions-Imaging Clues for a Noninvasive Diagnosis Many of these never cause symptoms and are discovered only because someone had a CT scan or ultrasound for an unrelated reason.
Hemangiomas are the most common benign primary tumor of the spleen. They are made up of abnormally proliferated blood vessels that form spongy, reddish-blue nodules. On imaging, they have a distinctive pattern: they light up brightly on certain MRI sequences and show a characteristic progressive filling with contrast dye, which helps radiologists distinguish them from other lesions.2PubMed Central. Common and Uncommon Splenic Lesions: A Review – Section: 2.8. Hemangioma Most small hemangiomas need no treatment, though larger ones can develop areas of tissue death internally and, rarely, rupture.
Splenic hamartomas are uncommon benign masses made of disorganized but otherwise normal splenic tissue. They often present with vague abdominal discomfort. Because imaging alone cannot always distinguish a hamartoma from something more concerning, spleen removal is sometimes performed both to relieve symptoms and to rule out cancer.3PubMed Central. Hamartoma – a rare benign tumor of the spleen: a report of four cases
Cysts can be either “true” cysts lined with cells or pseudocysts that form after trauma or infection. Imaging can struggle to tell them apart, and sometimes the distinction only becomes clear under a microscope after surgery.4PubMed Central. Symptomatic large epithelial splenic cyst mimicking post-traumatic pseudocyst: a surgical case report Lymphatic malformations of the spleen also exist and can be misread as simple cysts on initial imaging; a clue to the correct diagnosis is that these malformations tend to be multicystic with mild internal enhancement on contrast studies.5PubMed Central. A case series of radiologically misdiagnosed visceral lymphatic malformations
SANT is a rare, benign vascular lesion of the spleen that can look worrisome on a scan. In children, a well-defined solid splenic mass may turn out to be SANT even when the classic imaging pattern is absent. Because the condition is harmless, some researchers are exploring whether a needle biopsy confirming SANT could spare patients from having the spleen removed entirely, though that approach still needs broader study.6PubMed Central. Imaging and pathological features of pediatric sclerosing angiomatoid nodular transformation of the spleen: a case series and hypothesis-generating perspective on non-operative management
Splenic Infarction and Other Vascular Problems
When blood flow to a section of the spleen is blocked, the tissue dies, creating an infarct. Splenic infarction causes sharp left-sided or upper abdominal pain and is sometimes mistaken for other acute abdominal conditions. The underlying cause is either reduced arterial flow or a blood clot, and these two mechanisms often overlap in the same patient.
Blood disorders that crowd the spleen’s circulation with abnormal cells or promote clotting account for most cases. Conditions like chronic myeloid leukemia, particularly when white-cell or platelet counts are extremely high, create a prothrombotic state that raises the risk of splenic infarction.7PubMed Central. Splenic Infarction at the Crossroads of Hematologic and Cardioembolic Risk Heart conditions that throw off blood clots, especially atrial fibrillation, are another well-recognized trigger. Splenic infarction can also follow cardiovascular surgery, autoimmune diseases, and infections.8Turkish Journal of Emergency Medicine. A Rare Cause of Acute Abdominal Pain: Splenic Infarct (Case Series)
A large study of adults with splenic infarction found that the picture is more complicated than textbooks typically suggest. In about 40% of cases, more than one plausible predisposing condition was present. Abdominal problems like pancreatic disease and sepsis were common co-factors, likely because inflammation and infection promote clotting on their own. The study also highlighted atherosclerosis of the splenic artery as an underappreciated contributor: roughly one in five patients had fatty plaques narrowing the artery that feeds the spleen, which may lower the threshold for infarction when even mild clotting abnormalities are present.9JAMA Internal Medicine. Assessment of Clinical Conditions Associated With Splenic Infarction in Adult Patients
Infections That Target the Spleen
The spleen filters blood and traps bacteria, which makes it both a first line of defense and a potential site for infection to take hold. Splenic abscesses can form when bacteria circulating in the bloodstream settle in splenic tissue, particularly in areas already damaged by infarction. This mechanism is especially relevant in people with infective endocarditis, a bacterial infection of the heart valves: infected material from the heart valves can embolize to the spleen, seeding an infarct zone that then develops into an abscess.10PubMed Central. Splenic abscess associated with infective endocarditis; Case series Clinicians caring for patients with endocarditis and evidence of splenic blood-clot damage are advised to watch for abscess development.11PubMed. Splenic abscess and infective endocarditis
In people with weakened immune systems, particularly children receiving chemotherapy, multiple tiny abscesses scattered throughout the spleen strongly suggest a fungal infection. Candida and Aspergillus are the fungi most often responsible.12PubMed. Splenic microabscesses in the immune-compromised patient These microabscesses can be difficult to treat and sometimes persist even with appropriate antifungal therapy.
In parts of the world where the tapeworm Echinococcus granulosus is common, parasitic hydatid cysts can form in the spleen. The liver and lungs are by far the most frequent sites for these cysts, and isolated splenic involvement accounts for less than 2% of cases.13PubMed Central. Albendazole Monotherapy and Spleen Preservation in an Adolescent with Isolated Primary Splenic Cystic Echinococcosis: A Case Report However, a hydatid cyst can look identical to a simple cyst on imaging and may lack the classic blood-test markers. Because rupture of a hydatid cyst can trigger life-threatening allergic shock, clinicians in areas where the parasite circulates are urged to keep it on the list of possibilities whenever a cystic splenic lesion appears, especially in patients from rural backgrounds.14PubMed Central. Hydatid cyst of spleen: a diagnostic challenge15PubMed Central. Hydatid Cyst of Spleen Presenting with Vague Symptoms: A Diagnostic Conundrum
Granulomatous and Inflammatory Conditions
Granulomas are tiny clusters of immune cells that form when the body walls off something it cannot easily destroy. In the spleen, sarcoidosis and tuberculosis are two of the more recognizable causes. Both diseases usually produce a diffuse scattering of tiny nodules throughout the organ, but they can occasionally coalesce into a single large mass that mimics a tumor.1MDPI Diagnostics / Europe PMC. The Spectrum of Solitary Benign Splenic Lesions-Imaging Clues for a Noninvasive Diagnosis Rarer infections like melioidosis, caused by a soil bacterium found in tropical regions, can also produce chronic splenic granulomas that require prolonged intravenous antibiotics.16PubMed Central. Splenic granuloma: Melioidosis or Tuberculosis?
Inflammatory bowel disease, particularly Crohn disease, occasionally affects the spleen. Multiple splenic lesions appearing as the first sign of Crohn disease are rare, but cases have been reported even in adolescents. These lesions probably reflect the same misdirected immune activity that drives intestinal inflammation.17American Academy of Pediatrics (Pediatrics). Multiple Splenic Lesions as the First Manifestation of Crohn Disease in a 13-Year-Old Boy When splenic lesions appear in a young patient without an obvious infectious cause, inflammatory bowel disease belongs on the differential list.
Lymphoma and Other Cancers
The spleen is part of the lymphatic system, so it is naturally vulnerable to lymphoma. Primary splenic lymphoma, where the cancer starts in the spleen rather than spreading there from elsewhere, is dominated by non-Hodgkin types. In one surgical series of 17 cases, 16 were non-Hodgkin lymphoma, with diffuse large B-cell lymphoma being the single most common subtype, followed by splenic marginal zone lymphoma.18PubMed Central. Imaging Findings of Primary Splenic Lymphoma: A Review of 17 Cases in Which Diagnosis Was Made at Splenectomy Symptoms are often vague: an enlarged spleen, fatigue, weight loss, or abdominal fullness. The imaging appearance of splenic lymphoma can range from a single mass to diffuse enlargement with no distinct lesion, which is one reason diagnosis is sometimes delayed.
Cancers from other organs can also spread to the spleen, though this is uncommon compared to metastases landing in the liver or lungs. Melanoma, breast cancer, and lung cancer are the solid tumors most likely to send metastases to the spleen.19PubMed Central. Primary tumors of the spleen In autopsy studies, splenic metastases show up in roughly 2% to 7% of cancer patients, but isolated metastases to the spleen without widespread disease elsewhere are genuinely rare, with fewer than 100 such cases reported across all tumor types, most originating from ovarian or colorectal cancer.20Journal of Thoracic Oncology. Isolated Splenic Metastasis from Large Cell Lung Carcinoma
Trauma and Its Aftermath
The spleen is one of the organs most frequently injured in blunt abdominal trauma, the kind that happens in car crashes, falls, and contact sports. Traumatic lesions include lacerations, where the tissue is torn; parenchymal hematomas, where bleeding is contained within the spleen’s substance under an intact capsule; and subcapsular hematomas, where blood collects between the capsule and the underlying tissue in a lens-shaped pocket.21PubMed Central. Imaging findings of splenic emergencies: a pictorial review – Section: Splenic injury22PubMed Central. Computed tomography of blunt spleen injury: a pictorial review Subcapsular hematomas deserve special attention because they can lead to delayed splenic rupture days or even weeks after the initial injury, when the blood eventually breaks through the capsule.
Trauma to the spleen can also leave behind pseudocysts and scarring that show up on imaging years later. And in cases where the spleen is badly damaged or removed, fragments of splenic tissue can implant elsewhere in the abdomen, a condition called splenosis.
Splenosis and Other Look-Alikes
Splenosis deserves its own discussion because it is one of the most common mimics of metastatic cancer on abdominal imaging. After a traumatic splenic rupture or surgical spleen removal, small fragments of viable splenic tissue can seed themselves throughout the abdominal cavity and grow into nodules. These implants often remain silent for decades and are discovered incidentally on scans done for other reasons. The problem is that on CT or MRI, splenosis nodules can look strikingly like metastatic cancer, lymphoma, or peritoneal spread of a tumor, prompting extensive and sometimes invasive workups that turn out to be unnecessary.23PubMed Central. Intra-abdominal Splenosis Mimicking Metastatic Disease During Evaluation for Bacteremic Sepsis A nuclear medicine scan using heat-damaged red blood cells, which are selectively taken up by splenic tissue, is the standard way to confirm splenosis without surgery. If you have a history of spleen injury or removal and are told about suspicious abdominal nodules, mentioning that history to your doctor can prevent a lot of unnecessary worry.
How Splenic Lesions Are Found and Evaluated
Most splenic lesions are discovered incidentally during imaging performed for another reason. Once a lesion is spotted, the challenge is figuring out whether it is harmless or needs further action. Contrast-enhanced imaging is the starting point. A meta-analysis comparing different imaging methods for detecting splenic malignancies found that PET scans had the highest overall accuracy, with a sensitivity of about 93% and specificity around 83%. Contrast-enhanced ultrasound, CT, and MRI all performed well too, with no statistically significant differences among them, though all four outperformed non-contrast methods.24PubMed Central. Diagnostic performance of different imaging modalities for splenic malignancies: A comparative meta-analysis
When imaging alone cannot determine whether a lesion is benign or malignant, a needle biopsy of the spleen may be recommended. People are sometimes alarmed by this because the spleen is a blood-rich organ and the idea of poking a needle into it sounds risky. The actual complication rate is moderate but manageable. In one study, image-guided core needle biopsy had a diagnostic accuracy of about 95%, with minor complications in roughly 7% of cases and a single major complication in about 1%.25PubMed. Safety and Accuracy of Percutaneous Image-Guided Core Biopsy of the Spleen A multicenter study looking specifically at larger needle sizes found that bleeding occurred in about 8% of procedures overall, and only about 2% required treatment. No procedure-related deaths were recorded.26PubMed. A Multicenter Study of Needle Size and Safety for Splenic Biopsy For suspected lymphoma presenting as a diffusely enlarged spleen without a distinct mass, biopsy can still achieve a sensitivity around 88% and accuracy of 92%.27PubMed Central. Percutaneous image-guided biopsy for non-mass-forming isolated splenomegaly and suspected malignant lymphoma
When and How Splenic Lesions Are Treated
Treatment depends entirely on what the lesion turns out to be. Many benign lesions, like small hemangiomas and stable cysts, need nothing beyond periodic imaging to confirm they are not growing. Infectious causes are treated with the appropriate antimicrobial therapy: antibiotics for bacterial abscesses, antifungals for Candida or Aspergillus, and antiparasitic drugs like albendazole for hydatid cysts. Splenic infarcts from identifiable causes like atrial fibrillation or blood disorders are managed by treating the underlying condition and preventing further clots.
Surgery becomes necessary when malignancy is confirmed or cannot be ruled out. For cancerous lesions, total splenectomy is the standard approach. For benign lesions that are causing symptoms or are large enough to pose a rupture risk, partial splenectomy may be an option, preserving as much functional splenic tissue as possible.28PubMed. Diagnosis and treatment of focal splenic lesions In children, where preserving the spleen matters even more because of its role in fighting infections during development, surgical indications are weighed carefully. One pediatric center reported that surgery was reserved for cases with clinical symptoms, lesions larger than 5 centimeters, or situations where malignancy needed to be excluded. Some children with splenic hemangiomas were instead treated with interventional embolization, cutting off blood flow to the mass without removing the spleen.29PubMed Central. Surgical treatment of benign splenic lesions in pediatric patients: a case series of 30 cases from a single center
Splenic Lesions in Children
The differential diagnosis for splenic lesions in children overlaps with adults but has a few distinctive features. Infections and inflammatory conditions account for most pediatric splenic lesions rather than malignancy. As noted earlier, multifocal splenic lesions in a child can occasionally be the first sign of Crohn disease, even before any gastrointestinal symptoms appear.17American Academy of Pediatrics (Pediatrics). Multiple Splenic Lesions as the First Manifestation of Crohn Disease in a 13-Year-Old Boy Fungal microabscesses are a particular concern in children undergoing chemotherapy, where a weakened immune system allows ordinarily harmless fungi to invade.12PubMed. Splenic microabscesses in the immune-compromised patient
Because spleen removal in children raises the lifelong risk of serious bacterial infections, pediatric specialists tend to be more conservative about surgery. For benign conditions like SANT, the trend is moving toward confirming the diagnosis with a needle biopsy and then monitoring rather than operating, though that strategy still needs validation in larger studies.6PubMed Central. Imaging and pathological features of pediatric sclerosing angiomatoid nodular transformation of the spleen: a case series and hypothesis-generating perspective on non-operative management The principle is straightforward: remove the spleen only when you have to, and explore every reasonable alternative first.