Imaging Pearls ❯ Spleen ❯ Benign Tumors
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- Cystic Lesions of the Spleen
- Congenital cyst
--- Also called epithelial cyst, epidermoid, meesothelial, primary or true cyst.
--- Congenital in origin, and is defined by the presence of an inner epithelial lining.
--- Typically seen as a large, unilocular, fluid density mass with imperceptible walls on CT.
- False cyst
--- False cysts or non-epithelial cysts are thought to result from previous trauma, infarction, or infection of the spleen.
--- It is often difficult to differentiate a true cyst from a false cyst radiologically.
Cyst wall calcification is more common in false cyst (50%). - Cystic Lesions of the Spleen
- Echinoccocal cyst
--- Well-circumscribed, round or ovoid cystic mass on CT. Cyst wall calcification is common.
- Intrasplenic involvement of pancreatic pseudocysts
--- Pancreatic pseudocysts may present as a cystic lesion adjacent to or within the spleen.
--- Associated findings of acute or chronic pancreatitis are usually present.
--- Patients with splenic pseudocysts are prone to splenic rupture with even minor trauma, and should be monitored closely.
- "The definitive diagnosis is established with the histological findings, characterized by the presence of inflammatory cells with areas of necrosis and fibrosis. There are multiple differentials diagnoses: metastasis, lymphoma, splenic infarction, hemangiomas, vascular malformations, lymphangioma, plasmacytoma, reactive lymphoid hyperplasia, abscess and infectious granulomatous processes; therefore suspicion of malignant neoplasm must be considered, being indicated splenectomy to confirm the diagnosis.”
Inflammatory pseudotumor of spleen: a case report.
Ugalde P et al.
Int J Surg Case Rep. 2015;7C:145‐148. - "Radiological tests could orientate but there are not pathognomonic images. Ultrasound can show a hypoechoic splenic mass with or without calcifications.CT can show a low density injury that usually has an attenuated central zone corresponding with fibrosis in the histological findings. Calcifications may be present.”
Inflammatory pseudotumor of spleen: a case report.
Ugalde P et al.
Int J Surg Case Rep. 2015;7C:145‐148. - “Inflammatory pseudotumor of the spleen is a rare benign process with nonspecific CT features. The mass was generally hypodense with delayed enhancement on CT.”
Computed tomographic and clinicopathological features of inflammatory pseudotumor of the spleen.
Lu T, Yang C
J Comput Assist Tomogr. 2015;39(3):409‐413.
- OBJECTIVE. Incidental splenic lesions, often found on CT images of the abdomen, may often be ignored or mischaracterized. Calcified splenic lesions are often presumed to be granulomas; however, understanding the broader differential diagnostic considerations can be useful.
CONCLUSION. Determining the cause of splenic lesions is essential to guide appropriate management; the pattern of calcification together with other imaging and clinical findings can aid with differentiation.
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091 - “In cases in which splenic lesions on CT may not have a characteristic pattern of attenuation or enhancement, the morphologic features and pattern of calcifications can help the differential diagnosis. Using the imaging characteristics of a splenic mass, radiologists can recommend further imaging, surveillance, or more invasive management. Whereas most calci- fied splenic lesions are presumed to be sequelae of prior granulomatous infection, there is a broader differential diagnosis for these lesions. An algorithmic approach to splenic lesions according to their characteristic calcification patterns can therefore narrow the differential diagnosis and help guide management.”
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091 - "The calcifications within hemangiomas can appear as central punctate, curvilinear, or speckled in areas of thrombosis. Multiphase CT of a splenic hemangioma will typically show a hypoattenuating lesion on unenhanced CT, sometimes with early peripheral discontinuous enhancement with uniform delayed enhancement mirroring the blood pool, although this pattern can be obscured because of background parenchyma enhancement. Smaller lesions may show flash-filling enhancement, especially among the capillary subtype, and larger lesions will often show centripetal progression of enhancement with a persistently enhancing central fibrous scar.”
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091 - “Some cysts may have internal septations that enhance with contrast administration. Up to 14% of true epithelial cysts can have thin curvilinear wall calcifications, but calcifications can also be seen within septations. When compared with pseudocysts, which are the primary differential diagnostic consideration for these lesions, true epithelial cysts are more likely to have internal enhancing septations but are less likely to have wall calcifications.”
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091 - "Calcified splenic granulomas are a common incidental finding, most commonly resulting from tuberculosis or histoplasmosis and less commonly from Pneumocystis carinii pneumonia or brucellosis .A risk factor for many of these infections is HIV infection. In all cases, the granulomas are preceded by multiple splenic microabscesses that are hypoattenuating lesions less than 2 cm in diameter. When the microabscesses heal, they may calcify with or without preceding regression. Those that calcify after regression, in cases of histoplasmosis or tuberculosis, may appear as stippled, diffuse calcifications in an otherwise normal spleen.”
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091 - "Cysts typically measure up to 8–16 cm in diameter. On CT, these hydatid cysts are typically well-marginated with internal fluid attenuation and occasional air-fluid levels. At all stages, hydatid cysts may have curvilinear, ringlike peripheral calcifications of the pericyst in up to 20–30% of cases.”
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091 
Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation
Consul N et al.
AJR 2020; 214:1083–1091
- Littoral Cell Splenic Angioma: Facts
- It is a primary vascular tumor arising from the cells lining the splenic red pulp venous sinuses, hence the name littoral cells.
- LCA is a rare splenic vascular tumor discovered either as an incidental finding or patients may present with abdominal pain.
- The gross appearance of the spleen can be slight to moderately enlarged size and weight, with a cross-section showing widened splenic trabeculae and more commonly multifocal than a solitary nodule. - Littoral Cell Splenic Angioma: Facts
The LCA can present as an incidental finding in an asymptomatic patient or as abdominal pain. The physical exam can reveal the presence of splenomegaly in some cases. Other less common clinical features include the presence of anemia, thrombocytopenia, hepatitis, cirrhosis, and portal hypertension. - Littoral Cell Splenic Angioma: Facts
The radiological imaging studies like magnetic resonance imaging (MRI) and computed tomography scan (CT scan) have not proven to be adequate in diagnosing littoral cell angioma, given that it is difficult to differentiate from other splenic neoplasms like angiosarcomas, lymphomas, metastatic tumors on imaging. Owing to the hemosiderin deposits in the tumor cells, hypodense lesions are visible on T1 and T2 weighted MRI images. Sonography evaluation is not helpful because of the variable findings of heterogeneous echotexture and no definite lesions. - Littoral Cell Splenic Angioma: Facts
Currently, splenectomy followed by long term follow up is the recommended treatment for LCA given its malignant potential. Since LCA can be associated with splenomegaly, performing a laparoscopic splenectomy (LS) can be a challenging task. It should only be performed by an experienced surgeon with particular attention to prevent splenic capsule rupture and, consequently, any tumor cell dissemination. - Littoral Cell Splenic Angioma: Facts
The differential diagnosis includes other vascular neoplasms of the spleen, including splenic hemangioma, lymphangioma, hamartoma, angiosarcoma. The LCA can be differentiated from these lesions based on the histopathological and immunophenotyping findings, as detailed above. Imaging studies (MRI, CT scan, ultrasound) have not demonstrated usefulness in differentiating between these. - Littoral Cell Splenic Angioma: Facts
The complications of littoral cell angioma could be secondary to hypersplenism leading to anemia, thrombocytopenia, abdominal pain, and weight loss. Additionally, the patient can develop early postoperative complications of splenectomy performed for treatment of LCA like bleeding, incision site infection, hernia, atelectasis, pulmonary and abdominal sepsis, pancreatitis, pulmonary embolism.
- Purpose: To evaluate whether an incidentally noted splenic mass at abdominal computed tomography (CT) requires further imaging work-up.
Conclusion: In an incidental splenic mass, the likelihood of malignancy is very low (1.0%). Therefore, follow-up of incidental splenic masses may not be indicated.
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 - “Follow-up of splenic masses inci- dentally detected at CT (i.e., in patients with no evidence of previous or newly diagnosed malignancy and no systemic symptoms or localized pain) does not appear to be indicated.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 - “This study included 379 patients, 214 (56.5%) women and 165 (43.5%) men, with a mean age 6 standard deviation of 59.3 years 6 15.3 (range, 21–97 years). There were 145 (38.3%) patients in the malignancy group, 29 (7.6%) patients in the symptomatic group, and 205 (54.1%) patients in the incidental group. The incidence of malignant splenic masses was 49 of 145 (33.8%) in the malignancy group, eight of 29 (27.6%) in the symptomatic group, and two of 205 (1.0%) in the incidental group (P , .0001). The incidental group consisted of new diagnoses of lymphoma in one (50%) patient and metastases from ovarian carcinoma in one (50%) patient. Malignant splenic masses in the incidental group were not indeterminate, because synchronous tumors in other organs were diagnostic of malignancy.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 - “Such incidental findings include masses in the spleen, which have been reported as inciden- tal findings in greater than 14% of autopsies, and most commonly represent hemangiomas, cysts, hamartomas, lymphangiomas, or granulomas.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study
Siewert B et al.
Radiology 2018; 287:156–166
“While the ACR white paper represents a consensus opinion of experts in the field, the follow-up recommendations for splenic masses are based on personal experience of the expert panel, and the panel acknowledged that there were not enough scientific data on which to base this decision. The purpose of our study was, therefore, to evaluate whether an incidentally noted splenic mass at abdominal CT requires further imaging work-up.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 - “The initial “white paper” from the American College of Radiology (ACR) incidental findings committee recommends further evaluation and/or follow-up imaging for all incidental splenic masses greater than 1 cm that do not have clearly benign features at imaging at the time of detection. The majority of such solid splenic nodules and masses are benign, with hemangioma being the most frequent diagnosis. However, CT imaging characteristics of benign and malignant splenic masses often overlap, making definitive differentiation difficult.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166- “In conclusion, in patients with an incidental splenic mass identified at imaging and with the absence of a history of malignancy, fever, weight loss, or pain in the left upper quadrant or epigastrium, such masses are highly likely to be benign regardless of their appear- ance. Additional imaging or follow-up is not warranted, even if the mass does not show the appearance of a simple cyst. Further work-up is only needed if the splenic mass is seen in conjunction with other findings worrisome for malignancy.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 - “In patients with known malignancy or with constitutional symptoms and/or pain localized to the left upper quadrant or epigastrium, although most masses will also be benign, such patients require further assessment.”
The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study Siewert B et al. Radiology 2018; 287:156–166 - SANT-Sclerosing Angiomatoid Nodular Transformation
SANT is a benign nonneoplastic vascular lesion of the spleen. This lesion is thought to arise from a response of the red pulp to underlying stromal inflammation or vascular injury. On pathology, there are dense areas of fibrosis and angiomatoid nodules. SANT usually presents as a solitary lesion. Although patients with SANT are typically asymptomatic, SANT has been associated with pancytopenia and an in- creased erythrocyte sedimentation rate. - SANT-Sclerosing Angiomatoid Nodular Transformation
The imaging findings of a solitary splenic lesion, old hemorrhage, dense fibrosis, and centripetal enhancement should lead to suspicion of SANT.
- “Splenic hemangiomas are the most fre- quently occurring benign tumor of the spleen, with a rate of occurrence in autopsy series of 0.03–14%. Splenic hemangiomas are thought to be congenital in origin, arising from sinusoidal epithelium, and most are the cavernous type. Most hemangiomas are small (reported size range, 0.5–7.0 cm), incidental, and asymptomatic.”
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities Thipphavong S et al. AJR 2014; 203:315–322 - “Lymphangiomas are slow-growing benign tumors that are usually found in the soft tissues of the neck, axilla, mediastinum, retroperitoneum, or extremities. Lymphangiomas can also involve the liver, spleen, kidney, or gastrointestinal tract. Three histologic sub- types are described: simple lymphangiomas, cavernous lymphangiomas, and cystic hygromas. Splenic lymphangiomas can be seen with lymphangiomatosis or systemic cystic angiomatosis (lymphangiomas and hemangi- omas) involving several body parts or organs in the body. Diffuse lymphangiomatosis with splenic involvement is rare, and most cases have been reported in children.”
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities Thipphavong S et al. AJR 2014; 203:315–322 - “On CT, multiple discrete, nonenhancing low-attenuation lesions are present. Lymph-
angiomas are usually subcapsular in location. Curvilinear peripheral mural calcifications can be seen. On MRI, well-circumscribed fluid-signal-intensity lesions are present on T2- weighted images. High signal intensity can be seen on T1-weighted imaging if there has been internal bleeding or if there is a large amount of intracystic proteinaceous material.”
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities Thipphavong S et al. AJR 2014; 203:315–322 - “Splenic hamartomas are tumors composed of a varying mixture of tumor tissue and normal splenic tissue, with reported sizes ranging from 0.3 to 20.0 cm. Hamartomas are solid lesions that may contain a cystic or necrotic component. Splenic hamartomas can be associated with syndromes—namely, tuberous sclerosis and Wiskott-Aldrich-syndrome. Two subtypes of splenic hamartomas can occur: white pulp lesions, which are composed of aberrant lymphoid tissue, and red pulp lesions, which are composed of an aberrant complex of sinuses. Most hamartomas are a mixture of the two subtypes.”
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities Thipphavong S et al. AJR 2014; 203:315–322 - “On unenhanced CT, hamartomas are usually isodense to splenic parenchyma. Depending on size, splenic hamartomas can cause distortion of the splenic con- tour. Sometimes the contour abnormality is the only noticeable feature on unenhanced CT. Calcification, cystic change, and fat can occasionally be seen.”
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities Thipphavong S et al. AJR 2014; 203:315–322
- “Splenic lesions are commonly encountered and are often incidental in nature. Benign splenic vascular neoplasms include hemangioma, hamartoma, lymphangioma, extra-medullary hematopoiesis (EMH), and sclerosing angiomatoid nodular transformation (SANT). Uncommonly encountered entities of the spleen include focal EMH, focal myeloma, angiomyolipoma, and SANT. Primary splenic angiosarcoma is the most common malignant nonhematolymphoid malignancy of the spleen. Lymphoma, myeloma, and metastases are the other malignant entities involving the spleen.”
Nonneoplastic, benign, and malignant splenic diseases: cross-sectional imaging findings and rare disease entities.
Thipphavong S et al.
AJR Am J Roentgenol. 2014 Aug;203(2):315-22 - “Congenital cysts (i.e., epithelial cysts, epidermoid cysts) of the spleen are cysts lined with epithelial cells. These cysts are thought to present as either mesothelial cysts or cysts with squamous metaplasia within preexisting mesothelial cysts, arising from embryonic inclusions of the surface mesothelium in the developing spleen. They usually present in patients without symptoms and are found incidentally on imaging.”
Nonneoplastic, benign, and malignant splenic diseases: cross-sectional imaging findings and rare disease entities.
Thipphavong S et al.
AJR Am J Roentgenol. 2014 Aug;203(2):315-22 - “Splenic hemangiomas are the most frequently occurring benign tumor of the spleen, with a rate of occurrence in autopsy series of 0.03–14% . Splenic hemangiomas are thought to be congenital in origin, arising from sinusoidal epithelium, and most are the cavernous type. Most hemangiomas are small (reported size range, 0.5–7.0 cm) , incidental, and asymptomatic.”
Nonneoplastic, benign, and malignant splenic diseases: cross-sectional imaging findings and rare disease entities.
Thipphavong S et al.
AJR Am J Roentgenol. 2014 Aug;203(2):315-2 - “Splenic hamartomas are tumors composed of a varying mixture of tumor tissue and nor- mal splenic tissue, with reported sizes ranging from 0.3 to 20.0 cm. Hamartomas are solid lesions that may contain a cystic or necrotic component. Splenic hamartomas can be associated with syndromes—namely, tuberous sclerosis and Wiskott-Aldrich- syndrome. Two subtypes of splenic hamarto- mas can occur: white pulp lesions, which are composed of aberrant lymphoid tissue, and red pulp lesions, which are composed of an aberrant complex of sinuses. Most hamartomas are a mixture of the two subtypes.”
Nonneoplastic, benign, and malignant splenic diseases: cross-sectional imaging findings and rare disease entities.
Thipphavong S et al.
AJR Am J Roentgenol. 2014 Aug;203(2):315-22
- Splenic Hemangioma: Facts
- Most common benign splenic tumor
- Can be single or multiple
- May enhance similar to a hepatic hemangioma occassionally
- Multiple lesions may be seen in KTW syndrome - Multiple Splenic Lesions: Differential Dx
- Cysts
- Hemangiomas
- Hamartoma
- Lymphoma
- Metastases
- Abscesses
- Infarcts - Cystic Splenic Lesions: Differential Dx
- Epidermoid cyst
- Hematoma due to trauma
- Post traumatic cyst
- Cystic degeneration of an infarct
- Abscess
- Lymphoma
- Metastases - Splenomegaly: Differential Dx
- Congestion (cirrhosis, CHF, acute sequestration)
- Neoplasm (lymphoma)
- Infection (abscesses)
- Collagen vascular disease (SLE, rheumatoid arthritis
- sarcoidosis - Splenic Hemangioma: Facts
- Most common benign splenic tumor
- Can be single or multiple
- May enhance similar to a hepatic hemangioma occassionally
- Multiple lesions may be seen in KTW syndrome
- Littoral Cell Angioma
- Rare vascular neoplasm of the spleen first described in 1991.
- Commonly an incidental finding, although patients can sometimes present with anemia, thrombocytopenia or splenomegaly.
- Most littoral cell angiomas are benign, but there are case reports of malignant lesions. - Littoral Cell Angioma
- Usually appear as multiple low density nodules varying in size up to 6cm.
- Demonstrate enhancement after IV contrast and in some patients may become isodense to the spleen on delayed images.
- There is nothing specific about the CT appearance. - Sclerosing Angiomatoid Nodular Transformation (SANT) of the Spleen
- Recently recognized
- Rare, 30 reported cases
- Nonneoplastic vascular lesion
- Microscopically, all the reported cases have multiple angiomatoid nodules in a fibrosclerotic stroma
- DDX: splenic hamartoma, inflammatory myofibroblastic tumor, littoral cell angioma, and hemangioendothelioma
- F>>M
- Age 22-74 years - Sclerosing Angiomatoid Nodular Transformation (SANT) of the Spleen
- Most incidental findings in asymptomatic patients
- Some present with abdominal pain or discomfort
- Splenomegaly rare
- Benign course with splenectomy curative - “ While there are several imaging features of SANT which have been described in the literature, it is not routinely possible to make a prospective diagnosis based on the imaging features alone. Moreover, it may not be possible to exclude malignancy based on the imaging features, and needle biopsy or splenectomy may be required in certain cases.”
Sclerosing Angiomatoid Nodular Transformation of the Spleen (SANT) – Multimodality Imaging Appearance of Five Cases with Radiology-Pathology Correlation
Raman SP, Hruban RH, Singhi A, Horton KM, Fishman EK
AJR (submited) - “Finally, as a benign lesion, one would expect that SANT would remain stable in size and appearance over time. While there have been no reports of growth of lesions in the literature, we have seen at least one case where the lesion has grown substantially, eventually necessitating splenectomy. Ultimately, in many cases, there may be no option other than splenic biopsy or splenectomy.”
Sclerosing Angiomatoid Nodular Transformation of the Spleen (SANT) – Multimodality Imaging Appearance of Five Cases with Radiology-Pathology Correlation
Raman SP, Hruban RH, Singhi A, Horton KM, Fishman EK
AJR (submited)
- Sarcoidosis:Abdominal Manifestations
- Up to 59% of patients with sarcoidosis have splenic involvement
- CT findings range from splenomegaly, to solitary nodules to multiple nodules - Sarcoidosis:Abdominal Manifestations
- Liver
- Spleen
- Kidney
- Lymph nodes
- Small Intestine
- Stomach - Sarcoidosis: Facts
- Most common in age range of 30-50
- AfroAmericans affected 3x more frequent then whites
- Pulmonary complications most common cause of death
- Symptoms include fatigue, fever and weight loss - Hamartoma: Facts:
- Rare, occur at any age
- anomalous mixture of splenic elements, congenital
- usually solitary, but can be multiple
- associated with Tuberous Sclerosis - Hamartoma: CT Findings:
- CT appearance
- iso or hypodense on non contrast CT
- slow enhancement after IV contrast
- CT appearance can be similar to hemangioma
- Well-defined - Lymphangioma: Facts
- uncommon splenic tumor
- usually asymptomatic
- cystic type most common in spleen
CT appearance
- usually small and multiple
- cystic (HU 15-35)
- often subcapsular location
- typically do not enhance - Increased Attenuation of the Spleen-Differential Dx:
- Thorotrast
- Sickle cell disease
- Thallasemia
- Hemochromatosis and hemosiderosis
- Treated lymphoma