Angiosarcoma of the spleen
An angiosarcoma of the spleen is a rare malignant splenic neoplasm. The term is usually given to describe a primary angiosarcoma of the spleen although angiosarcoma elsewhere can also rarely metastasise to the spleen. Despite its absolute rarity, a splenic angiosarcoma is considered the most common primary splenic malignancy 2.
The general consensus is that there is no recognised gender predilection (occurs almost equally in females and males) 1. Occasional publications, however, suggest a slight male predilection 4. The peak incidence is thought to be around the 6th decade.
Clinical symptomatology can be highly variable, often posing difficult diagnostic problems.
Macroscopic examination often shows splenomegaly with cut sections revealing discrete lesions in a majority of cases. These can range from well-circumscribed firm nodules to poorly delineated foci of necrosis and haemorrhage associated with cystic spaces. Microscopically, the tumours are often heterogenous. The lesions typically demonstrate focal vasoformative component lined by atypical endothelial cells. Solid sarcomatous, papillary, and epithelioid growth patterns can be observed.
Unlike with primary hepatic angiosarcoma, there is no known association between splenic angiosarcoma and occupational exposure to chemicals, such as vinyl chloride or arsenic, or prior injection with the contrast agent thorium dioxide 4.
Reported sonographic features are nonspecific and include splenomegaly with cystic and solid masses with mixed echogenicity 4.
CT may show solitary or multiple nodular masses of heterogeneous low attenuation in an enlarged spleen. There is generally irregular and poorly defined contours, is often detected in a globally enlarged spleen 16.
Occasional large subcapsular intrasplenic or perisplenic extracapsular blood collections (haemoperitoneum) may be present.
Some of these masses may show peripheral enhancement with the margins of the lesions are often irregular or poorly marginated.
- pre-contrast CT: the tumours may appear hyperattenuating due to components of acute haemorrhage.
- dynamic contrast-enhanced CT scans: the lesions may exhibit substantial peripheral contrast enhancement similar to that of hepatic haemangiomas 4.
On occasion, CT scans may show a moderate splenomegaly with micronodular involvement of the organ 16.
Reported MRI features include:
T1 and T2:
- nodular hypointense (relative to the normal adjacent splenic parenchyma) masses on both T1- and T2-weighted images
- large masses with increased signal intensity on both T1- and T2-weighted images that are likely related to areas of subacute haemorrhage, as well as tumour necrosis
- areas of decreased signal intensity within the tumour, owing to chronic haemorrhage with haemosiderin deposition
- C+ (Gd): usually shows intense and multinodular (heterogenous 15) enhancement with focal areas of non-enhancement, likely representing intratumoral haemorrhage and necrosis
Treatment and prognosis
It is an extremely aggressive fatal neoplasm at is almost universally fatal (median survival at approximately 24-36 months at the time of initial writing11) despite treatment 3,5. Distant metastases occur most frequently in the liver (approximately 70% of cases), lung, pleural lymph nodes, bone, and brain. Prompt splenectomy prior to splenic rupture may improve survival 5.
- spontaneous splenic rupture 2,4: can occur in up to 30% of cases 4
History and etymology
It was first described in 1879 by T Langhans 1.
General imaging differential considerations include vascular splenic lesions such as:
- splenic haemangioma
- Littoral cell angioma of spleen
- lymphangioma of spleen
- haemangiopericytoma of spleen
- 1. Chung YF, Busmanis I, Hong GS et-al. Splenic angiosarcoma--an unusual cause of bleeding gastrointestinal tract. Singapore Med J. 1999;40 (2): 106-8. - Pubmed citation
- 2. Vrachliotis TG, Bennett WF, Vaswani KK et-al. Primary angiosarcoma of the spleen--CT, MR, and sonographic characteristics: report of two cases. Abdom Imaging. 25 (3): 283-5. Abdom Imaging (link) - Pubmed citation
- 3. Neuhauser TS, Derringer GA, Thompson LD et-al. Splenic angiosarcoma: a clinicopathologic and immunophenotypic study of 28 cases. Mod. Pathol. 2000;13 (9): 978-87. doi:10.1038/modpathol.3880178 - Pubmed citation
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- 8. Falk S, Krishnan J, Meis JM. Primary angiosarcoma of the spleen. A clinicopathologic study of 40 cases. Am. J. Surg. Pathol. 1993;17 (10): 959-70. - Pubmed citation
- 10. Thompson WM, Levy AD, Aguilera NS et-al. Angiosarcoma of the spleen: imaging characteristics in 12 patients. Radiology. 2005;235 (1): 106-15. doi:10.1148/radiol.2351040308 - Pubmed citation
- 11. Hsu JT, Chen HM, Lin CY et-al. Primary angiosarcoma of the spleen. J Surg Oncol. 2005;92 (4): 312-6. doi:10.1002/jso.20419 - Pubmed citation
- 12. Ha HK, Kim HH, Kim BK et-al. Primary angiosarcoma of the spleen. CT and MR imaging. Acta Radiol. 1994;35 (5): 455-8. - Pubmed citation
- 13. Kaneko K, Onitsuka H, Murakami J et-al. MRI of primary spleen angiosarcoma with iron accumulation. J Comput Assist Tomogr. 16 (2): 298-300. - Pubmed citation
- 14. Kinoshita T, Ishii K, Yajima Y et-al. Splenic hemangiosarcoma with massive calcification. Abdom Imaging. 24 (2): 185-7. Abdom Imaging (link) - Pubmed citation
- 15. Imaoka I, Sugimura K, Furukawa M et-al. CT and MR findings of splenic angiosarcoma. Radiat Med. 17 (1): 67-70. - Pubmed citation
- 16. Ferrozzi F, Bova D, Draghi F et-al. CT findings in primary vascular tumors of the spleen. AJR Am J Roentgenol. 1996;166 (5): 1097-101. AJR Am J Roentgenol (citation) - Pubmed citation
- normal appearance of the spleen
- pseudolesion of the spleen: inhomogeneous splenic enhancement
splenic lesions and anomalies
- congenital anomalies
- mass lesions
- infiltrative processes
- incidental splenic lesion (approach)