19 May 2010 – Case of the Week #179
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Case of the Week #179
A 62 year old woman presented with sudden epigastric pain. Her medical history included hypertension, nicotine abuse, pneumonia one year prior to admission and Psoriasis vulgaris treated with methotrexate until 2006. She had no history of recent trauma.
Physical examination revealed a tense abdomen, diffuse abdominal pain and a blood pressure of 91/63. Laboratory tests showed decreased haemoglobin of 88 g/L, but her white blood cell and platelet counts were within normal limits.
Ultrasound and CT scan (below) revealed rupture of a normally sized spleen. CT scan demonstrated perisplenic hematoma and blood in the abdominal cavity. At open splenectomy, approximately 3 liters of hematoma was removed.
The resected spleen was normal weight and size (80 grams, 8x7x1.5 cm). The cut surface had multiple circumscribed, cystic, spongy, blood filled nodules ranging from 0.2 to 1.3 cm. Several foci were close or adjacent to the organ capsule.
CD34 CD68 CD21 CD8
What is your diagnosis?
Littoral cell angioma of the spleen
Microscopy showed tall lining cells with vesicular nuclei and small nucleoli, in addition to several exfoliated cells in the vascular spaces, and haemophagocytosis. The cystic lesions correspond to a network of anastomosing, complex vascular spaces of varying diameter. Papillary projections and cyst-like spaces were also demonstrated. No atypia was present. Immunohistochemical analysis showed positive staining of the lining cells with CD21, CD68 and CD31 (not shown), but negative staining for CD34 and CD8.
Littoral cell angioma is a rare tumor of the spleen, first described in 1991 (AJSP 1991;15:1023). The tumor cells appear to derive from littoral cells, the specialized endothelial cells that line the splenic sinuses. The littoral cells lie on a fenestrated basement membrane and are separated by tight junctional complexes. They have an endothelial and histiocytic immunophenotype, and are negative for CD34, in contrast to conventional endothelial cells (Arch Pathol Lab Med 2004;128:1183).
The differential diagnosis of splenic vascular lesions includes:
Angiosarcoma: vascular channels lined by atypical, hyperchromatic cells with intracytoplasmic hyaline globules; frequent hemorrhage, necrosis, hemosiderin, extramedullary hematopoiesis; CD31+, CD34+, CD68+
Hamartoma: disorganized red pulp elements, no angiomatoid nodular pattern, no follicles, CD8+, CD31+, CD21-, CD68-
Hemangioma, focal: usually 2 cm or less, very common, CD31+, CD34+, CD8-, CD21-, CD68-
Hemangioma, diffuse: CD34+, CD68+
Splenectomy is usually curative. Littoral cell angioma typically has a benign clinical course, although exceptional cases with malignant behavior have been reported (Am J Surg Pathol 2006;30:1036). In this case, the patient has remained well at 10 months of follow-up.
Nat Pernick, M.D., President,
and Kara Hamilton, M.S., Associate Medical Editor
30100 Telegraph Road, Suite 408
Bingham Farms, Michigan (USA) 48025
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