Clinical features:
(1) abdominal pain
(2) spontaneous splenic rupture with intra-peritoneal hemorrhage
(3) splenomegaly
(4) weight loss
(5) anemia-related symptoms (fatigue, weakness)
(6) FUO (fever of unknown origin)
(7) gastrointestinal bleeding
Metastases are common and may involve:
(1) bone
(2) liver
(3) GI tract
(4) lung
(5) lymph nodes
(6) soft tissue
Laboratory findings:
(1) anemia
(2) thrombocytopenia
Imaging studies may show:
(1) heterogeneous echotexture
(2) cystic areas secondary to hemorrhage and necrosis
(3) areas of calcification
(4) areas of hemorrhage
(5) hypervascular areas
(6) siderotic nodules
Pathologic features may include:
(1) one or more splenic nodules with areas of necrosis, hemorrhage and pseudocysts
(2) nodules composed of spindle cell with irregular vascular spaces lined by atypical endothelial cells
(3) extramedullary hematopoiesis may be present
(4) intracytoplasmic hyaline globules may be present
Immunohistochemical staining may be positive for:
(1) vimentin
(2) vascular markers: CD31, CD34, VEGFR3, Factor VIII related antigen
(3) histiocyte markers: CD68, lysozyme
