General Considerations

•histologic types: leiomyosarcoma, FSA, undifferentiated sarcoma, liposarcoma, OSA, CSA, myxosarcoma, rhabdomyosarcoma, and fibrous histiocytoma

•clinical signs: inappetence, abdominal distension, polydipsia, lethargy, vomiting, weight loss, and weakness

•abdominal mass frequently detected with abdominal palpation and survey abdominal radiographs

•treatment: splenectomy

•prognosis is guarded to poor with overall MST 10 weeks

•MST 1 month for dogs with evidence of metastatic disease at surgery

•MST 9 months for dogs with no evidence of metastatic disease at surgery

Splenic Nodular Hyperplasia

General Considerations

•splenic nodular hyperplasia can be classified according to type and proportion of cellular components:

•lymphoid

•hematopoietic

•plasmocytic

•fibrohistiocytic

•mixed

Nodular Fibrohistiocytic Hyperplasia

•nodular fibrohistiocytic hyperplasia may represent a transitional form between nodule and malignant neoplasia (i.e., malignant fibrous histiocytoma or generalized histiocytic sarcoma)

•nodular fibrohistiocytic proliferation in canine spleen characterized by a mixed population of spindle cells in varying proportions with hematopoietic elements, plasma cells, and lymphocytes

•MST 5.0-5.5 months, with 12-month survival rate 48%

•44% of deaths directly attributable to splenic disease

•poor prognostic factors include low lymphoid-to-fibrohistiocytic ratio and high mitotic index