Splenic Angiosarcoma with Bone Marrow Involvement Initially Diagnosed as Systemic Mastocytosis: A Case Report.

We describe the case of a 67-year-old female patient presenting with constitutional symptoms and rapid decline. Two bone marrow core biopsies were performed, with spindled cells identified and thought to represent marrow involvement by systemic mastocytosis on the first biopsy. A diagnosis of metastatic vascular malignancy with sarcomatoid features was favored on the second core biopsy. The patient rapidly deteriorated and passed away. The post-mortem examination revealed a splenic angiosarcoma with metastasis to the liver and bone marrow. Splenic angiosarcoma is a rare, aggressive entity, with bone marrow metastasis even more uncommon. This report perceives this as a diagnostic consideration on bone marrow biopsies with spindled cells and explores the diagnostic dilemma and overlapping features of systemic mastocytosis and angiosarcoma.