8 Molecular signature characterization of an aggressive mast cell sarcoma with concurrent systemic mastocytosis in bone marrow, case report and literature review

Introduction/Objective Mast cell sarcoma (MCS) is an extremely rare and aggressive form of mastocytosis often characterized by highly atypical cells showing an infiltrative and destructive growth pattern. It is a challenging diagnosis with poor prognosis. Until now, there is no standard treatment available nor are the molecular alterations well defined. Methods/Case Report Here we report a case of 70 year old male who initially presented to our hospital with high-grade fever, night sweats and unintentional weight loss. Subsequently developed multi-organ failure and distributive shock in the setting of elevated serum ferritin levels concerning for possible hemophagocytic lymphohistiocytosis. CT scan revealed hepatosplenomegaly. Patient’s condition deteriorated significantly, he passed away 2 weeks later. Bone marrow biopsy was done, diagnosed as mast cell sarcoma and an associated systemic mastocytosis. Molecular study by NGS reveals ASXL1, TET2, EZH2 and KIT D816V mutation. Additionally, we did a thorough literature review, identified 43 cases of MCS (including our case) in total and investigated their molecular signature. 14 out of 43 (14/43= 32.6%) patients has KIT mutation. 7/14= 50% cases have KIT D816V mutation. In general systemic mastocytosis 80-90% cases has KIT D816V mutation. Our case which is a combination of MCS and systemic mastocytosis has similar KIT D816V mutation. Results NA Conclusion More cases and molecular studies are needed to further characterize this rare entity for better understanding of disease and to improve prognosis for these patients by availing newer treatment modalities in future.