Myeloid Sarcoma with Skin and Spinal Lesions and KRAS Gene Mutation, Complicated by Secondary Hemophagocytic Syndrome: A Case Report and Literature Review

Myeloid sarcoma (MS) is a rare hematologic tumor of immature myeloid cells with lesions located outside the bone marrow. The disease can develop de novo as extramedullary myeloid tumor, be a manifestation of acute myeloid leukemia (AML) or be diagnosed as an AML relapse after previously achieved remission. MS occurs in all age groups, although more commonly in elderly people. Diagnosis is based on immunomorphological and molecular genetic analyses of the tumor tissue. The most effective treatment regimens in MS are those used for AML therapy with subsequent allogeneic hematopoietic stem cell transplantation provided that the first complete remission was achieved. In addition to that, radiotherapy as well as biological and targeted drugs are administered. Nevertheless, the prognosis of the disease remains generally unfavorable. The present paper reports a clinical case of MS with KRAS mutation, tumor skin and Th5–Th6 lesions, spinal cord compression, and developing flaccid paraplegia. The patient received chemotherapies of varying intensity as well as hypomethylating agents combined with venetoclax and the targeted drug trametinib. The course of the disease was complicated by secondary hemophagocytic syndrome (SHS). The present case report demonstrates the challenges of both diagnosis and treatment of this rare and poor-prognosis extramedullary myeloid tumor complicated by SHS.