Abstract

Myeloid sarcoma (MS) is a tumoral mass which is derived from immature myeloid precursor cells. A 28 year old man without a medical history was diagnosed as isolated MS of testis and orchiectomy was performed. After a watch and wait approach, one year later relapse occured in the other testis without bone marrow involvement. Orchiectomy to the other testis was repeated. One year later, the patient presented to our hospital with masses at inguinal and right popliteal regions. Body 18F-FDG PET/CT showed increased FDG uptake in lymph nodes of aortocaval, paraaortic, paracaval, bilateral common iliac, right external iliac, bilateral inguinal regions with a diameter of maximum 3.7 cm and a SUVmax of 11.9; and also a heterogenous FDG uptake was observed in the muscles of posterior leg region. We performed bone marrow biopsy and aspiration resulting in no pathological infiltration. The patient was treated with induction treatment of AML, followed by consolidation with one cycle of high dose ARA-C. After the first cycle of high dose ARA-C, leucocytosis developed. Peripheral smear revealed blastoid cells. Response could not be achieved with salvage therapies. In conclusion, MS might show a complicated disease course and patients with isolated MS should be treated with systemic chemotherapy at first diagnosis.