A Rare Case of Extramedullary Blastic Transformation(Myeloid Sarcoma-Megakaryoblastic) in a Patient with Primary Myelofibrosis

ABSTRACT

Introduction: Myeloid sarcoma is a tumour composed of myeloidblasts, with or without maturation ocurring at extramedullary sites.Myeloid sarcoma with megakaryoblastic transformation in chronicmyelofibrosis is very rare. Only a few cases have been reported tilldate.Aims &Objectives: A 54 year old male, known case of primarymyelofibrosis since 5 years, diagnosed and treated in a tertiary hospital was referred to our hospital. He was on Hydroxurea andsymptomatic treatment. However due to absence of follow up andfurther treatment as a result of Covid 19 pandemic, he presented witha flare up of the disease, in the form of generalised significant lymphadenopathy (cervical, mediastinal, abdominopelvic) along withhepatosplenomegaly.Materials &Methods: Peripheral smear and bone marrow weresuggestive of a myeloproliferative neoplasm. Bone marrow showedMF grade 2 fibrosis with atypical megakaryocytes/blasts. Biospy fromcervical and abdominal lymph nodes were done.Result: Histology and IHC studies revealed myeloid sarcoma (AMLM7 type).Conclusions: Myeloid sarcomas are an infrequent neoplasms withonly around 2000 case reports in Pubmed. Myeloid sarcoma withmegakaryoblastic transformation in chronic myelofibrosis is veryrare, with extremely poor prognosis. The incidence of myeloid sarcoma occurring at multiple anatomical sites is less than 10%. Sinceonly a few comprehensive studies have been published, treatment alsoposes many difficulties. Hence reporting of cases of myeloid sarcomais significant.