Prefibrotic Primary Myelofibrosis

**Semantic type:** Neoplastic Process

**Definition:** Primary myelofibrosis characterized by bone marrow hypercellularity and the presence of atypical megakaryocytes. There is no increase in the percentage of myeloblasts and no significant increase in reticulin or collagen fibrosis in the bone marrow.

**Synonyms:** - Early/Prefibrotic Primary Myelofibrosis - Early/Prefibrotic Stage PMF - Early/Prefibrotic Stage Primary Myelofibrosis - Pre-PMF - Prefibrotic/Early Primary Myelofibrosis - Primary Myelofibrosis, Prefibrotic Stage - Primary Myelofibrosis, Prefibrotic/Early Stage