Masking as Myelofibrosis: A Case of Tp53 Mutated Acute Erythroid Leukemia Presenting With Pancytopenia and Bone Pain.

Acute erythroid leukemia is a rare form of acute myeloid leukemia, comprising only 1% of myelogenous leukemia diagnoses. Presentations can vary and given its aggressive nature, prompt investigation and appropriate treatment are needed when suspicions arise. Here, we discuss a case of a 54-year-old male who initially presented with worsening fatigue and dyspnea on exertion and was found to have significant pancytopenia. Bone marrow biopsy initially demonstrated significant fibrosis concerning for primary myelofibrosis, though JAK2 testing was negative. He was started on JAK inhibitor therapy with pacritinib but clinically declined over the next several days with worsening diffuse pain and pancytopenia. A repeat bone marrow biopsy demonstrated acute erythroid leukemia with biallelic Tp53 mutations. He was subsequently started on FLAG-Ida-Ven induction, with complete remission obtained after induction. Transplant work-up was started, and he received a cycle of FLAG-Ida-Ven consolidation. Shortly after, the patient presented to an outside hospital with septic shock, at which point the patient expired. This case illustrates the aggressive nature of the disease, the need for confirmatory testing when diagnosis is suspected and the difficulty in management as the prognosis is poor and requires aggressive treatment that can lead to life-threatening sequelae.