# Diagnosis and management of rare acute erythroid leukemia with hemophagocytic lymphohistiocytosis: a case report

## TL;DR

This case report describes a rare and deadly combination of acute erythroid leukemia and hemophagocytic lymphohistiocytosis, highlighting the challenges in diagnosis and treatment.

## Contribution

The paper presents a detailed clinical case of AEL complicated by HLH, emphasizing the diagnostic process and treatment challenges.

## Key findings

- AEL combined with HLH is rare and difficult to diagnose, requiring comprehensive tests like bone marrow analysis and serum ferritin levels.
- Initial therapies failed to induce remission, but a DAE regimen achieved morphological complete remission.
- Despite treatment, the patient's outcome was poor, underscoring the need for better therapeutic strategies.

## Abstract

Acute erythroid leukemia (AEL) complicated by hemophagocytic lymphohistiocytosis (HLH) is an exceedingly rare hematologic malignancy. Its diagnosis relies on a comprehensive assessment that includes bone marrow cytomorphology, immunophenotyping, cytogenetics, molecular profiling, and serum ferritin levels. Its management poses substantial clinical challenges, and the prognosis is generally guarded.

The patient was admitted due to persistent fatigue for 20 days and recurrent fever. A complete blood count showed pancytopenia: white blood cells (2.99 ×109/L), red blood cells (2×10¹²/L), hemoglobin (70g/L), and platelets (15×109/L). Ferritin levels exceeded 2000µg/L, lactate dehydrogenase (LDH) was elevated to 1414 U/L and triglyceride was normal. The coagulation profile indicated normal fibrinogen levels; however, its degradation product was elevated (7.70μg/mL), along with increased plasma D-dimer (1.48μg/mL). Elevated inflammatory markers included C-reactive protein (33.90mg/L) and procalcitonin (1.400ng/mL). A non-contrast computed tomography (CT) scan revealed bilateral pulmonary inflammatory exudation, atelectasis, and splenomegaly.

Comprehensive bone marrow evaluation confirmed a diagnosis of AEL complicated by secondary HLH. Initial therapy with a decitabine-CAG (aclacinomycin, cytarabine, G-CSF)-venetoclax regimen failed to induce remission. Morphological complete remission was achieved after switching to a DAE (daunorubicin, cytarabine, etoposide) regimen. Despite plans for allogeneic hematopoietic stem cell transplantation, the patient succumbed within 3 months of diagnosis.

This case highlights the diagnostic and therapeutic complexities associated with the co-occurrence of AEL and HLH. Early identification of HLH as a potential complication in AEL is crucial, though outcomes remain dismal, emphasizing an urgent need for novel therapeutic strategies.