# Acute Lymphoblastic Leukemia Characterized by Rare BCR::FGFR1 Translocation: A Case Report With Literature Review

## TL;DR

A rare BCR::FGFR1 translocation in a 60-year-old ALL patient led to aggressive disease and poor prognosis despite treatment, highlighting the need for detailed molecular analysis in ALL diagnosis.

## Contribution

This case report highlights the clinical significance of the rare BCR::FGFR1 translocation in ALL and its impact on treatment outcomes.

## Key findings

- The patient had a rare t(8; 22)(p11; q11) BCR::FGFR1 translocation associated with aggressive ALL.
- Despite achieving cytological remission, MRD positivity persisted, leading to stem cell transplantation.
- The patient died due to graft-versus-host disease and infections post-transplant, underscoring the severity of this translocation.

## Abstract

We present the case of a 60-year-old male patient with a common B-cell acute lymphoblastic leukemia (ALL) who carried the rare t(8; 22)(p11; q11) BCR::FGFR1 chromosomal translocation.

The presence of the t(8; 22)(p11; q11) BCR::FGFR1 translocation, identified by cytogenetics including Fluorescence In Situ Hybridization (FISH) is known for its association with aggressive disease. Given the dismal prognosis, an early search for a stem cell donor was initiated.

The patient was treated according to the German Multicenter ALL (GMALL) Study Group consensus recommendations. The disease was refractory to the first cycle of induction chemotherapy. However, after the second induction, cytological remission was achieved. Nevertheless, minimal residual disease (MRD) positivity persisted (IGH rearrangement detected by PCR) after the first consolidation therapy, giving indication for a stem cell transplantation (SCT).

Thirty days post-transplant, no MRD was detected, and complete chimerism was measured for the months following transplantation. However, the patient died in the context of severe graft-versus-host disease and infectious complications 6 months after the SCT.

This case highlights the importance of detailed molecular analysis in the initial diagnostics of ALL. Identification of specific chromosomal translocations can provide critical insights for risk assessment and aid decision-making in intensify therapeutic approaches.

ClinicalTrials.gov identifier: NCT03011372, NCT04659616