# Three-Way Translocation t(12;15;17) (p13;q24;q21) Found in Acute Promyelocytic Leukemia with Basophilic Differentiation

## TL;DR

This paper reports a rare case of acute promyelocytic leukemia with a three-way chromosome translocation and basophilic differentiation that responded well to standard treatment.

## Contribution

First report of a three-way translocation t(12;15;17) in basophilic acute promyelocytic leukemia.

## Key findings

- The patient had a three-way translocation t(12;15;17) (p13;q24;q21) instead of the typical t(15;17).
- The patient showed basophilic differentiation, which is rare and often associated with poor outcomes.
- The patient achieved complete remission with standard ATRA and ATO treatment.

## Abstract

Acute promyelocytic leukemia is a rare form of acute myeloid leukemia in which immature promyelocytes abnormally proliferate in the bone marrow. In most cases, the disease is characterised by the translocation t(15;17) (q24;q21), which causes the formation of PML::RARA, an oncogenic fusion protein responsible for blocking myeloid differentiation and survival advantage. Here, we present a case of acute promyelocytic leukemia with two unusual features: basophilic differentiation and a three-way translocation involving chromosomes 12, 15 and 17. In the few cases reported, basophilic differentiation was associated with a poor prognosis. In contrast, our patient responded promptly to the standard treatment with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) and obtained complete remission. To our knowledge, this is the first report of basophilic acute promyelocytic leukemia with the three-way translocation t(12;17;15) (p13; q24;q21).