# Case report: A case of mast cell leukemia treated with avapritinib: from diagnostic challenge to transplantation

## TL;DR

This paper presents a case of mast cell leukemia treated with avapritinib and allogeneic stem cell transplantation, emphasizing diagnostic and treatment challenges.

## Contribution

The novelty lies in the detailed clinical case report and review of emerging therapies for mast cell leukemia.

## Key findings

- Avapritinib and allogeneic stem cell transplantation were used in treating a 66-year-old MCL patient.
- The case highlights the diagnostic complexity and treatment challenges of mast cell leukemia.
- Improved clinical awareness and multidisciplinary approaches are emphasized for better patient outcomes.

## Abstract

Systemic mastocytosis (SM) is a rare hematological neoplasm characterized by the proliferation and accumulation of clonal mast cells (MCs) in the skin, bone marrow, and other extracutaneous organs. Mast cell leukemia (MCL) is the rarest and more aggressive subtype of SM, with very poor prognosis and abysmal survival. Treatment strategies are poorly defined and non-standardized, ranging from symptomatic management to KIT-targeted tyrosine kinase inhibitors and, in selected cases, allogeneic stem cell transplantation, currently the only potentially curative chance for MCL patients. Here, we report a case of a 66-year-old woman affected by MCL, highlighting clinical features, diagnostic challenges and complexity, and our treatment choices. Furthermore, we review current literature data and emerging therapeutic approaches, emphasizing the importance of greater clinical awareness and comprehensive multidisciplinary approach to correctly diagnose and treat this condition in order to improve patient outcomes in this challenging disease.