# Cutaneous Eruptions as a Consequence of Myeloid Leukemic Infiltration: Differential Diagnosis With a Benign Dermatosis

## TL;DR

This paper discusses a case where skin rashes were caused by a type of blood cancer, highlighting the need for early diagnosis to avoid delays in treatment.

## Contribution

The paper presents a case emphasizing the importance of recognizing leukemia cutis in patients with myeloproliferative neoplasms.

## Key findings

- A patient with essential thrombocythemia developed skin lesions later diagnosed as leukemia cutis.
- Leukemic transformation was identified after initial misdiagnosis as a benign dermatosis.
- Early recognition of skin symptoms can lead to timely treatment in myeloproliferative neoplasm patients.

## Abstract

Leukemia cutis is an uncommon but clinically significant manifestation of hematologic malignancies caused by infiltration of the skin by malignant leukocytes. Its presentation is highly variable and may closely resemble benign inflammatory dermatoses, frequently leading to diagnostic delay.

We report the case of a 76-year-old man with JAK2-positive essential thrombocythemia (ET) who developed persistent, intensely pruritic maculopapular skin lesions initially diagnosed as dermatitis. Despite symptomatic treatment, the lesions progressed and were followed by systemic symptoms. Further investigation revealed acute myeloid leukemia (AML) arising from blastic transformation of ET, with probable cutaneous involvement consistent with leukemia cutis.

This case highlights the importance of maintaining a high index of suspicion when evaluating new or treatment-refractory skin lesions in patients with myeloproliferative neoplasms (MPNs), as early recognition may allow timely diagnosis of leukemic transformation and prompt initiation of appropriate therapy.