Atypical Dermatological Manifestations as Initial Signs of Acute Leukemia in Pediatrics: Incidence Analysis and Diagnostic Delays

Background

Acute leukemia is the most common malignancy in pediatrics, accounting for approximately 30% of all childhood cancer diagnoses. While classic presentations typically feature fever, hepatosplenomegaly, and leukocytosis, atypical extramedullary manifestations like leukemia cutis frequently mimic infectious or inflammatory dermatoses. In the absence of circulating peripheral blasts, these cutaneous signs cause severe diagnostic ambiguity and critical therapeutic delays.

Hypothesis Pediatric acute leukemias presenting with primary dermatological infiltrates experience a markedly longer diagnostic delay and higher rates of initial misclassification compared to those presenting with classic hematologic symptoms, underscoring the necessity of early tissue histopathological evaluation.

Methods

A retrospective synthesis and comparative analysis of clinical data from recent literature (2015–2025) were conducted on pediatric patients presenting with acute leukemia manifesting primarily via cutaneous infiltrates. Evaluated variables included time-to-diagnosis, initial peripheral blood smear accuracy, frequency of misleading initial diagnoses, and subsequent cytogenetic abnormalities.

Results

Analysis of atypical presentations reveals that up to 25–30% of congenital and infant leukemia cases exhibit cutaneous infiltration as the primary sign. Initial peripheral blood screening and immunophenotyping frequently yielded false-negative results in over 50% of these cases due to the absence of circulating leukemic blasts at onset. The average diagnostic delay for patients presenting primarily with dermatological features ranged from 10 to 21 days longer than for patients with classical systemic presentations. Diagnostic accuracy was achieved primarily through secondary skin biopsies with immunohistochemistry or bone marrow evaluation prompted by persistent cytopenias or hyperinflammatory complications like secondary hemophagocytic lymphohistiocytosis (HLH).

Conclusions

Atypical dermatological manifestations in pediatrics serve as a critical warning sign of underlying acute leukemia that can easily bypass standard peripheral hematologic screening. Implementing early skin biopsy protocols in pediatrics patients with unexplained purpuric or nodular rashes is imperative to mitigate therapeutic delays, bypass initial misdiagnoses, and improve long-term clinical outcomes in pediatric oncology.