Cytological Findings in Pediatric Thoracic Tumors: A Review of Diagnostic Insights and Pitfalls.

Abstract

Background: Pediatric lung and mediastinal tumors constitute a rare and heterogeneous group of neoplasms, often of embryonal, germ cell, lymphoid, or mesenchymal derivation. Cytology (especially fine-needle aspiration) plays a critical role in the minimally invasive diagnosis of these masses, particularly in children, where surgical biopsy may carry a high risk.

Summary: This review synthesizes the cytomorphologic spectrum of pediatric thoracic tumors, emphasizing distinguishing features, common pitfalls, and the integration of ancillary studies (immunocytochemistry, molecular testing). Special focus is on pleuropulmonary blastoma, inflammatory myofibroblastic tumor, germ cell tumors, lymphomas, Langerhans cell histiocytosis, neurogenic tumors, and small round cell tumors. We propose a structured diagnostic algorithm that incorporates clinical, radiologic, and cytologic data, along with the emerging roles of next-generation sequencing, AI-assisted cytology, and liquid-based methods in pediatric thoracic cytopathology.

Key messages: (1) Accurate cytologic diagnosis in pediatric thoracic masses demands optimal sampling, careful morphologic assessment, and judicious use of ancillary techniques. (2) Improved standardization, multicenter collaborations, and integration of digital/molecular tools hold promise to enhance diagnostic yield and guide therapy in this challenging realm.