PULMONARY EPITHELIOID HEMANGIOENDOTHELIOMA IN AN ADOLESCENT: A CLINICAL CASE
Abstract
Pulmonary epithelioid hemangioendothelioma (PEH) is a rare vascular neoplasm of intermediate malignancy characterized by a highly variable clinical course and significant diagnostic challenges. In pediatric practice, the incidence of this condition is extremely low, which often leads to diagnostic errors, particularly in cases with atypical molecular variants. Objective: To demonstrate the clinical, instrumental, and morphological features of pulmonary epithelioid hemangioendothelioma in children and to highlight the challenges of differential diagnosis. Materials and Methods: We present a clinical case of a 14-year-old adolescent with bilateral diffuse lung involvement who underwent a comprehensive diagnostic evaluation, including chest computed tomography, bronchoscopy with biopsy, histological and immunohistochemical analysis, as well as lung function testing. Results: Multiple bilateral pulmonary nodules were identified, while no significant functional impairment was observed. The initial histological findings were consistent with organizing pneumonia. The differential diagnosis included tuberculosis, sarcoidosis, pulmonary alveolar proteinosis, and IgG4-related lung disease. The final diagnosis was established after expert histopathological review, revealing features of PEH with positive expression of endothelial markers (CD31, CD34, ERG) and absence of CAMTA1 and TFE3 expression. This pattern does not correspond to the typical molecular variants observed in the majority of cases and underscores the molecular heterogeneity of the tumor. Conclusion: This case demonstrates that PEH may mimic inflammatory lung diseases and be associated with negative results for key molecular markers (CAMTA1, TFE3). Accurate diagnosis requires a comprehensive approach, including detailed histological and immunohistochemical evaluation. Awareness of this entity in the differential diagnosis of diffuse lung diseases in children may reduce the risk of diagnostic errors and highlights the importance of a multidisciplinary approach involving pediatricians, pulmonologists, oncologists, and pathologists.