Diagnosis of GLILD in a Pediatric Patient Via Transbronchial Lung Cryobiopsy: A Case Report and Systematic Review of the Literature

Background Granulomatous–lymphocytic interstitial lung disease (GLILD) is a rare pulmonary complication associated with primary and secondary immunodeficiencies. It is characterized by lymphocytic and granulomatous infiltration and poses diagnostic challenges due to overlapping features with infections and autoimmune conditions. Case Presentation We report an 8‐year‐old child with monogenic lupus and combined T‐ and B‐cell immunodeficiency who presented with recurrent respiratory infections, cytopenias, hepatosplenomegaly, and diffuse pulmonary infiltrates. Imaging revealed persistent ground‐glass opacities and consolidations. To establish a definitive diagnosis, transbronchial lung cryobiopsy (TBLC) was performed under general anesthesia. Three adequate specimens were obtained from the right lower lobe without complications. A systematic literature review was also conducted using PubMed and Scopus to evaluate reported pediatric GLILD cases and biopsy approaches. Results Histopathology confirmed non‐caseating granulomatous inflammation with lymphocytic infiltration, while special stains excluded infections. A diagnosis of GLILD was established, and rituximab therapy was planned in addition to ongoing MMF and immunoglobulin replacement. The literature review revealed limited pediatric cases, with surgical lung biopsy historically preferred. Conclusion This case highlights the feasibility and safety of TBLC for diagnosing GLILD in immunocompromised children. PROSPERO ID: 1142148.