Pleural and Thoracic Air-Leak Complications After Hematopoietic Cell Transplantation: Diagnosis and Procedural Management

Pleural and thoracic air-leak complications after hematopoietic cell transplantation (HCT) are clinically important but underrepresented in broad post-transplant pulmonary reviews. Direct evidence is concentrated in adult allogeneic HCT. In a cohort of 618 adults, clinically significant pleural effusion had a 1-year cumulative incidence of 9.9% (95% confidence interval, 7.7–12.5%). A separate computed tomography-based cohort of 178 first allogeneic HCT recipients reported a day-100 cumulative incidence of 41.0%; these estimates are not directly comparable because the populations, ascertainment methods, endpoints, and follow-up differed. In 50 HCT recipients undergoing thoracentesis, a specific diagnosis was established in 26%, with 5 pneumothoraces and 0 hemothoraces. Thoracic air-leak syndrome is uncommon but carries poor outcomes in reported adult and pediatric series. This focused narrative review distinguishes direct HCT evidence from data extrapolated from hematologic malignancy, general pleural practice, critical care, interventional radiology, and cellular therapy. We organize evaluation by urgency, transplant phase, and radiographic pattern; define chronic graft-versus-host disease serositis as a diagnosis of exclusion; summarize chylothorax and pleural infection management; and provide procedure-specific safety considerations for thoracentesis, small-bore drainage, indwelling pleural catheters, intrapleural enzyme therapy, and pleural biopsy. No prospective HCT-specific trials validate these procedural pathways. Clinicians should therefore use ultrasound or image guidance; apply procedure-specific rather than uniform hemostatic thresholds; and integrate infection risk, platelet trajectory, anticoagulant exposure, oxygenation, operator setting, and expected benefit. The two clinical frameworks presented are proposed and non-validated.