Iatrogenic Aerogenous Tumor Spread after CT-guided Lung Biopsy.

Tumor spread through airspaces (STAS) is a recognized pattern of aerogenous invasion; however, the potential role of biopsy-related hemorrhage in contributing to STAS-like dissemination remains uncertain. The authors present a case in which new ground-glass opacities appeared 20 months after CT-guided biopsy and were spatially aligned with the immediate postbiopsy alveolar hemorrhage tract. Biopsy of these lesions revealed minimally invasive adenocarcinoma with an epidermal growth factor receptor exon 19 deletion identical to that of the index tumor. This radiologic, pathologic, and molecular concordance supports iatrogenic aerogenous spread rather than de novo multifocal disease. This case highlights the importance of hemorrhage-aware biopsy planning, real-time documentation of hemorrhage pathways, and early postbiopsy CT surveillance when hemorrhage extends along bronchovascular bundles. Keywords: Lung Adenocarcinoma, Ground-Glass Opacity, Spread Through Air Spaces, Iatrogenic Complication, CT-Guided Biopsy, Tumor Seeding, Lung Hemorrhage Supplemental material is available for this article. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license.