The lung parenchyma shows alveolar septal thickening, type II pneumocyte hyperplasia, and focal subpleural fibrosis with a sparse chronic inflammatory infiltrate. The bronchopleural fistula communication features a lumen filled with extensive acellular necrotic debris and dense fibrinopurulent exudate. The underlying tract wall consists of highly vascular granulation tissue and organized collagenous fibrosis densely infiltrated by a mixed population of neutrophils, lymphocytes, histiocytes, and plasma cells. The adjacent lymph node shows follicular hyperplasia and dilated medullary sinuses. No granulomas, viral inclusions, or cytological features of malignancy are identified.
Large bronchopleural fistula.
Soft tissue fragments collectively measured 9.5x8.5x0.6 cm, largest 6x4x0.6 cm, totally embedded.
Bronchopleural fistula, excision: