Herein, we report an autopsy case of idiopathic pulmonary fibrosis (IPF) in which remarkable honeycomb cyst expansion appeared in the clinical course. Radiological findings initially showed subpleural predominant reticulation that had progressed to usual interstitial pneumonia with honeycomb cysts, along with a restrictive pattern in the pulmonary function tests. The diameter of honeycomb cysts had gradually increased, and some cysts had abruptly expanded at the end stage. Based on pathological findings of autopsy specimens, bronchiectasis, alveolar collapse due to inflammation, and check-valve mechanism caused by a slit-like orifice of the cysts could have contributed to honeycomb cyst expansion.
Keywords: Autopsy; Check-valve mechanism; Cyst expansion; HRCT, High-resolution computed tomography; Honeycomb cyst; IPF, Idiopathic pulmonary fibrosis; Idiopathic pulmonary fibrosis; KL-6, Krebs von den Lungen-6; PFT, Pulmonary function tests; Pulmonary function test; VC, Vital capacity.
© 2022 The Authors.