Previously,

Kawabata et al. reported that distinct lobular distribution and architectural destruction with thin-walled cyst formation are characteristic features of DIP. They also found a marked increase in the number of BAL eosionophils in patients with DIP, although the significance of BAL eosinophilia is not yet fully understood [8]. Our patient did not exhibit these findings. Moreover, the prominent accumulation of intraalveolar macrophages with diffuse distribution throughout the pulmonary acini, which selleckchem is a hallmark of DIP, was not observed in the biopsy specimen. CPFE is a newly defined syndrome, in which upper lobe emphysema (> 10% of the lung volume) coexists with significant pulmonary fibrosis in the lower lobe defined by honeycombing, reticular opacities, and/or traction bronchiectasis on HRCT. CPFE has been receiving considerable attention because pulmonary hypertension and severe reductions in diffusion capacity are highly prevalent in CPFE. Although the pathology of CPFE is heterogeneous including DIP, organizing pneumonia, and unclassifiable interstitial pneumonia, UIP is the most common pattern and biopsy-proven NSIP has not XL184 cell line yet been reported [10]. The HRCT findings

of our case were milder in both emphysematous and interstitial changes than typical CPFE. However, this case may have progressed to a type of CPFE if the patient continued to smoke. Katzenstein et al. recently documented clinically occult SRIF in lobectomy specimens. This distinct form of fibrosis is composed of thick hyalinized collagen bundles, often with variable numbers of hyperplastic smooth muscle fibers without significant inflammation [11]. The pathological findings of our patient were not consistent with these criteria. Drug-induced NSIP is rare and NSIP may also be caused by the inhalation of high levels of mold and/bacteria [12]. However, in our case, no changes in drug ingestion, Tolmetin living environment, or habits were reported

during the clinical course, except for the complete cessation of smoking. The diagnosis of idiopathic NSIP in this patient was appropriate from the above-mentioned points of issue. The reason why similar cases have not been reported previously in spite of its relatively high incidence rate may be that the definite diagnosis of NSIP by surgical biopsy was not made before relatively advanced morphological abnormalities were confirmed by HRCT. We performed surgical biopsy in this patient with mild interstitial changes and normal pulmonary function. Early smoking cessation before a clinically detectable decline in pulmonary function may be critical for smokers with idiopathic NSIP.