RT Journal Article SR Electronic T1 Clinical course and changes in high-resolution computed tomography findings in patients with idiopathic pulmonary fibrosis without honeycombing JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA4848 DO 10.1183/13993003.congress-2015.PA4848 VO 46 IS suppl 59 A1 Hiroyoshi Yamauchi A1 Masashi Bando A1 Tomohisa Baba A1 Kensuke Kataoka A1 Yoshikazu Inoue A1 Yoshihito Yamada A1 Hiroshi Yamamoto A1 Kentaro Watanabe A1 Yasuhiro Terasaki A1 Akira Hebisawa A1 Yoshinori Kawabata A1 Takeshi Johkoh A1 Fumikazu Sakai A1 Yukihiko Sugiyama A1 Takashi Ogura YR 2015 UL http://erj.ersjournals.com/content/46/suppl_59/PA4848.abstract AB Background: Some idiopathic pulmonary fibrosis (IPF) patients are histologically diagnosed with usual interstitial pneumonia (UIP) pattern and show lack of honeycombing on high resolution computed tomography (HRCT) . Clinical course and the changes in HRCT findings of these IPF patients are unknown.Aims and objectives: The purpose of our study was to retrospectively assess the changes in HRCT pattern in IPF patients, who were diagnosed with UIP pattern by histology and show lack of honeycombing by HRCT in initial evaluation, and to clarify their clinical course and prognosis.Methods: We evaluated IPF patients without honeycombing on HRCT and who were histologically diagnosed with UIP pattern on the basis of surgical lung biopsy between 1991 and 2010. Multidisciplinary discussions were held 5 times between 2011 and 2014 to evaluate the disease changes as assessed by HRCT and clinical course of these patients.Results: Thirty patients were evaluated by 2014. Sixteen patients demonstrated emerging honeycombing (Group A) and 12 patients demonstrated emerging traction bronchiectasis or cyst without honeycombing (Group B) by HRCT. Two cases were considered as no change (Group C) by HRCT. The mean survival times of Groups A and B were 67.1 and 61.2 months which were not significantly different (p=0.76) .Conclusions: Some IPF patients may not demonstrate honeycombing on HRCT even if they have advanced stage IPF. Our study suggests that there is no difference in prognosis of IPF between cases with honeycombing on HRCT and those without.