Cavazza, Alberto

The diagnostic criteria of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) are not well defined, and DIPNECH can be mistaken for carcinoids associated with neuroendocrine cell hyperplasia (NECH). In this study, we compared clinical, radiologic, histologic, immunohistochemical, and molecular features of DIPNECH and isolated carcinoids with/without NECH. The study population included 151 cases (77 female patients and 74 male patients), 19 with DIPNECH and 132 with carcinoids with/without NECH. None of the cases displayed molecular alterations or anaplastic lymphoma kinase expression. Compared with individuals with carcinoids with/without NECH, patients with DIPNECH were more likely to be female individuals ( P <0.0001), nonsmokers ( P =0.021), and symptomatic, and to have an obstructive/mixed respiratory defect, peripheral location of the lesions, and air trapping ( P <0.0001) on chest computed tomography, and constrictive bronchiolitis on histology ( P <0.0001). Among immunohistochemical markers, DIPNECH was associated with higher expression of thyroid transcription factor-1, CD10, and gastrin-releasing peptide/bombesin-like peptide ( P <0.0001). Yet, when a purely histopathologic definition of DIPNECH was applied, 40% of isolated carcinoids also met the diagnostic criteria for DIPNECH, even in the absence of symptoms and/or radiologic abnormalities. Therefore, as DIPNECH represents a distinct clinical syndrome, we suggest the term DIPNECH be limited to cases presenting with respiratory symptoms, functional and/or radiologic abnormalities, and constrictive bronchiolitis on histology.

Context.— Transbronchial cryobiopsy has recently been proposed as an alternative to surgical biopsy in the diagnosis of diffuse lung disease. Objective.— To familiarize pathologists with transbronchial cryobiopsy, including what it is, how it is performed, how it compares to other techniques of lung biopsy in diffuse lung disease, what are the technical issues relating to it, what the complications are, how cryobiopsies should be interpreted, and the clinical usefulness of cryobiopsy. Data Sources.— All the available literature on cryobiopsy in diffuse lung disease through May 2016, primarily in the last 5 years, was reviewed, and some unpublished data known to the authors were included. Conclusions.— Cryobiopsies are considerably larger than forceps biopsies and allow pattern recognition approaching that of a surgical lung biopsy in many cases. Artifacts associated with cryobiopsy are minimal. In comparison with surgical lung biopsies, the diagnosis rate with cryobiopsies is lower, in the neighborhood of 80%, versus higher than 90% for surgical lung biopsies. Cryobiopsy is proposed as an alternative to surgical lung biopsy and a technique that may appreciably decrease the number of patients who require surgical lung biopsy for diagnosis. This is important because the mortality from cryobiopsy is very small (0.1% to date) compared with surgical lung biopsy (1.7% for elective procedures and considerably higher for nonelective procedures).

Abstract Rationale Surgical lung biopsy is often required for a confident multidisciplinary diagnosis of idiopathic pulmonary fibrosis (IPF). Alternative, less-invasive biopsy methods, such as bronchoscopic lung cryobiopsy (BLC), are highly desirable. Objectives To address the impact of BLC on diagnostic confidence in the multidisciplinary diagnosis of IPF. Methods In this cross-sectional study we selected 117 patients with fibrotic interstitial lung disease without a typical usual interstitial pneumonia pattern on high-resolution computed tomography. All cases underwent lung biopsies: 58 were BLC, and 59 were surgical lung biopsy (SLB). Two clinicians, two radiologists, and two pathologists sequentially reviewed clinical-radiologic findings and biopsy results, recording at each step in the process their diagnostic impressions and confidence levels. Measurements and Main Results We observed a major increase in diagnostic confidence after the addition of BLC, similar to SLB (from 29 to 63%, P = 0.0003 and from 30 to 65%, P = 0.0016 of high confidence IPF diagnosis, in the BLC group and SLB group, respectively). The overall interobserver agreement in IPF diagnosis was similar for both approaches (BLC overall kappa, 0.96; SLB overall kappa, 0.93). IPF was the most frequent diagnosis (50 and 39% in the BLC and SLB group, respectively; P = 0.23). After the addition of histopathologic information, 17% of cases in the BLC group and 19% of cases in the SLB group, mostly idiopathic nonspecific interstitial pneumonia and hypersensitivity pneumonitis, were reclassified as IPF. Conclusions BLC is a new biopsy method that has a meaningful impact on diagnostic confidence in the multidisciplinary diagnosis of interstitial lung disease and may prove useful in the diagnosis of IPF. This study provides a robust rationale for future studies investigating the diagnostic accuracy of BLC compared with SLB.