Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia diagnosed by transbronchial lung cryobiopsy: a case report

BACKGROUND Micronodular lesions are common findings in lung imaging. As an important differential diagnosis, we describe a case of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia; it is notable that the diagnosis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia is often delayed. This case provides supporting evidence to establish lung biopsy by cryotechnique as the option of first choice when considering a diagnostic strategy for micronodular lung lesions. CASE PRESENTATION We report a case of a 65-year-old white woman who presented with obstructive symptoms of chronic coughing and dyspnea confirmed by conventional lung function tests. A computed tomography scan presented disseminated micronodules in all the lobes of her lungs. With the help of bronchoscopic cryobiopsy it was possible to obtain a high yield sample of lung parenchyma. On histologic examination, the micronodules correlated with a diffuse neuroendocrine cell hyperplasia. In the context of clinical symptoms, radiological aspects, and histomorphological aspects we made the diagnosis of a diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. Obstructive symptoms were treated with inhaled steroids and beta-2-mimetics continuously. A comparison between current computed tomography scans of our patient and scans of 2014 revealed no significant changes. Last ambulatory checks occurred in January and May of 2016. The course of disease and the extent of limitation of lung function have remained stable. CONCLUSIONS The diagnosis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia is best made in a multidisciplinary review including clinical presentation, lung imaging, and histomorphological aspects. This report and current literature indicate that transbronchial lung cryobiopsy can be used as a safe and practicable tool to obtain high quality biopsies of lung parenchyma in order to diagnose micronodular lesions of the lung.