DIPNECH: A UNIQUE PRESENTATION OF A RARE DISEASE

Abstract

SESSION TITLE: Diffuse Lung Disease 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 pm - 02:15 pm INTRODUCTION: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a very rare disease that consists of a proliferation of scattered single cells, small nodules, or linear proliferations of pulmonary neuroendocrine cells (1). The entity has been described as a precursor to pulmonary carcinoid tumors (2), is thought to be more common in middle-aged women, and can be associated with slowly-progressive cough or shortness of breath with exertion (1,3). CASE PRESENTATION: We present a case of a 42-year-old female with a complicated pulmonary history including a childhood diagnosis of asthma, two spontaneous pneumothoraces, chronic daily cough, dyspnea on exertion, and a seven-year history of incidentally-noted pulmonary nodules. An initial workup for her nodules was negative for fungal or autoimmune etiologies. An interval CT scan was obtained and showed an increase in nodule size which was further evaluated with a PET-CT. While none of the lung nodules were PET-avid, a hypermetabolic thyroid nodule was incidentally noted, which was biopsied and found to be papillary thyroid cancer. Pulmonary function testing was obtained for her dyspnea and showed mild restriction with no evidence of obstruction and normal diffusion capacity. After a non-diagnostic CT-guided biopsy of a right middle lobe lung nodule led to an iatrogenic pneumothorax requiring chest tube placement, she eventually underwent video assisted thoracoscopic surgery and right middle and lower lobe wedge resections. Biopsy showed the presence of a typical carcinoid tumor as well as neuroendocrine hyperplasia consistent with DIPNECH. DISCUSSION: This case represents an atypical presentation of a rare disease. Though pulmonary nodules, shortness of breath, and cough are common findings in DIPNECH, the occurrence of spontaneous pneumothoraces is not. Few case reports have described spontaneous pneumothoraces in patients with large endobronchial carcinoid tumors; however, this patient had no evidence of endobronchial obstruction and thus represents a unique presentation of the disease (4,5). This case also demonstrates the importance of maintaining a broad differential in the approach to patients presenting with dyspnea, cough, and pulmonary nodules. While the DIPNECH is very rare, appropriate diagnosis and close follow-up is important given the association of DIPNECH with subsequent development of carcinoid tumors (6). CONCLUSIONS: The differential for diffuse pulmonary nodules in the setting of chronic cough or dyspnea is incredibly broad. After more common etiologies like metastatic disease, granulomatous disease, autoimmune, and infectious disorders are ruled out, one should consider the diagnosis of DIPNECH, particularly in a middle-aged female with chronic, otherwise-unexplained respiratory symptoms and especially with an associated diagnosis of a carcinoid tumor (2). Reference #1: Travis WD, Brambilla EW, Burke AP, et al. WHO Classification of Tumours of the Lung, Pleura, Thymus, and Heart, IARC Press, Lyon 2015. Reference #2: Gorshtein, A., Gross, D. J., Barak, D., Strenov, Y., Refaeli, Y., Shimon, I. and Grozinsky-Glasberg, S. (2012), Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and the associated lung neuroendocrine tumors. Cancer, 118: 612–619. https://doi.org/10.1002/cncr.26200. Reference #3: Nassar A. A., Jaroszewski D. E., Helmers R. A., Colby T. V., Patel B. M., Mookadam F. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia—a systematic overview. American Journal of Respiratory and Critical Care Medicine. 2011;184(1):8–16. https://doi.org/10.1164/rccm.201010-1685pp. DISCLOSURES: No relevant relationships by Carleen Risaliti, source=Web Response No relevant relationships by Kyle Stinehart, source=Web Response