A dip into the lungs for endometrial carcinoma evaluation unveiling a rare pulmonary disease

SESSION TITLE: Lung Pathology Case Report Posters 10 SESSION TYPE: Case Report Posters PRESENTED ON: 10/10/2023 09:40 am - 10:25 am INTRODUCTION: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary disorder that is characterized by diffuse hyperplasia of bronchiolar and bronchial pulmonary neuroendocrine cells. It can be difficult to diagnose as it often incidentally found and can present asymptomatically in most cases. Primary neuroendocrine cell proliferation occurs without underlying pathology and typically in non-smoking middle-aged women. CASE PRESENTATION: A 75-year-old G0 postmenopausal female with history of hyperthyroidism, CHF, 10 pack year smoking history and a recent diagnosis of endometrial cancer was found to have 3 indeterminate hypodense hepatic lesions, 1 cm right breast nodule and multiple pulmonary nodules with mosaic attenuation, with the largest being 2.1 cm, in the right lower lobe were seen on CT imaging for metastatic workup. No lymphadenopathy was noted. Patient had symptoms of intermittent vaginal bleeding for 4 months but had no cardiopulmonary symptoms. Further workup reveled large hypermetabolic pulmonary nodule in the right lower lobe and right breast seen on PET scan consistent with metastatic disease. As a result, lung biopsy was pursued and incidentally confirmed DIPNECH. She underwent treatment of her stage IV endometrial cancer and then underwent right lower and upper lobe wedge resection and mediastinal lymph node dissection. DISCUSSION: DIPNECH is a rare premalignant neuroendocrine tumor that occurs mainly in non-smoker middle aged females. Patients' presentation often includes pulmonary symptoms of chronic cough and dyspnea, though can also be asymptomatic as in our case. Pulmonary function test usually reveals an obstructive or mixed obstructive/restrictive ventilatory defect. Purely restrictive or a normal spirometry pattern are rare. CT imaging shows multifocal pulmonary nodules with associated mosaic attenuation, as seen in our case. Diagnosis is made through surgical biopsy. Patients' clinical progression is largely driven by constrictive obliterative bronchiolitis, which typically has an indolent course with progressive respiratory decline and difficult to treat symptoms. Treatment of symptomatic DIPNECH is with somatostatin analog alone or in conjunction with steroids and bronchodilators with improvement in symptoms and pulmonary function tests shown in small studies. Review articles note that CT imaging should be performed every 12–24 months for surveillance with high resolution CT rather than conventional CT to better detect airway-related disease, though no evidence-based guidelines exist. Radiologically, multifocal pulmonary nodules are the most predominant finding, typically found to be along the small bronchovascular bundles in a centrilobular distribution. Nodular distribution is about 75% in the lower lobes. The nodules are non-calcified, round to ovoid with a solid density. 91% of patients also had associated lobular mosaic attenuation, characterized by a patchwork of low attenuation intermixed with normal-appearing lung. Ground-glass and nodular bronchiolocentric opacities are also seen on imaging and typically represent tumorlets. Treatment options include observation, steroids, chemotherapy and lung resection, which our patient underwent. Transplant may be considered in severely symptomatic disease. CONCLUSIONS: DIPNECH remains a rare pulmonary condition. While most patients have an uneventful clinical course, it may be associated with airway obstruction in some cases. Awareness of the condition in conjunction with imaging and histologic findings are required to make definitive diagnosis and pursue treatment. REFERENCE #1: Rossi G, Cavazza A, Spagnolo P, Sverzellati N, Longo L, Jukna A, Montanari G, Carbonelli C, Vincenzi G, Bogina G, Franco R, Tiseo M, Cottin V, Colby TV. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia syndrome. Eur Respir J. 2016 Jun;47(6):1829-41. doi: 10.1183/13993003.01954-2015. Epub 2016 Apr 13. PMID: 27076588. REFERENCE #2: Nassar AA, Jaroszewski DE, Helmers RA, Colby TV, Patel BM, Mookadam F. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: a systematic overview. Am J Respir Crit Care Med. 2011 Jul 1;184(1):8-16. doi: 10.1164/rccm.201010-1685PP. Epub 2011 Mar 25. PMID: 21471097. REFERENCE #3: Little BP, Junn JC, Zheng KS, Sanchez FW, Henry TS, Veeraraghavan S, Berkowitz EA. Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia: Imaging and Clinical Features of a Frequently Delayed Diagnosis. AJR Am J Roentgenol. 2020 Dec;215(6):1312-1320. doi: 10.2214/AJR.19.22628. Epub 2020 Oct 6. PMID: 33021835. DISCLOSURES: No relevant relationships by Firas Abdulmajeed No relevant relationships by Nameer Al-Yousif No relevant relationships by Chelsea Meyer No relevant relationships by Salahuddin Nasir No relevant relationships by Karen Selk