SESSION TITLE: Miscellaneous Student/Resident Case Report Posters II
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare disorder which is considered a preinvasive lesion for carcinoid tumors. A spectrum of pulmonary neuroendocrine cell tumors (NET) ranging from DIPNECH to carcinoid tumorlet to carcinoid tumors exist. We report a case that presented simultaneously with all three varieties of NET.
CASE PRESENTATION: A 66-year-old healthy female presented with productive cough for 6 weeks. Examination was normal. Chest xray showed a 2-cm lung nodule. Chest CTscan revealed multiple lung nodules of varying sizes. A thoracoscopic biopsy was performed which revealed a well-differentiated NET, diagnosed as carcinoid tumor and tumorlets. Intraepithelial neuroendcrine cells (NE) present within smaller airways situated near the carcinoid tumor, was diagnostic of DIPNECH. ChromograninA, Urinary 5HIAA, ACTH, Serotonin levels; Octreotide scan and pulmonary function test were normal. The patient’s cough resolved spontaneously. Without symptoms or evidence of extrathoracic spread, chemotherapy was not initiated. On follow-up 2 years later, she remains asymptomatic without evidence of progression on serial CT scans.
DISCUSSION: DIPNECH is the earliest manifestation of pulmonary NET, characterized by proliferation of NE cells, in the bronchial/ bronchiolar epithelium, and superficial to the basement membrane (BM). In tumorlets, proliferating NE cells extend beyond the BM and form nests <5 mm in size. Carcinoid tumors are >5mm. CT scan typically shows multiple pulmonary nodules. It is essential to differentiate NETs from metastatic disease and other etiologies. DIPNECH is typically seen in women in their 6th decade. Patients may be asymptomatic or present with respiratory symptoms including cough, wheezing, dyspnea, hemoptysis, or pleuritic chest pain. Pulmonary function tests often show obstruction. Chest CT scan typically shows multiple tiny pulmonary nodules and the presence of small airway obstruction in the form of mosaic attenuation. Generally patients with DIPNECH have good long-term survival given its indolent nature. Management involves close follow up however, if symptoms of obstructive airway progress a trial of steroids may be useful. A subset of DIPNECH-patients also have carcinoid tumor/tumorlet. Presentation is similar. Peripherally located carcinoids are more likely to be incidentally found. Carcinoid syndrome is seen in <5% of lung NETs. The primary treatment of carcinoid tumors is surgical resection. These tumors are generally resistant to chemotherapy and radiation making surgery the best option even when metastases is present. The survival for carcinoid tumor with intrathoracic spread is fair.
CONCLUSIONS: Diffuse lung involvement in NET may suggest metastatic disease, from which it can be differentiated by pathology and chemical tests. When confined to the thorax, it has a fair prognosis.
Reference #1: Davies SJ et al.DIPNECH. Thorax 2007; 62:248.
Reference #2: Koo CW et al. AJR 2010;195:661
DISCLOSURE: The following authors have nothing to disclose: Natalie Berger, Julianne Nichols, D. Datta
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