Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: 7-year follow-up of a rare clinicopathologic syndrome

Abstract

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare clinical pathological syndrome. There have been only 49 cases of DIPNECH reported in the literature so far. We report a case of a 69-year-old nonsmoking man with a 7-year follow-up. The initial CT scan from December 2003 showed persistent nonspecific bilateral reticulonodular infiltrates. In January 2004, the patient underwent a video-assisted thoracoscopic wedge resection of his right lower lobe for further diagnostic workup. Pathology of the resected wedge of the right lower lobe revealed a diffuse idiopathic pulmonary cell hyperplasia (DIPNECH) highlighted by staining for the neuroendocrine typical carcinoid markers, such as marker CD 56. All the performed CT scans over a 7-year period showed no progression of the bilateral pulmonary lesion. The bilateral pulmonary nodules were stable in terms of size, number and form. The yearly control with chest CT scans will be continued. The neuroendocrine cell hyperplasia is confined to the airway mucosa without penetration through the basement membrane and appears in a diffuse pattern, generally in close association with obliterative bronchiolar fibrosis. DIPNECH is characterized by a mixed obstructive and/or restrictive ventilation pattern with bilateral reticulonodular infiltrates and a predilection for middle-aged women. Little is known about the clinical course and treatment for DIPNECH.