The major criterion for diagnosis is typically a confirmed surgical biopsy. Minor diagnostic criteria have been proposed for<unk> . * Clinical presentation: woman, between the age of 45 and 67 with cough and/or shortness of breath for 5–10 years * Pulmonary function: increased residual volume, increased total lung capacity, fixed obstruction, low<unk> ng capacity of the lung for carbon monoxide that corrects with alveolar volume * High-resolution CT scan:<unk>  pulmonary nodules 4–10 mm, greater than 20 nodules, mosaic attenuation or air trapping in greater than 50% of the lung * Transbronchial biopsy: proliferation of pulmonary neuroendocrine<unk> s * Serum markers: elevated serum chromogranin A levels Pathology In most<unk>  cases, upon examination of the lung tissue, the overgrowth of pulmonary neuroendocrine<unk> s is seen along the small airways, with extension through the basement membrane of the bronchiolar epithelium leading to formation of carcinoid tumorlets. When the tumorlets become greater than 5mm in size they are considered bronchial carcinoids. Upon microscopic examination, the PNE<unk> s have round, oval, or spindle nuclei with salt-and-pepper chromatin and clear or eosinophilic cytoplasm. Although no formal definition exists regarding the extent of PNE hyperplasia necessary for a<unk>  diagnosis, this process is often seen throughout the small airways. Because the hyperplasia of PNE<unk> s can be seen as a reaction to chronic lung disease, surrounding solitary bronchial carcinoids and adenocarcinoma of the lung, these causes must be excluded prior to a DIPENCH diagnosis. Obstructive bronchiolitis has been reported as a characteristic histopathologic finding in patients with<unk> . The bronchiolitis is thought to be a response of the small airways to neuropeptides secreted by the PNE<unk> s. Imaging The findings on chest imaging in<unk>  patients are bilateral and<unk> . The most frequent findings on a computed tomography (CT) of the chest are multiple primary nodules and/or masses, on a background of mosaic attenuation and airway wall thickening. The nodules have an indolent pattern of growth and are found throughout the lungs. The nodules are typically rounded and well-defined. Upon surgical resection, histologically the nodules are found to be typical carcinoids or carcinoid tumorlets depending on size. Pulmonary function studies Although some patients present with normal lung function, pulmonary function tests generally demonstrate fixed airway obstruction with a decreased FEV1 and reduced FEV1/FVC ratio without bronchodilator response. Air trapping is common and leads to increased residual volumes. As the disease progresses, a mixed pattern of obstruction and restriction may develop. In general the obstructive lung disease is slowly progressive with periods of stability.
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia
Granulomatous–lymphocytic interstitial lung disease
Pulmonary atypical adenomatous hyperplasia
Atypical pulmonary carcinoid tumour
Mycobacterium avium-intracellulare infection
Pulmonary neuroendocrine tumor
Pulmonary hyalinizing granuloma
Combined pulmonary fibrosis and emphysema