The pathological definition published by the World Health Organization is “a generalized proliferation of scattered single cells, small nodules (neuroendocrine bodies), or linear proliferations of pulmonary neuroendocrine (PNE) cells that may be confined to the bronchial and bronchiolar epithelium.”[1] The true prevalence of this disease is not known.
DIPNECH is usually discovered in one of two ways: 1) as an unexpected finding following a lung surgery; or 2) by evaluation of a patient in a pulmonary clinic with longstanding, unexplained symptoms.
Erroneous initial diagnoses of asthma or chronic obstructive pulmonary disease often are made in patients with DIPNECH.
[8] In most DIPNECH cases, upon examination of the lung tissue, the overgrowth of pulmonary neuroendocrine cells is seen along the small airways, with extension through the basement membrane of the bronchiolar epithelium leading to formation of carcinoid tumorlets.
Upon microscopic examination, the PNE cells have round, oval, or spindle nuclei with salt-and-pepper chromatin and clear or eosinophilic cytoplasm.
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.
[3] When isolated bronchial carcinoids are diagnosed, oncology guidelines recommend surgical resection with lymph node sampling.
The lung disease tends to be slowly progressive, but given enough time can lead to significant disability and require supplemental oxygen therapy.