Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: an under-recognized entity—a report of two cases

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary disorder that is classified as a pre-invasive lesion. It can also be present in association with chronic lung diseases. We present two cases of DIPNECH, which were picked up incidentally only on histopathology. A 29-year-old male presented with a history of longstanding cough with expectoration. A computed tomography (CT) scan showed bronchiectasis in the left lung. Histopathological evaluation of the pneumonectomy specimen revealed nests of proliferating, non-infiltrating neuroendocrine cells. Our second patient was a 38-year-old female with chronic cough and expectoration with recent exacerbation. CT scan showed cystic bronchiectasis in the left lower lobe; hence, a lobectomy was performed. On histopathology, nests of non-infiltrating neuroendocrine cells were noted. A diagnosis of DIPNECH with bronchiectasis was offered to both patients, and they have been on follow-up ever since. DIPNECH is a diagnostic and therapeutic quandary requiring a high index of suspicion for its detection and effective surveillance.