DIPNECH: The neuroendocrine enigma behind persistent respiratory symptoms in the post-COVID era

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) is an underrecognized lung disease that hides in plain sight, often misdiagnosed as asthma or COPD. Its early symptoms such as chronic cough, wheezing, and dyspnea are deceptively nonspecific, leading to diagnostic delays even in patients with classic risk factors like middle-aged, non-smoking females. In one illustrative case, a woman developed unexplained respiratory symptoms following COVID-19, eventually leading to a diagnosis of DIPNECH after incidental imaging revealed pulmonary nodules. The hallmark feature is airway-centered neuroendocrine cell proliferation, which can exist with or without tumorlets or progression to carcinoid tumors. Though symptoms may respond to bronchodilators or corticosteroids, unchecked progression may result in irreversible airflow obstruction. Recognizing DIPNECH early is crucial for timely intervention. When common diagnoses do not fully explain the clinical picture, DIPNECH deserves a place on the differential.