# Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia: An Uncommon Clinical Challenge

## TL;DR

This paper presents a case of a rare lung condition called DIPNECH, highlighting its diagnostic challenges and treatment options.

## Contribution

The paper contributes a detailed case report emphasizing the importance of histopathological confirmation for DIPNECH.

## Key findings

- DIPNECH often mimics asthma or COPD, leading to delayed diagnosis.
- Histological analysis via VATS biopsy is crucial for confirming DIPNECH.
- Somatostatin analogues may be considered for selected DIPNECH patients.

## Abstract

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare interstitial lung disease characterized by diffuse proliferation of neuroendocrine cells in the airway mucosa and regarded as a preneoplastic condition. It typically affects nonsmoking middle-aged or elderly women and often presents with insidious symptoms like chronic cough, exertional dyspnea, and wheezing. Since these non-specific features may resemble asthma or other obstructive pulmonary airway diseases, the diagnosis is frequently challenging and therefore delayed. Chest high-resolution computed tomography (HRCT) typically shows multiple small pulmonary nodules and a mosaic attenuation pattern, but histological analysis, most reliably obtained by video-assisted thoracoscopic surgery (VATS) biopsy, is the key to establishing the diagnosis.

Herein, we report the case of an elderly woman with a 12-year history of productive cough, exertional dyspnea, and wheezing, initially misdiagnosed as chronic obstructive pulmonary disease (COPD). HRCT revealed multiple small solid nodules and a mosaic attenuation pattern. On physical examination, basal crackles and squeaks were noted on lung auscultation. Following persistent symptoms and inconclusive noninvasive investigations, a VATS lung biopsy was performed, which established the diagnosis of DIPNECH. The patient was treated with systemic corticosteroids and long-acting bronchodilators but developed steroid-related complications without clinical improvement. Follow-up 68Ga-DOTA-NOC (gallium-68-labeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-conjugated somatostatin analog) positron emission tomography/computed tomography (PET-CT) showed low-to-moderate somatostatin receptor expression, and therapy with lanreotide was initiated.

This case illustrates the clinical and diagnostic challenges of this uncommon entity and emphasizes the importance of early suspicion, histopathological confirmation, and consideration of somatostatin analogues in selected patients.