[Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia/tumorlets]

Area of Science:

• Pulmonology
• Endocrinology
• Pathology

Background:

• Diffuse idiopathic hyperplasia of neuroendocrine cells (DIHNE) is an exceptionally rare condition characterized by widespread, unprovoked neuroendocrine cell proliferation.
• While often symptomatic, asymptomatic presentations of DIHNE also occur, posing diagnostic challenges.

Purpose of the Study:

• To report three distinct cases of DIHNE presenting with bilateral pulmonary nodules.
• To discuss the diagnostic difficulties and clinical management of this rare entity.

Main Methods:

• Case series describing three patients (2 female, 1 male) with DIHNE.
• Review of clinical presentations, diagnostic procedures including lung biopsies, and treatment outcomes.
• Analysis of associated symptoms like cough, dyspnea, and paraneoplastic syndromes.

Main Results:

• Two patients diagnosed with DIHNE-tumorlets, one with co-existing typical carcinoid tumor and DIHNE.
• Symptomatic relief achieved with bronchodilators in one case; another experienced severe respiratory failure and paraneoplastic syndromes managed with octreotide.
• One patient remained asymptomatic under follow-up.

Conclusions:

• DIHNE presents a significant diagnostic challenge due to its rarity and varied presentations.
• Lung biopsy is crucial for diagnosing DIHNE in patients with bilateral pulmonary nodules and relevant respiratory symptoms.
• Prompt recognition and management, including addressing potential paraneoplastic phenomena, are vital for patient outcomes.