Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia with pulmonary carcinoid tumor
Presentation
Non-smoker. On immunosuppressant therapy. Follow-up.
Patient Data
There are numerous, well-delineated intrapulmonary nodules and micronodules present throughout both lungs.
Diffuse ground glass opacities are noted with lower lobe predominance.
A soft tissue mass of 2.5 cm is detected at the left hilum abutting the main pulmonary artery.
Restaging CT study following radiotherapy shows focal perihilar radiation fibrosis with bronchiectasis. The diffuse ground-glass mosaic attenuation became even more evident.
FDG-PET CT denotes a focus of activity at the left perihilar soft tissue adjacent to left main pulmonary artery, compatible with malignancy. The multiple bilateral pulmonary nodules demonstrate no or low avidity.
Case Discussion
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare lung condition characterized by the abnormal overgrowth of pulmonary neuroendocrine cells, of which this patient had histological proof. Usually, aspecific symptoms occur such as a chronic, non-productive cough, shortness of breath with exertion and wheezing.
It is considered to be a precancerous condition for pulmonary carcinoid tumors (well-differentiated neuroendocrine tumors). FDG PET CT can be helpful distinguishing between benign nodules and the ones showing malignant transformation.
The presence of scattered multiple, rounded and ovoid pulmonary nodules and micronodules with mosaic pattern ground-glass opacities might raise the suspicion of DIPNECH.