Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary pathology which encompasses a spectrum of findings ranging from simple neuroendocrine cell proliferation to discrete nodules, and is strongly associated with carcinoid tumours. Patients, typically female, are often asymptomatic, but may present with overt pulmonary symptoms, such a dyspnoea, cough or pleuritic chest pain; however, even in their absence, a degree of obstructive or mixed obstructive/restrictive deficit on formal pulmonary function testing is common.
We describe the case of a 60 year old female non-smoker who initially presented with a chronic non-productive cough and right subcostal pain. Whilst obese and hypertensive, pituitary imaging and endocrine function were generally unremarkable, though both FSH and LH were inappropriately low for a post-menopausal woman. A single discrete 2 cm mass in the right upper zone was accompanied by diffuse nodularity throughout both lung fields on CT scanning. Biopsy showed the mass to be a low grade spindle cell carcinoid tumour. Subsequent Video Assisted Thoracic Surgery confirmed the presence of neuroendocrine tumourlets and multiple foci of neuroendocrine cell hyperplasia in the contralateral lung. 68Ga-Octreotate-PET scanning failed to demonstrate any uptake in either the tumour or pulmonary nodules, suggesting no significant somatostatin receptor expression. The patient underwent a right middle lobectomy, and has remained symptomatically well since the procedure. Interestingly, a single subcarinal lymph node showed minimal tracer activity during PET scanning, whilst histologically metastatic spread to a single lymph node was reported.
Although perhaps typical in its presentation, we feel that this case merits reporting, in the hope that it will promote further discussion about the management and surveillance of DIPNECH.