Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) and the Role of Somatostatin analogs: A Case Series.

Abstract

DIPNECH is a rare pre-neoplastic condition that often presents with a variety of non-specific pulmonary symptoms and sometimes seen in conjunction with pulmonary carcinoid tumors. There are very limited data on use of somatostatin analogs in patients with DIPNECH. We review the long-term outcomes of somatostatin analog therapy with regard to symptom control in patients with DIPNECH. Retrospective study out of our extensive registry of over 2000 neuroendocrine tumors identifies 184 pulmonary neuroendocrine tumors. Out of this, there were five histopathologically confirmed cases of DIPNECH. Appropriate institutional review board permission was taken for this analysis. All 5 patients were females, with a mean age at diagnosis was 65.5 years. Follow-up period includes 1-5 years. Cough was the presenting complaint in all five patients described as mostly dry, except for one patient who had productive early morning cough. Other symptoms seen in one of our patients included wheezing, flushing, and fluctuating blood pressure. No one reported weight loss, hemoptysis, and shortness of breath. One of our patients had a benign thyroid nodule and two patients had previous history of breast cancer. All five of our patients were histopathologically diagnosed by lung biopsy. 4 out of 5 patients were started on a somatostatin analog. All four patients reported drastic improvement in cough. One patient reported mild abdominal discomfort and diarrhea as side effects but remained on treatment. From our single institution review of neuroendocrine pulmonary tumor cases, we found only five cases of DIPNECH, which reaffirms rare nature of the pathology. It primarily affects females over 60 years with dry cough as the most common presenting symptom. Most of our patients responded to treatment with a somatostatin analog and had significant improvement in their presenting symptoms. Somatostatin analogs were well tolerated resulting in significant resolution of presenting symptoms in most of our patients. Further research is needed; however, a trial of somatostatin analogs should be considered in the treatment of patients with DIPNECH with responders being treated long term.