A Rare Case of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) in a Filipino Woman: A Case Report and Review of Literature

Abstract

Diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH) is a rare condition in which few case reports have been published describing the disorder and its prognosis to date. DIPNECH is described as a diffuse abnormal proliferation of neuroendocrine cells found in the lining of the lower respiratory system. It typically occurs in non-smoking, middle-aged women and is believed to occur spontaneously with no known precursor. DIPNECH is considered to be a premalignant lesion that potentially develops into a carcinoid tumor of the lungs. We present a case of a 66-year-old Filipino woman diagnosed with breast carcinoma with an incidental finding of a round lung density in the right paravertebral region (T10-11) seen on chest X-ray. Further imaging study using a chest CT scan showed multiple non-calcified nodules in the right middle and both lower lobes with no involvement of the airways were noted. She underwent CT-guided biopsy of the dominant lung nodule and was noted to be positive for synaptophysin, chromogranin, CD-56, and a Ki-67 of 1–3%, which is consistent with a typical carcinoid tumor. Video-assisted thoracic surgery (VATS) with wedge resection of the right and middle lobes was performed. The background lung tissue on biopsy revealed neuroendocrine tumorlets measuring 0.1 to 0.4 cm. After the multidisciplinary consultation, it was agreed to preserve the remaining lung parenchyma with monitoring using a chest CT scan, and pulmonary function test with diffusing lung capacity for carbon monoxide (DLCO) every 6 months was advised. At present, the patient remains asymptomatic. To our knowledge, there is no published case of DIPNECH in the Filipino population and no available data on morbidity and mortality, especially in the local setting. A multidisciplinary approach to diagnosis and management is highly recommended. It has been observed to have a slow progression; thus close monitoring and strict follow-up should be advised. Currently, lung preservation is the goal of management.