Zebra Among Horses: A Rare Cause of Common Cough and Dyspnea!

Abstract

INTRODUCTION: Although there are several common causes of dyspnea and cough, ocasionally a rare disease may present with these common symptoms. An open mind and agressive investigation may lead to diagnosis as in our case. CASE PRESENTATION: A 50 year old woman presented with complaints of mild dyspnea on exertion and dry cough. She was treated for possible asthma, allergies and GERD including a trial of prednisone with no improvement. In the next two years, her cough and dyspnea became debilitating. PFT's showed FEV1: 1.03L (36% predicted); FVC: 1.22L (34% predicted); TLC: 3.36L (68%) and DLCO 59%, suggesting a restrictive disease. CT scan of chest was normal. She was then referred to our center. She had no other medical problems, and was allergic to dust. She worked in a departmental store but denied any exposures. Her current medications include desipramine. She had 1 pack year history of smoking and has a dog at home. Vital signs include a BMI of 34 kg/m2 and oxygen saturation of 97% on room air. Lung exam was significant for bibasilar crackles. Routine labs were normal. Echocardiogram showed mild diastolic dysfunction. Video assisted thoracoscopic lung biopsy revealed mild chronic bronchiolitis associated with neuroendocrine cell hyperplasia and tumorlet formation. Airways showed chronic inflammation, mural thickening, and mucus stasis in cells. A diagnosis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) with tumorlets was made (ImagesA-D). DISCUSSION: DIPNECH is a very rare disease with only around a 100 cases reported so far. Most patients are nonsmoking women in their 50's- 60's. Symptoms may be present for many years and include nonproductive cough (71%), dyspnea (63%) or wheezing (25%) (1). PFT's may show obstructive or restrictive pattern. Common findings on CT/HRCT include a mosaic pattern due to bronchiolitis and gas trapping, nodules of varying sizes. Lung biopsy is quintessential for diagnosis. CONCLUSIONS: Clinical course: Our patient is stable, and in fact beginning to exercise and be more active with oxygen, although much less than her baseline a few years ago. Plan is to follow her closely with serial PFT's and CT scan of chest to check for tumor formation. If her disease were to progress we would consider treating with biological agents. She has been referred to lung transplant clinic as well to start work up. Clinical pearls: Our patient had severe symptoms despite a normal CT scan and restrictive physiology. Only because we pursued further work up with a lung biopsy, were we able to make a diagnosis.