Interstitial Lung Disease Presenting with Bilateral Pulmonary Nodules

Introduction: Interstitial Lung Disease (ILD) is the heterogenous group of disease that share similar clinical, radiological and physiological findings and hence mostly grouped together. Radiologically, they present with varied findings which includes ground glass opacity, reticulations, honey combing, septal thickenings or the combination of these findings. Some specific combination could lead to the diagnosis of a particular ILD provided radiological findings match the clinical presentations. We present a patient who came with chronic cough and shortness of breath and CT chest showed anterior mediastinal mass with bilateral pulmonary nodules. Surgical lung biopsy revealed cellular NSIP (nonspecific interstitial pneumonia) and LIP (lymphoid interstitial pneumonia). Case: A 30-year-old female presented to the hospital with progressive dyspnea for approximately 3 weeks that had worsened and was associated with decreased exercise tolerance. All routine laboratory workup was unremarkable. Inflammatory markers like CRP, ESR, LDH were slightly elevated. COVID-19 test was negative. A CT angiography of the thorax demonstrated an 8cm anterior right upper lobe pulmonary mass with numerous pulmonary nodules in bilateral lung fields. MRI of the brain, bone scan and CT scan of the abdomen and pelvis did not demonstrate any evidence of metastatic disease. A CT-guided core needle biopsy of the anterior lung mass was performed as well as several rheumatologic blood tests. Antinuclear antibody was positive with elevated RNP antibody 3.2 (reference <1), elevated autoantibodies to SS-A/Ro 6.5 (reference <1). The pathology of the core needle biopsy of the anterior lung mass was positive for thymoma. A video assisted thoracoscopic surgery of the lung was performed. The pathology of the pulmonary nodules was positive for overlapping features of cellular nonspecific interstitial pneumonia and LIP. The diagnoses of Sjogren's related interstitial lung disease and thymoma were made. She was treated with mycophenolate and prednisone. Discussion: NSIP is primarily idiopathic however it can be found in association with connective tissue disorders including Sjogren's disease, lupus, dermatomyositis, and polymyositis. CT findings for NSIP often show traction bronchiectasis with symmetric and bilateral ground-glass opacities with no honeycombing. This case above describes a patient with bilateral pulmonary nodules that were initially thought to be metastatic from her accompanying anterior chest wall mass. Although considered very rare, anterior chest wall masses that are associated with connective tissue diseases include thymoma, thymic cyst, teratoma, and thymic carcinoma. Our patient had a rare presentation of Sjogren associated interstitial lung disease and thymoma with atypical CT findings of NSIP.