DIFFUSE CYSTIC LUNG DISEASE SECONDARY TO METASTATIC COLON CANCER

Abstract

TOPIC: Diffuse Lung Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Diffuse cystic lung diseases (DCLD) encompass a group of lung disorders characterized by multiple spherical densities with a thin well-defined wall adjacent to normal lung tissue1. Causes of DCLD include lymphoproliferative disorders, interstitial lung diseases, infections, developmental defects, and smoking. Rarely, DCLD can be the result of a malignant process. We report a case of DCLD resulting from metastatic colorectal adenocarcinoma. CASE PRESENTATION: A 49-year-old male former smoker with past medical history significant for advanced colon cancer on palliative chemotherapy with FOLFOX and bevacizumab presented to our facility with several week history of progressively worsening generalized weakness, fatigue, weight loss, cough and shortness of breath. On presentation, the patient was tachycardic and tachypneic with oxygen saturation of 92% on 3 liters nasal cannula O2. Initial laboratory studies noted white blood cell count 12.0, procalcitonin 2.37, c-reactive protein 2.99, and sedimentation rate 50. CTA pulmonary showed extensive, bilateral cystic changes and bilateral interstitial opacities which were significantly worse when compared to chest imaging done three months prior. DISCUSSION: Given the patient's smoking history, known history of colon cancer, and radiologic picture, pulmonary Langerhans cell histiocytosis (PLCH) and metastatic lung disease were considered likely etiologies. The patient was initially started on empiric antibiotics and subsequently underwent bronchoscopy with bronchoalveolar lavage (BAL). Initial BAL fluid studies noted 256 leukocytes with lymphocytic predominance. Gram stain and respiratory cultures were negative. Cytology then resulted with malignant cells consistent with metastatic adenocarcinoma. At this point, the patient's oncologist and palliative care were consulted. Given the patient's overall poor prognosis, the decision was made to pursue home hospice and the patient was discharged home. CONCLUSIONS: Review of the medical literature notates only one previous case of DCLD from metastatic colorectal adenocarcinoma making this a rare pathophysiologic phenomenon2. Neoplastic causes of DCLD include lymphangioleiomyomatosis, PLCH, and other primary and metastatic cancers1. A multi-disciplinary team effort including both pulmonology and oncology should be sought in order to formulate an appropriate treatment plan. Treatment options are based on the underlying etiology of the DCLD. Unfortunately, in this case, patient's disease process was already advanced and palliative care was pursued. REFERENCE #1: 1. Gupta, N., Vassallo, R., Wikenheiser-Brokamp, K. A., & McCormack, F. X. (2015). Diffuse Cystic Lung Disease. Part I. American journal of respiratory and critical care medicine, 191(12), 1354–1366. https://doi.org/10.1164/rccm.201411-2094CI REFERENCE #2: 2. Fielli, M., Avila, F., Saino, A., Seimah, D., & Fernández Casares, M. (2016). Diffuse cystic lung disease due to pulmonary metastasis of colorectal carcinoma. Respiratory medicine case reports, 17, 83–85. https://doi.org/10.1016/j.rmcr.2015.12.006 DISCLOSURES: No relevant relationships by Comfort Adewunmi, source=Web Response no disclosure on file for Yalew Debella; No relevant relationships by Henry Ogbuagu, source=Web Response No relevant relationships by Sameena Salcin, source=Web Response no disclosure on file for Molla Teshome