Co-Existent Epidermal Growth Factor Receptor Positive Metastatic Lung Adenocarcinoma with Pulmonary Tuberculosis

Abstract

57-year-old male resident of Gilgit and worker at a medical dispensary wasdiagnosed to have pulmonary tuberculosis (PTB) and was on anti-tuberculoustreatment (ATT) for 3 weeks. He had a 20 pack-years cigarette smoking history, without any medical co-morbid conditions. He came to emergency department with worsening of dyspnea, cough, sputum & weight loss and required oxygen inhalation to maintain saturation. His chest radiology revealed bilateral diffuse pulmonary nodules; current 3 sputa smears were negative for acid fast bacilli (AFB) and spirometry had restrictive pattern. Histopathology oftransbronchial biopsies (under fluoroscopy) was consistent with metastaticlung adenocarcinoma and bronchial washings (negative for AFB staining) werepositive for mycobacterium tuberculosis complex without resistance torifampicin (GeneXpert MTB/Rif assay). Molecular analysis of biopsy tissue waspositive for epidermal growth factor receptor (EGFR) mutation showing exon-19 deletion. Besides continuing oxygen and ATT, tyrosine kinase inhibitor (TKI)drug erlotinib was started. He showed remarkable improvement in dyspnea,gained weight and was off oxygen for 12 months along with considerableradiological clearing of lesions. After one year, he was hospitalized again dueto intractable dyspnea, respiratory failure and worsening in radiologicalshadows and passed away.