Normalization of Elevated CA 19-9 Level after Treatment in a Patient with the Nodular Bronchiectatic Form of Mycobacterium abscessus Lung Disease
A 40-year-old man was referred to our hospital because of chronic cough and sputum. He had been healthy until five years earlier, when cough and sputum developed. He had no history of pulmonary tuberculosis. The patient had no smoking history or other medical history. He appeared relatively healthy, and no signs of fever, chills, weight loss, or digestive symptoms were observed at the time of visit. He was suffering from productive cough, purulent sputum, and right pleuritic pain. His blood pressure was 134/90 mm Hg, pulse rate 78/min, respiratory rate 20/min, and body temperature 36.1℃. Bronchial breathing sound with inspiratory rhonchi was auscultated on the right upper lung field in the thoracic examination. Laboratory results, including immunoglobulin levels, were normal with the exception of elevated serum CA 19-9 to 142.35 U/mL (normal range, <37 U/mL). Pancreas computed tomography (CT) yielded no specific abnormal findings.\nChest radiography revealed cystic changes in the right upper and middle lung zones. A chest CT scan revealed severe bronchiectasis in the right upper lobe and right middle lobe (). There was no evidence of cystic fibrosis or other common causes of bronchiectasis. A sputum Gram stain shows normal flora and routine bacterial culture reveals no pathogens. Numerous acid-fast bacilli were seen in multiple sputum specimens (4+). Nontuberculous mycobacteria were isolated repeatedly from three expectorated sputum specimens and all isolates were identified as M. abscessus by a polymerase chain reaction-restriction fragment length polymorphism method based on rpoB and sequence analysis targeting the rpoB and hsp65 genes. Drug susceptibility testing was performed at the Korean Institute of Tuberculosis by using a broth microdilution method. The isolated M. abscessus was susceptible to amikacin, cefoxitin, clarithromycin, and ciprofloxacin, but resistant to doxycyline.\nThe patient was diagnosed with M. abscessus lung disease, according to the diagnostic guidelines, and began antibiotic therapy with a two-drug oral regimen that included clarithromycin (1,000 mg/day) and ciprofloxacin (1,000 mg/day), along with an initial 4-week course of amikacin (15 mg/kg/day in two divided doses) and cefoxitin (200 mg/kg/day, maximum 12 g/day in three divided doses). Right upper and middle lobectomy was performed because sputum culture was persistently positive after 5 months of antibiotic treatment. Pathologic examinations showed severe bronchiectasis and associated chronic granulomatous inflammation with caseous necrosis. Antibiotics were continued 12 months after surgery. Negative sputum culture conversion was achieved immediately after surgery and was maintained until the completion of antibiotic treatment. The serum CA 19-9 levels returned to the normal range (13.56 U/mL) 1 month after surgery and remained within the normal range (15.51 U/mL) 12 months after surgery ().