A 57-year-old man was admitted to our hospital with a high
fever and productive
cough. He had a previous history of total
gastrectomy and
splenectomy at the age of 45 years due to
gastric cancer. He also showed severe
macrocytic anemia with low
vitamin B12, and an infiltrative shadow was found in the right lung on an X-ray. Sputum examination on admission revealed no significant pathogenic bacteria, and an
acid-fast
stain and a M.
tuberculosis PCR test were negative. QuantiFERON TB-2G Test (QFT) was negative on admission. Because pneumococcal
antigen in the urine was positive, we initially diagnosed
pneumococcal pneumonia and treatment with
antibiotics was started. However, symptoms were not resolved with several
antibiotics, finally, a thoracoscopic lung biopsy under
general anesthesia was performed for a definitive diagnosis. The biopsy showed epithelioid cell
granuloma in the alveolar spaces, and the 8 weeks culture of sputum taken on admission revealed M.
tuberculosis. Finally, a
pulmonary tuberculosis was diagnosed and treatment with four drugs of HERZ was begun. We have encountered a case of
pulmonary tuberculosis combined with a lobar
pneumococcal pneumonia, and negative for QFT. In general,
splenectomy is known as a risk factor of
pneumococcal infection. And
vitamin B12 deficiency due to
gastrectomy is one of the risk factors for cellular immunity impairment and was possibly to the false negative QFT and development of TB.