[Study on clinico-pathological features of active pulmonary tuberculosis found at autopsy in a general hospital]

To clarify clinico-pathological features of tuberculosis found at autopsy.

This study investigates 18 (3.7%) of active pulmonary tuberculosis out of 489 autopsy in Tachikawa Sougo Hospital during the period from 1992 to 2005.

There were 11 men and 7 women, with a median age of 69.5 years. Tubercle bacilli were proved from sputum in 6, which consisted of 3 with positivity on sputum smear microscopy and culture, and 3 with positivity only on sputum culture. Two were examined, but not diagnosed before death. Three didn't show any positive result despite of repeated sputum tests. The features of the chest radiological findings were: (1) Shadows that present prior tuberculosis (ex: nodules, fibrotic lesion) were found in 9 and ground-glass-opacity in 5. (2) In 6, radiological findings consistent with tuberculosis were not pointed out because shadows such as fibrosis, pleural effusion, or cancer were mixed in the same lung. (3) In 11, main radiological findings were found in atypical segments, when there were some underlying conditions such as the use of corticosteroidal therapy or diabetes mellitus. Four were diagnosed correctly, and treated with anti-tuberculosis drugs. Other 14 were not diagnosed before death and diagnosed wrongly as pneumonia, cancer, or other diseases. Encapsulated caseous nodules were seen in 7, and autopsy confirmed that 12 including these 7 were caused by endogenous reactivation. Miliary tuberculosis was found in 5, caseous pneumonia/bronchitis in 6. One had tuberculous empyema. As to underlying diseases, 8 had malignant disease, 6 had diabetes mellitus and 6 were treated with corticosteroids.

This study suggests that sputum culture or radiological findings are not sufficient enough to diagnose tuberculosis, especially in compromised host. We emphasize the vital role of treatment for latent tuberculosis for cases with high risk of endogenous reactivation, and it's necessary to make the guideline for the treatment of such latent tuberculosis.