A CASE OF TUBERCULOSIS OF THE RIBS MIMICKING METASTATIC BONE DISEASE ON BONE SCINTIGRAPHY

A 56-year-old female with diabetes mellitus presented with fever. The chest roentgenography revealed an extrapulmonary mass on the inside of the right upper thoracic wall, however, there is no abnormality in the lung field. The CT scan demonstrated a destructive osseous change of the second rib associated with an adjacent soft-tissue mass. The bone scintigraphy showed multiple scattered regions of increased uptake in the right 1st, 2nd, and 4th ribs, 9th thoracic vertebra, sternum, and right shoulder joint. Some metastatic bone disease was suspected and operation was carried out. During surgery no lesion was found in the lung. Removal of the right 1st and 2nd ribs and chest wall including tumors were performed. Histopathological examination revealed caseatic necrosis and granuloma with giant cells. A diagnosis of tuberculosis of the ribs was made. Skeletal tuberculosis occurs in approximately 1 per cent of all patients with tuberculosis. Tuberculosis of ribs is rare because ribs are involved in about 5 per cent of the cases of skeletal tuberculosis. Destructive osseous changes associated with adjacent soft-tissue masses on CT scan and multiple scattered increased uptake areas on bone scintigraphy can be seen with osseous tuberculosis besides metastatic bone disease.