Isolated iliac bone tuberculosis : a case report

Background: Isolated iliac bone tuberculosis is not easy for diagnosis as it can mimic many other conditions. The presentation of our case of isolated iliac bone tuberculosis with special emphasis to imaging findings is justified, by its rarity and not uncommon delay in diagnosis and therapy of such cases. Case Report: A case of isolated iliac bone tuberculosis, initially presented with low back pain and swelling, was unsuccessfully treated for three months before final diagnosis was established. Plain radiography revealed only slight sclerosis of the iliac side of the right sacro-iliac joint. MRI provided more precise and detailed information regarding the site, size and nature of the bony and soft tissue components of the lesion. The bony lesion showed low T1, high T2 signal and marginal enhancement on fat suppressed T1 post-gadolinium images. The soft tissue components also showed post-gadolinium enhancement and abscesses formation. CT scan confirmed the bony lytic lesion and provided guidance for biopsy. Histology confirmed tuberculous nature of the lesion. Conclusions: Imaging presentation of tuberculous osteomyelitis is nonspecific and may mimic many inflammatory and neoplastic conditions. Correlation with the patient's history, immune status, ethnicity, social environment is necessary in narrowing differential diagnosis. This means that iliac tuberculosis, despite its rarity, should be considered as one of diagnostic possibilities, especially in the patients from endemic areas. However, definitive diagnosis is best established with bone needle biopsy.