Age / Sex : 25 / F

Age / Sex : 25/F

Tuberculous osteomyelitis

Discussion

Findings:

Right tibia lateral radiography shows ovoid osteolytic lesion with indistinct margin and minimal periosteal reaction at the meta-diaphyseal junction.

Sagittal T2WI shows an osteolyic defect with peripheral high SI and central low SI at the meta-diaphyseal junction. Periosteal reaction is combined at pretibial region. There is another osteolytic lesion with same nature at the epiphysis, which is not definite on plain radiography. And diffuse inhomogenous intermediate bone marrow SI can be also seen in the tibia. After contrast enhancement, two masses shows thick peripheral enhancement.

Differential Diagnosis:

Brodie’s abscesses, bone metastases.

Diagnosis:  

Tuberculous osteomyelitis

Discussion:

 The femur, the tibia, and the small bones of the hands and feet are most commonly involved by tuberculous osteomyelitis. Typically, the metaphyses are affected. Radiographic findings include osteopenia, osteolytic foci with poorly defined edges, and varying amounts of sclerosis. Also, CT and MR imaging demonstrate the extent of the active infection and its complications.

One specific type of tuberculous osteomyelitis is cystic tuberculosis. At radiography, the lesions are radiolucent, well defined, and round or oval and demonstrate variable amounts of sclerosis. The radiographic characteristics of cystic tuberculosis resemble those of eosinophilic granuloma, sarcoidosis, cystic angiomatosis, plasma cell myeloma, chordoma, fungal infections, and metastases.

Tuberculous involvement of the short, tubular bones of the hands and feet is termed tuberculous dactylitis. This form of tuberculosis is especially frequent in children. Fusiform soft-tissue swelling and periostitis are the most common radiographic findings. As underlying bone is destroyed, a cystlike cavity forms and the remaining bone appears to be ballooned out. This appearance is termed spina ventosa (“wind-filled sail”).

Tuberculous osteomyelitis can be mimicked by pyogenic or fungal infections. A helpful feature in distinguishing tuberculous from pyogenic infection is that transphyseal spread occurs in the former; however, fungal infections can also extend across the physis.

References:

1. Resnick D: Diagnosis of bone and joint disorders, Ed. 3. Philadelphia, WB Saunders, 1988

2. Engin G, Acunaş B, Acunaş G, Tunaci M. Imaging of extrapulmonary tuberculosis. Radiographics 2000; 20:471-488