Sellar abscess associated with tuberculous osteomyelitis of the skull: MR findings.

A 3-year-old boy had had a soft-tissue swelling in the left temporal region for 6 months. The swelling was gradually increasing in size and had been associated with progressive diminution of vision for 4 months. Physical examination revealed perception of light only in the right eye and complete loss of vision in the left eye. The temporal swelling was cystic, nontender, and associated with formation of a sinus. Skull radiographs showed multiple osteolytic lesions in the left temporal bone. CT scans showed complete destruction of both tables of the left temporal bone and osteolysis of posterior ethmoid and sphenoid bone. In addition , a sellar hypointense, irregular mass was seen. MR showed an area of complete destruction of the left temporal bone with communication between extradural space and subcutaneous collection . The extradural collection extended along the left temporal lobe. It showed low-intensity central signal and a peripheral rim isointense with brain parenchyma on T1 -weighted images and mixed highand low-intensity signals on T2-weighted images (Fig. 1 ). In addition , a large intrasellar mass with suprasellar extension was seen; it was isointense on T1-weighted images and of mixed intensity on T2-weighted images. Surgical exploration of the left temporal area showed extradural , thick pus with granulation tissue. The results of a bone biopsy from its osteolytic edge and the extradural granulation tissue were consistent with tuberculous osteomyelitis and caseous tuberculous granulation tissue. The child was put on specific antituberculous chemotherapy and showed marked clinical improvement. Repeat MR after 2112 months of specific treatment showed a reduction in the size of the extradural collection and the sellar lesion.