LAUSR

A 13-year-old girl presented to the outpatient department with complaints of double vision for the past 2 months, which was worse while looking down and on either side. She had no history of headache, blurring of vision, eye pain, or excess tears. A cranial nerve examination revealed left lateral rectus palsy with lateral gaze nystagmus on looking to the left. The rest of the neurological and systemic examination revealed no abnormality. Her laboratory investigations and chest X-ray were normal. A CT scan of the brain revealed a lesion at the sphenoclival region with a permeative type of bone destruction with partial sparing of the central area (Fig. 1a– c). A brain MRI showed a predominantly solid lesion involving a body of sphenoid and clivus, with a soft tissue component in the retroclival region and extension into the right cavernous sinus. The lesion was T1 isointense, T2 hypointense, and had a thick ring-enhancing component inferiorly and solid enhancement superiorly (Fig. 1d–f). There was no evidence of adjacent dural enhancement. The radiological possibility of a primary bone tumor such as giant cell tumor was considered. In addition, because of T2 shortening of the inferior necrotic component, tuberculosis was also considered. A trans-sphenoidal biopsy of the lesion was planned for obtaining a tissue diagnosis and the patient was scheduled for surgery. Meanwhile, she was started on antitubercular drug therapy (ATT). Interestingly, the patient improved with ATT and the symptoms gradually subsided over 3 weeks. A repeat MRI after 6 weeks of ATT showed a significant reduction in the size of the lesion as compared to the previous imaging (Fig. 1g–i), confirming the tuberculous etiology. Since the completion of 18 months of ATT therapy, she has been asymptomatic. A repeat MRI of the brain showed complete resolution of the lesion. Tuberculosis has been known to involve almost every region of the central nervous system. However, a primary tuberculoma involving the skull base is rare [1]. Here, we have described a tuberculoma of the clivus mimicking a bony lesion. Common lesions involving the clivus in this age group are giant cell tumor, chordoma, chondrosarcomas, or granulomatous lesions [2]. Lesions with predominantly bony involvement mimicking a neoplasm have been reported few times [1, 3, 4], all of which required a biopsy. Our patient has been medically managed based on imaging and the treatment response. The imaging characteristics of skull base tuberculomas are different from the typical ring-enhancing patterns seen in intraparenchymal tuberculomas, which in most cases can be diagnosed accurately on CT and MRI [5]. In this case, the diffuse enhancement pattern along with permeative bony destruction mimicked a malignant bony le-