Calvarial tuberculosis in a paediatric patient: a diagnosis not to forget

We report the case of a 10-year-old boy that presented with a palpable, painless, frontal lesion. Laboratory assessments were unremarkable and the patient was asymptomatic. Initial investigation, with a skull radiograph and unenhanced CT scan, showed a lytic midline frontal lesion involving the inner and outer tables of the skull and a large subgaleal hypodense component. MRI further depicted communication with the epidural space and contact with the superior sagittal sinus (SSS). Subsequent evaluation by Doppler ultrasound and MR angiography excluded a sinus pericranii and showed normal patency of the SSS. Surgical biopsy revealed chronic granulomatous inflammation; PCR was positive for Mycobacterium sp. One year after surgical resection and antitubercular therapy, there are no signs of recurrence. Primary calvarial involvement by tuberculosis is rare, even in developing countries. Familiarity with the expected clinical and imaging features is required to avoid diagnostic delay.