Acquired encephalocele attributable to tuberculous osteitis: case report.

OBJECTIVE: There are many forms of calvarial tuberculosis. In this case report, extensive calvarial tuberculosis caused a large cranial defect and occlusion of the sigmoid sinus in a 10-year-old child. This resulted in a transient increase of the intracranial pressure and formation of an acquired encephalocele. CLINICAL PRESENTATION: A 10-year-old boy presented with an acquired, infected encephalocele and features of tuberculous mastoiditis. Computed tomographic and magnetic resonance imaging scans demonstrated evidence of left occipital encephalocele with left mastoiditis, extradural granulations, bone destruction, and complete occlusion of the left sigmoid sinus. INTERVENTION: The encephalocele was surgically excised and combined with left mastoidectomy. Although no mycobacterium had been demonstrated in the excised lesion, the presence of active tuberculous infection in the mastoid led to the conclusion that the bone destruction leading to encephalocele was secondary to the calvarial tuberculosis. The patient received antituberculous treatment with clinical improvement. CONCLUSION: This is the first report of calvarial tuberculosis causing a cranial defect and venous sinus thrombosis and resulting in an acquired encephalocele. Surgical excision combined with medical treatment was curative.