Intracranial lipoma: an incidental finding and a rare cause of secondary headache.

Aim of the study: Expand the differential diagnosis of secondary headache to include rare intracranial tumours, detected incidentally on brain imaging. Intracranial lipomas are rare congenital malformations, and are usually pericallosal asymptomatic midline lesions. However, some cases present with headache and seizures. Symptomatic intracranial lipomas are very rare and often detected incidentally on brain imaging.

Methods: We present a 52-year-old woman referred to our tertiary centre with a history of hypothyroidism presented with headache for 2 years. She had generalised body pains for six months. Her headache was persistent despite being on medications. Physical and neurological examination was unremarkable. Her visual acuity and fundus examination were normal.

Results: Her brain imaging revealed a lesion over the corpus callosum and in the interhemispheric fissure with signal attenuation on the fat suppression sequence, features suggestive of curvilinear pericallosal lipoma. Symptomatic treatment with analgesics and anti-inflammatory agents were slightly effective. It is debatable whether tumour removal is required, as the risks of surgical intervention far outweigh the potential benefits.

Conclusion: Corpus callosal lipoma is a rare and unrecognised cause of secondary headache. It should be suspected in patients with an atypical headache without papilledema and who are unresponsive to analgesics. This may be the only presenting feature of intracranial lipomas rendering it even more difficult to suspect and diagnose, thus emphasising the importance of evaluating secondary headaches. Diagnosis is important because long-term follow-up may be required if patients develop new focal deficits, which may necessitate surgical intervention.