Spontaneous resolution of a cyst of the septum pellucidum

Septum pellucidum cysts are rare clinical findings. Although their optimal treatment remains controversial, large cysts causing hydrocephalus or neural compression should be treated surgically. However, spontaneous resolution can also occur. Herein, the authors present a case of a 38-year-old woman suffering from intermittent headache associated with an expanding cyst of the septum pellucidum. No surgical intervention was performed as hydrocephalus was not observed. After 16 months follow-up, both her symptom and the cyst (assessed by magnetic resonance imaging) had disappeared. To the best of the authors' knowledge, this is only the third reported case of spontaneous resolution of a septum pellucidum cyst. This case suggests that a symptomatic septum pellucidum cyst is not an absolute indication for surgical treatment. A conservative approach with close follow-up with computerized tomography or magnetic resonance imaging is strongly recommended unless the cyst causes obvious hydrocephalus or progressive neurological deterioration.