Giant supratentorial enterogenous cyst: report of a case, literature review, and discussion of pathogenesis.

OBJECTIVE AND IMPORTANCE

To describe a histologically well-documented adult case of a giant supratentorial enterogenous cyst (EC). Fewer than 15 cases of supratentorial ECs are on record: 8 associated with the brain hemispheres or the overlying meninges, 4 with the sellar region, and 2 with the optic nerve.

CLINICAL PRESENTATION

A 31-year-old woman complained of long-standing mild left brachial and crural motor deficit precipitated by headache and signs of intracranial hypertension. Magnetic resonance imaging revealed a huge cyst overlying the frontoparietal brain.

INTERVENTION

Symptoms were relieved by evacuation of the cyst content by means of a Rickam's reservoir, and the lesion was subsequently removed in toto. Histological and immunohistochemical examination of the cyst wall clearly established the enterogenous nature of its epithelium. Follow-up for up to 2 years after intervention showed no sign of recurrence, and symptoms, including treatment-resistant seizures in the postoperative period, have entirely subsided.

CONCLUSION

Supratentorial ECs, distinctly rare in adult patients, may in some cases present as giant lesions. Total removal seems to be curative once careful examination has eliminated the possibility of a metastasis from an unknown primary. A correct histological diagnosis is important because, in contrast to other benign cysts of similar location and size, ECs may be prone to intraoperative dissemination.