Intraparenchymal infiltration of Rathke’s cleft cysts manifesting as severe neurological deficits and hypopituitarism: 2 case reports

BACKGROUND: Rathke’s cleft cysts generally remain asymptomatic throughout life, but a few patients may suffer severe neurological and/or endocrinological deficits. The symptoms include visual disturbances caused by compression of the optic chiasm, and severe endocrinological deficits caused by repeated intracystic hemorrhage or leakage of cyst content. However, no case of Rathke’s cleft cyst has infiltrated into neuroglial tissue with marked cerebral edema. CASE PRESENTATION: Two patients presented with non-infectious re-deterioration of Rathke’s cleft cysts with intraparenchymal infiltration and marked cerebral edema, to ipsilateral hypothalamus in one case and to the bilateral frontal lobes in the other. Both patients were surgically treated by extended transsphenoidal surgery, and showed remarkable improvement with postoperative pulse-dose steroid therapy, including disappearance/shrinkage of abnormal enhanced lesion and cerebral edema on magnetic resonance imaging. Histological examination disclosed significant squamous metaplasia in epithelia and marked infiltration of inflammatory cells into the pituitary gland and neuroglial tissues. Most infiltrated cells were lymphocytes and plasma cells, thought to indicate the involvement of long-term underling inflammatory processes in this phenomenon. CONCLUSION: Long-term subclinical inflammation may be the mechanism of this extraordinary aggressive clinical course. Postoperative steroid administration should be reduced prudently, and careful follow-up imaging is essential in cases of Rathke’s cleft cyst with abnormal histological findings.