Spontaneous resolution of residual pituitary adenoma. Case report.

A 34-year-old man presented with progressive diminution of vision in the left eye for 7 years. He had suffered left hemicranial headache associated with left retro-orbital pain and diplopia for 3 months. Magnetic resonance (MR) imaging revealed a pituitary tumor located in the sella and extending into the right cavernous sinus. After transsphenoidal surgery, the vision improved drastically but the diplopia persisted. Postoperative MR imaging showed residual tumor in the right cavernous sinus. Follow-up examination after 3 years showed the diplopia had completely recovered and the residual tumor in the cavernous sinus had disappeared. Spontaneous resolution of a large intracavernous sinus residue of a pituitary adenoma may occur due to tumor necrosis.