[A case of sellar T cell type malignant lymphoma]

A case of primary T cell type malignant lymphoma of the sellar region was reported. This 53-year-old male was admitted to our neurosurgical service because of slowly progressive occipitalgia and diplopia over the previous 5 months. On admission neurological examination revealed a slight limitation of the lateral movement of the left eye. Endocrinological examination showed no abnormalities. Despite a mild neurological deficit, a CT scan revealed an extensive bony destruction around the sellar region including the dorsum sellae, the bilateral petrous apices, and the upper two thirds of the clivus. Magnetic resonance imaging (MRI) disclosed that the tumor was slightly hypointense on T1-weighted image, isointense on T2-weighted image, and faintly and homogeneously enhanced after administration of Gd-DTPA. Since the tumor was enhanced faintly on MRI, it was diagnosed as an invasive pituitary adenoma, but it was thought that chordoma and germinoma should be considered. The patient underwent a transsphenoidal surgery. A firm, grayish and avascular tumor was partially removed. The histopathological examination using monoclonal surface marker of the specimen revealed the tumor was stained with UCHL-1 and CD3 antibodies directed against T cells, and diagnosed as T cell type malignant lymphoma of the sellar region (diffuse, large cell type; LSG). Postoperatively he received radiation therapy. His symptoms much improved and no regrowth of the residual tumor has been found in follow-up studies to the present. Primary malignant lymphomas very rarely occur in the skull base. As far as we are aware, this is the only second case of primary T-cell lymphoma in the sellar region reported so far in the medical literature. Although preoperative diagnosis is extremely difficult because of a paucity of data, malignant lymphomas should be kept in mind in the differential diagnosis of sellar tumors, especially if neuroimaging studies show an extensive bony destruction in the skull base.