A Case of TSH Secreting Pituitary Adenoma with Calcification

A 42-year-old man was incidentally found to have swelling of the thyroid gland during a medical examination. On his endocrinological studies, the level of serum free T3, free T4 and TSH were elevated. TSH reacted to neither TRH nor free T3. MRI revealed an intra and supra-sellar enhanced tumor and plain CT showed that the tumor was partly surrounded by capsular calcification. Surgery was performed twice at the 3-weeks interval by the transsphenoidal route, and the tumor was totally removed except for the capsular calcification. Immunohistochemical examination showed positive staining for TSH, and FSH and GH at part. Pathological diagnosis was TSH secreting pituitary adenoma. TSH secreting pituitary adenomas with calcification are rare, and there have been only 6 cases reported including ours. We discuss the clinical charactaristics and surgical strategy of this particular adenoma.