RESUMO
PURPOSE: To demonstrate and evaluate the value of MRI findings of the TSH(Thyroid-Stimulating Hormone, TSH, Thyrotropin)-secreting pituitary adenoma. MATERIALS AND METHODS: The authors reviewed retrospectively the MR images of 4 patients with TSH-secreting pituiatary adenoma. Evaluation of the anatomical location, signal characteristics, enhancement patterns, size, shape and circunferential changes were made. RESULTS: No characteristic common MR findings in size, shape, signal intensity, and circumferential changes of TSH-secreting pituiatary adenoma waere observed among 4 cases(size; 5x7 mm to 10x11 mm, shape;ovoid to round, signal intensity;high in 1 case on T1 and T2WI, isosignal intensity in the other 3 cases, circumferential change; stalk deviation in 1 case, no stalk deviation in 3 cases). But, the tumors were centrally located at the anterior pituitary gland and showed relatively homogeneous signal intensity on MR images of all 4 patients. CONCLUSION: We conclude that centrally-located mass at the anterior pituitary gland with homogeneous signal intensity on MR image may be suggestive of the TSH-secreting pituitary adenoma, although the MR findings are not specific for the disease.