We reported a rare case of pleomorphic TSH-producing
pituitary adenoma with calcification and reviewed the literature. A 25-year-old female was admitted to our hospital with a complaint of anterior neck swelling. An endocrinological examination demonstrated elevated serum levels of free
triiodothyronine (FT3: 5.6 pg/ml), free
thyroxin (FT4: 2.2 ng/dl), TSH (5.85 microIU/ml), and TSH a-subunit (5.9 ng/ml), whereas a physical examination revealed no
goiter. CT scan showed a suprasellar isodensity mass with dense calcification. Contrast-enhanced T1-weighted images revealed a less enhancing
tumor extending from the left upper portion of pituitary fossa into suprasellar cistern. The patient underwent gross total removal of the
tumor via the right pterional approach. Microscopically, medium-sized to enlarged
tumor cells with marked pleomorphism and prominent calcification were observed. The
tumor cells displayed positive reaction for
TSH (beta-subunit). The MIB-1 index averaged 2.9%. The histological diagnosis was a pleomorphic TSH-producing
pituitary adenoma. Postoperatively, the serum levels of FT3, FT4, TSH, and
TSH alpha-subunit decreased to normal range. Follow-up MR images showed no evidence of recurrent
tumor 3 years after the resection. All of six patients with densely calcified TSH-producing
pituitary adenoma, previously reported in the literature, remained well without
tumor recurrence. We suggest that this type of TSH-producing
pituitary adenoma may be associated with favorable prognosis despite histologically pleomorphic appearance.