A long-term follow-up study of eighteen patients with thyrotropin-secreting pituitary adenomas

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 88-111-Cushing's Disease & Non-Functioning Hypothalamus-Pituitary Tumors
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-100
Nad├Ęge C van Varsseveld*1, Peter H Bisschop2, Nienke R. Biermasz3, Alberto M. Pereira4, Eric Fliers2 and Madeleine L. Drent1
1VU University Medical Center, Amsterdam, Netherlands, 2Academic Medical Center, Amsterdam, Netherlands, 3Leiden University Medical Center, Leiden, Netherlands, 4Leiden University Medical Center, The Netherlands
Background: Thyrotropin (TSH)-secreting pituitary adenomas are a rare cause of thyrotoxicosis. First-line therapy for these tumors is neurosurgery, although medical therapy with somatostatin analogs (SSAs) is increasingly used for this indication.

Design: We retrospectively reviewed the data of patients with a TSH-secreting pituitary adenoma (n=18, 67% males) followed between 1989 and 2011 (median follow-up 7 years, range 1-21) in three academic medical centers in the Netherlands, focusing on the role of SSA treatment.

Methods: Patient records were reviewed for clinical, biochemical, imaging, pathological and treatment characteristics.

Results: At initial evaluation, biochemical hyperthyroidism with non-suppressed TSH concentrations was detected in 94% of the patients. The majority of patients (72%) had a macroadenoma with extrasellar extension. Fourteen patients underwent surgery, resulting in postoperative euthyroidism in six patients (43%). Recurrence of hyperthyroidism developed in 3 of them after 5, 24, and 32 months respectively. Adjuvant radiotherapy (n=2) did not induce remission. Three patients received SSA therapy exclusively, resulting in cure in one of them. During long-term follow-up, 72% of all patients required medical therapy (mostly SSA treatment). Euthyroidism was achieved in all but one patient, who refused all treatments.

Conclusions: Our results demonstrate that patients with TSH-secreting pituitary adenomas, who often present with large macroadenomas with extrasellar extension, have an excellent response to SSA therapy. Because the results of surgery and radiotherapy are disappointing, primary medical therapy can be considered in every patient, especially in those harboring large adenomas with parasellar extension.

Nothing to Disclose: NCV, PHB, NRB, AMP, EF, MLD

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm