A612 | Journal of the Endocrine Society | doi: 10.1210/jendso/bvab048 A612 J Endocrine Soc, Volume 5, Issue Supplement_1, April-May 2021 Clinical Case: A 52-year-old woman with a history of multinodular goiter was incidentally found to have a 2.2 x 1.8 x 2.1 cm pituitary macroadenoma with suprasellar extension, mass effect on the optic chiasm, and left cav- ernous sinus involvement when she presented with chest pain, palpitations, headache, and left-sided numbness and weakness. Laboratory results showed high FT4/T4/ T3 with inappropriately high TSH, elevated α-subunit, and low cortisol with low-normal ACTH highly suggestive of TSH-oma with concurrent secondary adrenal insuff- ciency. An ophthalmology exam revealed a left superior temporal defect. The patient was treated with atenolol, prednisone, and octreotide two weeks before surgery with symptomatic improvement and near-normalization of FT4. Following an uncomplicated transsphenoidal resec- tion, FT4 normalized within one week. At her one-month follow-up, both TSH and FT4 were normal, and her sec- ondary adrenal insuffciency had resolved. Her visual feld defect also recovered. Laboratory Results: TSH 5.35 (normal range 0.40- 4.60 μU/mL), FT4 3.0 (0.8-1.7 ng/dL), T4 18.1 (5.0-12.0 μg/ dL), T3 235 (80-200 ng/dL), ACTH 10 (6-50 pg/mL), cor- tisol 4.5 (5.0-25.0 μg/dL), α-subunit 8.0 (0.1-1.5 ng/mL); after 2 weeks on SQ octreotide 50mg q12h: TSH 1.93 (0.30- 4.20 μU/mL), FT4 1.7 (0.6-1.5 ng/dL); 1 month post-op: TSH 1.53 (0.30-4.20 μU/mL), FT4 0.8 (0.6-1.5 ng/dL), ACTH 12 (7.2-63 pg/mL), cortisol 6.9 (4.0-20.0 μg/dL) Conclusion: Since the frst reported case of TSH-oma in 1960, the diagnostic and therapeutic management of these rare pituitary adenomas have evolved due to the emer- gence of ultrasensitive TSH assays, advanced imaging and surgical techniques, and somatostatin analogs. However, to this day, most TSH-omas are still diagnosed at the stage of invasive macroadenomas, when successful surgical re- section becomes more diffcult. Hence, up to two-thirds of patients may require adjuvant therapy with medication or radiation. As evidenced in our patient, who achieved a near-euthyroid state within just two weeks of starting low dose octreotide, somatostatin analogs are highly effective in controlling hyperthyroidism and have solidifed their place in the therapeutic management of TSH-omas. This case highlights the success of a multimodal approach to the treatment of TSH-omas. Neuroendocrinology and Pituitary NEUROENDOCRINOLOGY AND PITUITARY CASE REPORTS Successful Pregnancies in an Acromegalic Woman After Non-Radical Pituitary Adenomectomy for Somatoprolactinoma Anna Catarina Gatzk Arruda, MD, Giovana Outuki, MD, Marcos Antonio Dias, MD, Alexandre Jose Faria Carrilho, MD, PhD, Tania Longo Mazzuco, MD, PhD. Universidade Estadual de Londrina-UEL, Londrina PR, Brazil. Background: Pregnancy is unusual in patients with acro- megaly due to somatotropinomas or somatoprolactinomas. Fertility is impaired because of hormonal hypersecretion, pituitary damage by tumor compression or both. Managing somatoprolactinomas and fertility issues are often challenging. Clinical Case: A 20-year woman with primary amenorrhea and headache was diagnosed with hypogonadotrophic hy- pogonadism secondary to hyperprolactinemia (2500 µg/L, n<23 µg/L). No other abnormalities were found on the pi- tuitary function screening tests. MRI revealed an intra and suprasellar adenoma (2.5x1.8x1.8 cm) with optic chiasm compression. The onset of menses occurred after 11 months under dopaminergic treatment, and tumor size diminished (1.9x1.5x1.5 cm), bringing on optic chiasm decompres- sion. She remained under dopamine agonist treatment for 6 years, when she realized extremities enlargement and height increase by 3 cm. Acromegaly was confrmed by blood levels of IGF-1 (3.37xULN), GH (8 µg/L, n<8 µg/L), and GH nadir (4.3 µg/L, n<1 µg/L) during OGTT. Then, octreotide LAR was added to cabergoline treatment while waiting for elective surgical treatment. She underwent to transsphenoidal endonasal neurosurgical microscopy approach guided by neuronavigation, with the removal of a large portion of tumor. However, it was not possible to extract the part of invasive adenoma close to right ca- rotid artery due to the risk of vascular and intracavernous cranial nerves injury. Immunohistochemistry analysis of the adenoma was positive only for GH cells with low Ki67 index (<1%). Due to the poor biochemical control (unsuppressed post-OGTT GH, IGF-1 1.66xULN and PRL 301 µg/L) and the presence of a small stable tumor residue, treatment with cabergoline and somatostatin analogues was maintained (3-year octreotide LAR, transitioned to lanreotide in an attempt to achieve a better biochemical re- sponse). After 14 years of the initial diagnosis and 5 years post-surgery, the patient expressed the desire to get preg- nant and all medications in use were suspended. In the fol- lowing 3 years, she had two uneventful gestation without complications or worsen of acromegaly; she only breastfed for few months after her frst pregnancy. The second one was a twin pregnancy. After one year, the MRI revealed no increase of tumor mass (1.0x0.3x1.0 cm), and PRL levels withing normal range, IGF-1 slightly elevated, but GH not suppressed by OGTT. Cabergoline was reintroduced and the biochemical control of acromegaly was achieved. Conclusion: We reported the very unusual sponta- neous conception and normal course of pregnancies in a woman with acromegaly, who was submitted to successful transsphenoidal neurosurgical microscopy approach in which large part of the tumor was removed and the normal pituitary tissue was preserved, allowing fertility restoration. Neuroendocrinology and Pituitary NEUROENDOCRINOLOGY AND PITUITARY CASE REPORTS Successful Treatment of Myxedema Coma Using Liothyronine in the Setting of Adrenal Crisis Omar Elghawy, BS 1 , Alexander C. Hafey, BS 1 , Christopher Rolland McCartney, MD 1 , Jeremy R. Steinman, MD 2 . 1 University of Virginia School of Medicine, Charlottesville, VA, USA, 2 University of Virginia Health System, Charlottesville, VA, USA. Background: Myxedema coma (MC) represents severe decompensated hypothyroidism and is associated with Downloaded from https://academic.oup.com/jes/article/5/Supplement_1/A612/6241876 by guest on 24 August 2022