A rare atypical TSH/GH secreting pituitary adenoma in a 13 year-old boy

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 167-198-Hypothalamus-Pituitary Development & Biology
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-185
Bernardo Dias Pereira*, Tiago Nunes Silva, Henrique Vara Luiz, Andreia Veloza, Ana Catarina Matos, Isabel Manita, Maria Carlos Cordeiro, Luísa Raimundo and Jorge Portugal
Garcia de Orta Hospital, Almada, Portugal
Background: Thyrotrophinomas are very rare in pediatric age. To our knowledge, whe are not aware of any case of a mixed TSH/GH secreting pituitary adenoma formally studied and reported elsewhere in this age range (1).  

Clinical case: A 13.2 years-old (yo) male presented with weight loss, poliphagia, and visual impairment. He had tall stature (182.7 cm, +3.75 SD; target height: 189 cm, +1.54 SD) and normal BMI (17.7 Kg/m2, -0.22 SD), with no thyroid enlargement or signs of orbitopathy. Hormonal surveys revealed elevated TSH (4.63 mU/L, reference value – rv: 0.1-4), fT4 (1.95 ng/dL, rv: 0.93-1.7), fT3 (7.76 pg/mL, rv: 2.57-4.43), tT3 (248 ng/dL, rv: 70-170), a-subunit (6.65 ug/L, rv: <1.6), a-subunit/TSH molar ratio (1.44) and PRL (36 ng/mL, rv: 1.6-20). He had also normal GH (6.49 ng/mL, rv: <10) and IGF-1 (813 ng/mL, rv for age: 183-850), as well as hypocortisolemia (09 am: 1.17 mcg/dL). MRI revealed a 42x35 mm pituitary macroadenoma with optic chiasm compression and bilateral cavernous sinus invasion. Visual field examination showed right temporal hemianopsia and left temporal quadrantanopsia. Transsfenoidal surgery (TSS) was performed and pathological examination revealed GH and PRL positive cells (Ki67: 5%). A 20 mm intrasellar and suprasellar residual tumor and a 20 mm subfrontal component where then ressected by a 2nd TSS and craniotomy, respectively (pathology: GH+, PRL+, Ki67: 10%). Recurrent central hyperthyroidism and elevated IGF-1 (mean of two: 1134 ng/mL) after the first two surgeries led to a TRH test, which showed no TSH response and a GH peak of 7.1 ng/mL (basal: 5.13 ng/mL). A 75 g OGTT indicated also active disease (GH: basal - 5.43 ng/mL; trough – 2.72 ng/mL). After the 3rdsurgery the patient started on octreotide (30 mg, sc, 3-3 weeks) due to uncontrolled gigantism (GH: 23.7 ng/mL; IGF-1 1061 ng/mL, rv: 220-972). On SST analogs central hypothyroidism supervened (on levothyroxine) and a stable residual tumour persists in both cavernous sinus. The patient is now on octreotide plus cabergoline association treatment due to persistently elevated IGF-1 (mean of three: 1076 ng/mL).

Conclusion: We report a rare atypical pituitary adenoma with mixed TSH/GH secretion in a 13 yo boy. Thyrotrophinomas are usually large, invasive macroadenomas (1-3). Due to its rarity in this age range, data are lacking regarding the best therapeutic modalities (1). We also highlight the paramount role of agressive surgery and adjuvant medical therapy in our case.

(1) Kessler M, David R, Pawelczak M, Hanono A, Shah B, Pediatrics 2010; 126: e474-e478. (2) Valdes Socin H, Chanson P Delemer, B, Tabarin A, Rohmer V, Mockel J, Stevenaert A, Beckers A, Eur J Endocrinol. 2003; 148: 433–442. (3) Beck-Peccoz P, Persani L., Endocrinol Metab Clin North Am. 2008; 37: 123–134.

Nothing to Disclose: BDP, TNS, HVL, AV, ACM, IM, MCC, LR, JP

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