Thyrotropin-secreting pituitary adenoma in an adolescent boy: challenges in management.

Thyrotropinomas tend to be aggressive, invasive tumors that are difficult to resect because of their marked fibrosis and their proximity to vital structures such as the optic chiasm. The latter characteristic also limits the use of radiation therapy. In the few cases reported of children younger than 18 years whose thyrotropinomas were treated surgically, the results were disappointing. We present here the case of a 16-year-old boy with a thyrotropin-secreting pituitary macroadenoma who underwent partial resection via a transsphenoidal approach and was left with significant residual tumor and continued hyperthyroidism. He subsequently received 4 years of long-acting release somatostatin therapy, during which he has remained euthyroid without requiring antithyroid medication. To our knowledge, this is thus far the longest duration of somatostatin therapy in the pediatric age group. This regimen also achieved a decrease in compression of the optic nerve and prevented further tumor growth. We review here the current literature on somatostatin analog treatment including molecular mechanisms and promising new treatment modalities, such as the heterodimerization of dopamine and somatostatin receptors. We conclude that this has been a useful adjuvant treatment for our adolescent patient.

Antenatal treatment of fetal goiter: a therapeutic challenge.

OBJECTIVE: Pre-natal ultrasonography presents an opportunity for in-utero therapy of a fetal goiter. Because of the morbidity associated with a large goiter and the risks of repeated intra-amniotic injections, controversy arose about the precise indications of this mode of treatment. We describe our observations in treating a 22-week-old fetus with a large goiter because of dyshormogenesis, monitored with serial 3D high frequency, high resolution ultrasonography and amniotic hormonal measurements. Fetal hypothyroidism was confirmed by cordocentesis and amniotic hormone levels. After assessment of relevant risk factors and the criteria for in-utero intervention, including goiter volume, amniotic fluid index, polyhydramnios and tracheal compression, we determined that hormonal therapy was warranted. Levothyroxine was injected every 7-10 days, and its efficacy monitored by ultrasound changes and amniotic hormone sampling. RESULTS: Reduction in goiter volume restored normal neck flexion relieving the pressure on the trachea, polyhydramnios was prevented and amniotic hormone levels were normalised. The infant was euthyroid at birth, however, by age 4 days hypothyroidism was diagnosed, and treatment with l-thyroxine started. CONCLUSION: Advances in fetal ultrasonography permit judicious therapy of an enlarging goiter in a hypothyroid fetus, which may contribute to enhancing cognitive development. We discuss the value of amniotic hormone sampling, the objectives and risks of in-utero intervention in the light of recent literature and our own observations.