A case of hyperthyroidism due to pituitary resistance to thyroid hormone.
A fifteen-year-old male was admitted to our hospital because his thyroid function showed a lack of TSH suppression in the face of elevated thyroid hormone. This patient complained of heat intolerance, palpitation and hand tremor. Peripheral indices of thyroid hormone action indicated a hypermetabolic state. Serum TSH did not respond sufficiently to TRH stimulation, suggesting TSH-secreting pituitary adenoma. However, sellar CT scan and MRI images did not demonstrate any pituitary adenoma. Moreover, the serum TSH alpha-subunit concentration was not high and serum TSH was partially suppressed by the administration of T3. Furthermore, the results of single stranded conformation polymorphism (SSCP) suggested the existence of mutation(s) in the exon 7 of T3 receptor beta (TR beta) gene of this patient. These findings support the diagnosis of pituitary resistance to thyroid hormone.
Department of Laboratory Medicine, Osaka University Medical School, Suita, Japan.
Y
Y
Hidaka
H
H
Tada
T
T
Kashiwai
S
S
Sasaki
S
S
Andoh
H
H
Nakamura
N
N
Amino
D000236:Adenoma / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D000293:Adolescent; D004351:Drug Resistance; D018776:Genes, erbA / Q000235:genetics; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy / Q000209:etiology* / Q000378:metabolism; D008297:Male; D010911:Pituitary Neoplasms / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D017354:Point Mutation; D013963:Thyroid Hormones / Q000627:therapeutic use*; D013972:Thyrotropin / Q000097:blood*
D013963:Thyroid Hormones; D013972:Thyrotropin