title: Toxic thyroid adenoma presenting as hypokalemic periodic paralysis.
abstract: Toxic thyroid adenoma presenting as hypokalemic periodic paralysis is extraordinarily rare. We describe a 26-year-old Japanese man who suffered from acute and painful muscle weakness of extremity in the morning. Physical examination showed a left anterior neck mass and laboratory tests revealed hypokalemia during his paralysis, and thyrotoxicosis. Neck sonogram showed a solitary nodule in the left lobe of the thyroid. Thyroid scintigraphy revealed a hot nodule of the tumor region with suppressed uptake in the other thyroid area. The tumor was surgically removed and his paralytic attack ceased. No somatic mutation of TSH receptor was found in his thyroid adenoma and no known genetic mutations of ionic channel genes, such as calcium (CACN1S), sodium (SCN4A) and potassium (KCNE3), were found. Although thyrotoxic periodic paralysis is usually accompanied with Graves' disease, thyrotoxicosis of other conditions including Plummer's disease should be considered.
authors.affiliation: Clinical Research Institute, Division of Endocrinology and Metabolism, Kyoto Medical Center, National Hospital Organization, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tagami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Usui
authors.forename: Akira
authors.initials: A
authors.lastname: Shimatsu
authors.forename: Mitsuhide
authors.initials: M
authors.lastname: Naruse
mesh_terms: D000236:Adenoma / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D000328:Adult; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D006801:Humans; D020514:Hypokalemic Periodic Paralysis / Q000175:diagnosis*; D007473:Ion Channels / Q000235:genetics; D008297:Male; D011989:Receptors, Thyrotropin / Q000235:genetics; D013964:Thyroid Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D013971:Thyrotoxicosis / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics
chemical_list: D007473:Ion Channels; D011989:Receptors, Thyrotropin