title: Impact of screening with thyroid ultrasonography in myasthenia gravis patients.
abstract: OBJECTIVE
  This study was conducted to screen thyroid abnormality evaluated with ultrasonography (US) in patients with myasthenia gravis (MG) and investigate further when malignancy is suspected.
  
  
  METHODS
  Thyroid screening using US was conducted in 162 patients with MG. In cases where malignancy was suspected, further investigations were performed.
  
  
  RESULTS
  Abnormal US findings were detected in 125 of 162 patients with MG (72 patients with nodules, 74 patients with cysts, 27 patients with diffuse findings such as enlargement, atrophy, a hypoechoic pattern or a heterogenous echoic pattern, and 28 patients with calcification). From among these 125 subjects, 30 patients underwent further examinations such as needle aspiration cytology. As a result, six patients (3.7% of 162 cases) were positive for papillary carcinoma. The size of the carcinoma in three patients was <10 mm, yet the stage of thyroid carcinomas was high (stage III or IVa) in all six cases.
  
  
  CONCLUSIONS
  Our data suggest that the prevalence of thyroid carcinoma in cases of MG may be higher than that of the general population. Furthermore, in patients with MG, there is a possibility that the stage of the carcinoma is higher even when the carcinoma is of a very small size. Patients with MG, when diagnosed, should be advised to undergo US screening of the thyroid because most cases of thyroid carcinoma are highly curable.
authors.affiliation: Department of Clinical Laboratory, Hokkaido Medical Center, Sapporo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Maruyama
authors.forename: N
authors.initials: N
authors.lastname: Minami
authors.forename: M
authors.initials: M
authors.lastname: Niino
authors.forename: N
authors.initials: N
authors.lastname: Fujiki
authors.forename: S
authors.initials: S
authors.lastname: Doi
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Shima
authors.forename: S
authors.initials: S
authors.lastname: Kikuchi
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002291:Carcinoma, Papillary / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D015995:Prevalence; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D013964:Thyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D014463:Ultrasonography; D055815:Young Adult