title: Anaplastic transformation of papillary thyroid carcinoma in multiple lung metastases presenting with a malignant pleural effusion: a case report.
abstract: BACKGROUND
  Anaplastic transformation of well-differentiated papillary thyroid carcinoma at distant metastasis sites is rare. To the best of our knowledge, this is the first report of an autopsy case of anaplastic transformation of papillary thyroid carcinoma in multiple lung metastases presenting with a malignant pleural effusion.
  
  
  METHODS
  We report an autopsy case of a 61-year-old Japanese man with anaplastic transformation of papillary thyroid carcinoma with multiple lung metastases presenting with a malignant pleural effusion, which was difficult to diagnose by cytological examination before the autopsy. He presented with a 1-month history of progressive dyspnea, and examination of the left pleural effusion revealed a bloody exudate with an increase in thyroglobulin; however, malignant cells in the pleural fluid were negative for thyroglobulin.
  
  
  CONCLUSIONS
  It is important to be aware that anaplastic transformation of differentiated thyroid carcinoma could develop in lung metastases and could be a cause of a malignant pleural effusion.
authors.forename: Tomoe
authors.initials: T
authors.lastname: Abe
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan. suzumasa@med.hokudai.ac.jp.
authors.forename: Masaru
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kaoruko
authors.initials: K
authors.lastname: Shimizu
authors.forename: Naofumi
authors.initials: N
authors.lastname: Shinagawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Oizumi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuno
authors.forename: Masaya
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Mishie
authors.initials: M
authors.lastname: Tanino
authors.forename: Shinya
authors.initials: S
authors.lastname: Tanaka
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D000230:Adenocarcinoma / Q000150:complications* / Q000556:secondary*; D001344:Autopsy; D002277:Carcinoma / Q000473:pathology*; D002291:Carcinoma, Papillary; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000150:complications*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology*