title: Non-Alpine thyroid angiosarcoma.
abstract: BACKGROUND
  Angiosarcoma is a very rare entity of soft tissue neoplasm with an aggressive and destructive biological behavior. Thyroid angiosarcoma is usually reported in Alpine regions, with only exceptionally rare cases arising in non-mountainous areas. In the Alpine regions it constitutes 2-10% of all malignant thyroid tumors.
  
  
  METHODS
  We report a case of a thyroid non-Alpine angiosarcoma in a 71-year-old female with a 10 years old multinodular goiter. The cervical mass underwent rapid growth in the last year, and she was referred for surgical treatment. A 15cm mass was found on the right side of the neck invading adjacent tissues and displacing the trachea without obvious invasion of this organ. Fine needle aspiration cytology showed "carcinoma". Lung metastasis were present. Although difficult, total thyroidectomy was possible with resection of an esophageal implant. Post-operatively, she had respiratory failure that eventually recovered, but, on 39th post-operative day, she died of violent hemoptysis, probably due to invasion by mediastinal metastasis.
  
  
  CONCLUSIONS
  A clear distinction between angiosarcoma and anaplastic carcinoma of the thyroid is considerably difficult, despite treatments and prognosis are practically the same. However, in recent years, a thyroid malignancy exhibiting phenotypical features of endothelial differentiation was described. Keratin positivity cannot be reported as necessarily indicative of epithelial differentiation.
  
  
  CONCLUSIONS
  Optimal treatment for thyroid angiosarcoma remains unclear, not only because the prognosis is poor, despite multimodal therapeutic efforts, but also because it is a very rare entity.
authors.affiliation: Unidade Local de Saúde de Matosinhos, Matosinhos, Portugal. Electronic address: pedrogouveia@mac.com.
authors.forename: Pedro
authors.initials: P
authors.lastname: Gouveia
authors.forename: Catarina
authors.initials: C
authors.lastname: Silva
authors.forename: Fátima
authors.initials: F
authors.lastname: Magalhães
authors.forename: Claúdia
authors.initials: C
authors.lastname: Santos
authors.forename: Emanuel
authors.initials: E
authors.lastname: Guerreiro
authors.forename: Filipe
authors.initials: F
authors.lastname: Santos
authors.forename: Teixeira
authors.initials: T
authors.lastname: Gomes