title: Amelanotic malignant melanoma arising in an ovarian cystic teratoma: a case report.
abstract: BACKGROUND
  Malignant melanoma arising in a cystic teratoma is extremely rare. We report the clinicopathologic and cytopathologic features of an amelanotic malignant melanoma arising in an ovarian cystic teratoma.
  
  
  METHODS
  A 55-year-old woman presented with an asymptomatic right ovarian mass, showing features of cystic teratoma according to preoperative computed tomography and magnetic resonance imaging. The resected teratoma was suspected to include a nonepithelial malignancy in a touch preparation from a solid component. The tumor showed immunoreactivity for Melan-A, S-100 and HMB-45 in the absence of melanin granules, which established the diagnosis of amelanotic malignant melanoma arising in an ovarian cystic teratoma.
  
  
  CONCLUSIONS
  Cytopathologic findings from touch preparations and immunohistochemical staining are useful for the diagnosis of amelanotic malignant melanoma arising in an ovarian cystic teratoma.
authors.affiliation: Department of Obstetrics and Gynecology, Kinki University School of Medicine, Osaka, Japan. watanabe@med.kindai.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.forename: H
authors.initials: H
authors.lastname: Ueda
authors.forename: H
authors.initials: H
authors.lastname: Nakajima
authors.forename: R
authors.initials: R
authors.lastname: Minoura
authors.forename: H
authors.initials: H
authors.lastname: Hoshiai
authors.forename: K
authors.initials: K
authors.lastname: Noda
mesh_terms: D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D018328:Melanoma, Amelanotic / Q000378:metabolism / Q000473:pathology / Q000556:secondary*; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*; D013330:Struma Ovarii / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D013724:Teratoma / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods