title: Chondromatous differentiation in clear cell carcinoma of the ovary: a rare finding challenging the differential diagnosis.
abstract: OBJECTIVE
  Ovarian surface epithelial tumors rarely have heterologous elements including bone or cartilage that may appear histologically benign or malignant. There are a few case reports in the literature of ovarian tumors containing chondromatous areas.
  
  
  METHODS
  We report a clear cell carcinoma of the bilateral ovary showing chondromatous differentiation in a 56-year-old woman. Histopathologic study of the specimen showed clear cell carcinoma with many small foci of chondromatous differentiation. Immunohistochemical studies demonstrated positivity for S-100 confirming the diagnosis. The patient was alive with disease on chemotherapy for 16 months.
  
  
  CONCLUSIONS
  A rare case of benign appearing chondromatous differentiation in an ovarian clear cell carcinoma of the ovary is described, and the significance of this finding is discussed.
authors.affiliation: Department of Pathology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Metin
authors.initials: M
authors.lastname: Akbulut
authors.forename: Osman
authors.initials: O
authors.lastname: Zekioglu
authors.forename: Mustafa Cosan
authors.initials: MC
authors.lastname: Terek
authors.forename: Necmettin
authors.initials: N
authors.lastname: Ozdemir
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D002454:Cell Differentiation / Q000502:physiology; D002812:Chondroma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery