title: Clear cell carcinoma of the base of the tongue: case report and literature review.
abstract: OBJECTIVE
  Clear cell carcinoma (CCC) is a rare, low-grade malignant neoplasm of minor salivary glands. Clear cell carcinoma is composed of monomorphic clear cells that contain glycogen within a hyalinized stroma. The microscopic diagnosis can be challenging, and the treatment strategy has not been established.
  
  
  METHODS
  We report a case of a 56-year-old woman with CCC in the base of the tongue. A literature review, including 22 published cases and our case, was performed to clarify the clinical characteristics of CCC in the base of the tongue.
  
  
  RESULTS
  The exophytic tumor showed no infiltration to the neighboring tissues. She underwent a local excision en bloc transorally and is free of the disease 15 months after surgery. In our review of 23 cases of CCC in the base of the tongue, 21 cases received surgical excision for the purpose of the primary treatment modality. The fact that the distinctive features of restricted site-related symptoms and the rare presentation of pain emerged was similar to previously reported cases of CCC. A relatively good prognosis was still indicated.
  
  
  CONCLUSIONS
  We reveal the features of the unusual occurrence of CCC in the base of the tongue and consider the appropriate surgical approach for primary treatment.
authors.affiliation: Department of Otolaryngology, Sendai Social Insurance Hospital, Sendai, Japan Department of Otorhinolaryngology-Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan kenw@orl.med.tohoku.ac.jp.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Otolaryngology, Sendai Social Insurance Hospital, Sendai, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Department of Otolaryngology, Sendai Social Insurance Hospital, Sendai, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Department of Pathology and Histotechnology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D005927:Glossectomy; D006801:Humans; D008875:Middle Aged; D014062:Tongue Neoplasms / Q000473:pathology* / Q000601:surgery
keywords: CCC; base of the tongue; clear cell carcinoma; minor salivary gland tumor