title: Sarcomatoid renal cell carcinoma presenting in the oropharynx.
abstract: Metastasis stemming from a distant malignancy is far less common than an oropharyngeal primary and represents only 1% of all oral neoplasms. The difficulty in diagnosing a metastasis in the oropharynx may be compounded if the lesion is poorly differentiated and bears little resemblance to the primary tumor. We present the case of synchronous metastatic renal cell carcinoma of the mandibular gingiva in a woman with sarcomatoid clear cell renal cell carcinoma. The metastatic lesion was poorly differentiated and lacked expression of the renal cell carcinoma (RCC) antigen. In contrast, PAX-8 staining was strongly positive. This case serves to highlight the diagnostic difficulty posed by poorly differentiated lesions in the oropharynx and reinforces the sensitivity of the cell lineage-specific transcription factor PAX-8 in poorly differentiated RCC.
authors.affiliation: Department of Dermatology, Northwestern University, Chicago, IL 60611, USA. bryan.gammon@gmail.com
authors.forename: Bryan Leigh
authors.initials: BL
authors.lastname: Gammon
authors.forename: Briana C
authors.initials: BC
authors.lastname: Gleason
authors.forename: Antoinette B
authors.initials: AB
authors.lastname: Thomas
authors.forename: Thomas Lee
authors.initials: TL
authors.lastname: Cibull
mesh_terms: D002292:Carcinoma, Renal Cell / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation; D003937:Diagnosis, Differential; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007680:Kidney Neoplasms / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins; D009959:Oropharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000556:secondary*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000096:biosynthesis
chemical_list: D009363:Neoplasm Proteins; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors