title: Mixed embryonal/alveolar rhabdomyosarcoma of the prostate: report of a case with molecular genetic studies and literature review.
abstract: Alveolar rhabdomyosarcoma (RMS) is 1 of 2 main subtypes of RMS in the pediatric age group and tends to occur in the extremities. The urogenital tract is another common site for RMS, but this typically involves the embryonal subtype including sarcoma botryoides. We report a 28-year-old male with a prostatic tumor that was excised en bloc and showed a RMS with separate areas of embryonal and solid alveolar morphologies at the light microscopic level. Both areas showed diffuse nuclear expression for myogenin, and both areas expressed the PAX3-FKHR fusion gene, a genetic change associated with alveolar but not embryonal RMS. A review of the literature documented only 5 cases of RMS primary to the prostate showing alveolar or mixed histology. Ours is the 6th case and the 1st with molecular findings. Although the diagnostic category of mixed embryonal/alveolar RMS remains in use, the nature of this type of RMS is incompletely understood. In our case, although the morphology was mixed embryonal/alveolar, at the genetic level this tumor was alveolar in nature.
authors.affiliation: Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Jitsupa
authors.initials: J
authors.lastname: Treetipsatit
authors.forename: Wipawee
authors.initials: W
authors.lastname: Kittikowit
authors.forename: Maria
authors.initials: M
authors.lastname: Zielenska
authors.forename: Mookda
authors.initials: M
authors.lastname: Chaipipat
authors.forename: Paul Scott
authors.initials: PS
authors.lastname: Thorner
authors.forename: Shanop
authors.initials: S
authors.lastname: Shuangshoti
mesh_terms: D000328:Adult; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018193:Neoplasms, Complex and Mixed / Q000235:genetics / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018232:Rhabdomyosarcoma, Alveolar / Q000235:genetics / Q000473:pathology*; D018233:Rhabdomyosarcoma, Embryonal / Q000235:genetics / Q000473:pathology*
chemical_list: D015514:Oncogene Proteins, Fusion; C523321:PAX3-FKHR fusion protein, human