title: Solitary fibrous tumor with atypical histological features occurring in the palatine tonsil: an uncommon neoplasm in an uncommon site.
abstract: Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm that usually arises in the pleura. Although this tumor has been described in other sites, including the head and neck area, in the oropharynx it is extremely rare. We report the first case of a SFT arising from the palatine tonsil of a 62-year-old man. The tumor consisted of spindle-shaped cells distributed in a haphazard pattern and presented atypical histological features such as hypercellular areas and high mitotic count. Immunohistochemical studies showed strong positivity for CD34 and bcl-2, and weak positivity for desmin. Smooth muscle actin, S-100 protein and cytokeratines were negative. The patient was well without disease 1 year after surgery.
authors.affiliation: Department of Pathology, Faculdade de Medicina de Botucatu, State University of Sao Paulo, Botucatu (SP), Brazil. rsmacarenco@yahoo.com.br
authors.forename: Ricardo Silvestre
authors.initials: RS
authors.lastname: Macarenco
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Bacchi
authors.forename: Maria Aparecida Custódio
authors.initials: MA
authors.lastname: Domingues
mesh_terms: D000071443:12E7 Antigen; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D003937:Diagnosis, Differential; D005350:Fibroma / Q000737:chemistry / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D014066:Palatine Tonsil / Q000737:chemistry / Q000473:pathology*; D014067:Tonsillar Neoplasms / Q000737:chemistry / Q000473:pathology*; D016896:Treatment Outcome; D051028:bcl-2-Associated X Protein / Q000032:analysis
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D009363:Neoplasm Proteins; D051028:bcl-2-Associated X Protein