title: TUMORS OF THE PATELLA: THE EXPERIENCE OF INSTITUTE OF ORTHOPEDICS AND TRAUMATOLOGY AT UNIVERSITY OF SÃO PAULO, BRAZIL.
abstract: OBJECTIVE
  To obtain epidemiological data from the tumors of the patella diagnosed and treated at the Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Universidade de São Paulo (IOT-HC-FMUSP) between 1998 and 2015.
  
  
  METHODS
  Series of cases with retrospective evaluation of patients diagnosed with tumors located in the patella. The data was obtained from the records and patients' charts at the Department of Pathology of IOT-HC-FMUSP.
  
  
  RESULTS
  A total of 2220 medical records from patients with anatomopathological reports were included in the study. Only eight (0.3%) patients had patellar tumors. We found that six (75%) of these were benign, one (12.5%) was a pseudotumoral lesions and one (12.5%) was reported as malignant. Among benign tumors, the giant cell tumor (GCT) was the most frequently reported corresponding to 50% of the cases. Hemagioendothelioma was the only case of malignant tumor in this series. As for the pseudotumoral lesions, we found a brown tumor.
  
  
  CONCLUSIONS
  From the data obtained retrospectively in a 17 year time frame, in a service that treats benign, malignant and pseudotumoral bone lesions, we conclude that our casuistry in patellar tumors is similar to that reported in scientific literature, where benign tumors are predominant in a 7:1 ratio over malignant tumors, being a rare location of appearance, with the GCT as the most common diagnosis . Level of Evidence IV, Case Series.
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: André Mathias
authors.initials: AM
authors.lastname: Baptista
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Sylvio Cesar
authors.initials: SC
authors.lastname: Sargentini
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Zumárraga
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: André Ferrari De França
authors.initials: AF
authors.lastname: Camargo
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Olavo Pires De
authors.initials: OP
authors.lastname: Camargo
keywords: Biopsy.; Bone neoplasms; Patella