title: Coccidiomycosis infection of the patella mimicking a neoplasm - two case reports.
abstract: BACKGROUND
  Coccidioidomycosis is an endemic fungal infection in the southwestern of United States. Most infections are asymptomatic or manifest with mild respiratory complaints. Rare cases may cause extrapulmonary or disseminated disease. We report two cases of knee involvement that presented as isolated lytic lesions of the patella mimicking neoplasms.
  
  
  METHODS
  The first case, a 27 year-old immunocompetent male had progressive left anterior knee pain for four months. The second case was a 78 year-old male had left anterior knee pain for three months. Both of them had visited general physicians without conclusive diagnosis. A low attenuation lytic lesion in the patella was demonstrated on their image studies, and the initial radiologist's interpretation was suggestive of a primary bony neoplasm. The patients were referred for orthopaedic oncology consultation. The first case had a past episode of pulmonary coccioidomycosis 2 years prior, while the second case had no previous coccioidal infection history but lived in an endemic area, the central valley of California. Surgical biopsy was performed in both cases due to diagnostic uncertainty. Final pathologic examination revealed large thick walled spherules filled with endospores establishing the final diagnosis of extrapulmonary coccidioidomycosis.
  
  
  CONCLUSIONS
  Though history and laboratory findings are supportive, definitive diagnosis still depends on growth in culture or endospores identified on histology. We suggest that orthopaedic surgeons and radiologists keep in mind that chronic fungal infections can mimic osseous neoplasm by imaging.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Li
authors.forename: George
authors.initials: G
authors.lastname: Calvert
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hanrahan
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Jones
authors.affiliation: Sarcoma Services, Department of Orthopaedics, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, USA. Lor.Randall@hci.utah.edu.
authors.forename: Robert Lor
authors.initials: RL
authors.lastname: Randall
mesh_terms: D000328:Adult; D000368:Aged; D003047:Coccidioidomycosis / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D003937:Diagnosis, Differential; D005266:Femoral Neoplasms / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010329:Patella / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed