title: Primary intramuscular infestation of Echinococcus granulosus misdiagnosed as a soft tissue tumor: a case report.
abstract: BACKGROUND
  The occurrence of a primary intramuscular infestation of Echinococcus granulosus is extremely rare.
  
  
  METHODS
  A 70-year-old woman with primary skeletal muscle hydatidosis initially presented with a soft tissue mass. Clinical and radiologic examination revealed a huge cystic mass in the right quadriceps muscle without any visceral organ involvement. Since the differential diagnosis included a soft tissue tumor, fine needle aspiration cytology was performed, and a diagnosis of hydatid disease was made.
  
  
  CONCLUSIONS
  This very rare case of primary intramuscular infestation of E granulosus was clinically misdiagnosed as a soft tissue tumor. Hydatid disease, albeit rare, should be considered in the differential diagnosis of a soft tissue mass.
authors: Section of Pathology, Department of Biomorphological and Functional Sciences, University of Naples "Federico II", Naples, Italy. insabato@unina.it
authors: Luigi
authors: L
authors: Insabato
authors: Gilda
authors: G
authors: Marino
authors: Flavio
authors: F
authors: Fazioli
authors: Venanzio
authors: V
authors: Iacono
authors: Massimo
authors: M
authors: Mascolo
authors: Lucio
authors: L
authors: Palombini
mesh_terms: D000368:Aged; D000818:Animals; D003951:Diagnostic Errors; D004443:Echinococcosis / Q000175:diagnosis*; D048209:Echinococcus granulosus / Q000472:pathogenicity*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009135:Muscular Diseases / Q000469:parasitology*; D012983:Soft Tissue Neoplasms / Q000175:diagnosis*