Introduction and objectives: To report to the literature a new case of primary psoas abscess.
Methods: The patient is a 65 years old woman who suffered back and left hip pain for approximately 1 month. A CTA showed a retroperitoneal mass that involved the left Psoas. It was drained 1800 cc of purulent fluid infected by Streptococo pneumoniae.
Results: In a CTA made 21 days after drainage, showed a very small residual collection.
Conclusions: Primary Psoas Abscess are a very rare entity, with a low rate of mortatility if well treated.