[ XXXX developing in the psoas major muscle: a case report].

@entity808 @entity1 @entity1313 @entity5 @entity809 @entity16 @entity615
@entity808 can occur wherever peripheral nerve Schwann cells are found. However, @entity808 is extremely rare in that only 16 cases have been reported, including that of the present @entity1 . A 51-year-old male complained of @entity615 and @entity809 in the lower left region. @entity615 increased with leftward bending. Magnetic resonance imaging (MRI) revealed a @entity1313 about 6 cm in diameter in the left psoas major muscle, and the lesion was in contact with the L4 and L5 vertebral bodies. The @entity5 did not continue to the lumbar foramen. The symptom had become disabling, therefore @entity5 removal was performed using Wiltse's approach. From intraoperative findings, the origin of the @entity5 was suspected to be the L4 nerve root. The ventral surface of the @entity5 could not be observed with this posterior approach. Lumbar plexus might adhere closely to the ventral surface of the @entity5 , therefore the capsule of the @entity5 was left to avoid @entity16 . @entity808 was diagnosed by pathological analysis, and no malignancy was evident. After the operation, symptoms were completely relieved, and the residual capsule of the @entity5 diminished in size on MRI after 12 months. The posterior Wiltse's approach can be useful to treat mass lesions in the psoas major muscle. The 16 reported cases of @entity808 , including that of the present @entity1 , are reviewed.
