Calcifying fibrous pseudotumor causing thoracic outlet syndrome.

Calcifying fibrous pseudotumor (CFP) is a relatively rare benign mass lesion that generally involves the soft tissues. We report a case of CFP occurring in an extremely rare location. The patient is a 34-year-old woman presenting symptoms of numbness of her right upper extremity caused by a CFP in her thoracic outlet and we discuss its clinical significance with a review of the literature.