Desmoid fibromatosis presenting as lateral hip pain in an outpatient physical therapy clinic: A case report

Case Description: A 21-year-old healthy female presented with severe left lateral hip pain beginning suddenly two weeks prior. Physical examination revealed zero degrees of left hip external rotation passive range of motion with a firm end feel and pain severity and irritability out of proportion to an expected musculoskeletal presentation. She was referred to her physician with a recommendation for imaging to determine the source of pain and appropriateness of physical therapy. Outcome: Magnetic resonance imaging revealed a foreign mass in her left gluteus medius muscle which biopsy revealed to be a desmoid fibromatosis. Conclusion: This case demonstrates a thorough differential diagnostic process leading to medical imaging referral in a patient with a non-musculoskeletal source of pain. Physical therapists must be diligent in their differential diagnostic process to ensure appropriateness of their treatments or the need for referral.