Differential diagnosis of a traumatic lateral hip lump

ConditionCauseDiagnostic cluesManagement
Hemorrhagic greater trochanter bursitis2Usually from direct trauma; bursa is located deep and is smallNormal hip range of motion; a fluctuating mass over the greater trochanter may be palpable; ultrasonography (US) or magnetic resonance imaging (MRI) necessary for diagnosisConservative management often adequate; if bursal enlargement is significant, US-guided aspiration warranted
Greater trochanter fracture3Typically from direct traumaPatient may or may not be able to bear weight; hip range of motion and resisted abduction often produce pain; greater trochanter tenderness is significant; plain radiography needed for the diagnosisReferral to an orthopedic surgeon is recommended; operative management required only with significant displacement
Intramuscular gluteus medius hematoma4Usually from direct trauma; may be concurrent with hip fractureUsually deep and not visible during the physical examination; US or MRI required for definitive diagnosisConservative management often adequate; in cases with significant enlarged hematoma, US-guided aspiration warranted
Morel-Lavallée lesion5Usually from shearing traumaMRI or US helpful for diagnosisDepending on type and stage of lesion, options may include watchful waiting, compression, aspiration, injection of sclerosing agent, drainage, and incision and evacuation