PEM Case of the Week
By: Yvonne Giunta, MD
Chief Complaint: Leg pain
Vitals:
BP 110/76 HR 118 RR 22 Temp 98.6 F PO2 98% RA
8 yr old male presents to the ED complaining of left leg pain after fall while running. Patient states he was running and hit his left thigh into the edge of a chair. Has been limping since injury which occurred earlier the same day. Denies any head injury, vomiting, or LOC. No other complaints.
Pertinent Physical Exam:
Constitutional: Well appearing, no distress
MSK: Able to weight bear but with a limp secondary to pain to left leg. No obvious deformity to left thigh, knee or tib/fib. + tenderness to lateral aspect of left distal femur .
Plan:
Acetaminophen
Xray left femur and knee
Xray findings:
Femur:
Ill-defined sclerosis within the distal femoral metadiaphysis with possible extension across the physis. Faint periosteal reaction along the distal femoral diaphysis. Moth-eaten irregularity along the distal femoral cortex with associated cloudlike hyperdensities within the adjacent soft tissues spinous suspicious for associated mass.
IMPRESSION:
Aggressive osseous lesion in the distal femur with possible extension into the physis and likely partially calcified soft tissue mass. Findings are concerning for neoplasm such as osteosarcoma.
Diagnosis:
Osteosarcoma
Osteosarcoma Facts - Summary of UTD and PEM Morsel attached below:
Incidence – ~5 per 1,000,000
The most common primary bone tumor in patients < 40 years of age.
Production of osteoid (new bone) or immature bone by the malignant cells.
Bimodal peak incidence in the elderly and in adolescents.
Presentation usually with insidious pain localized at the primary tumor site of several weeks' duration or sometimes with a pathologic fracture.
Pain with activity is most common complaint.
“Growing Pains” is often the original misdiagnosis.
Location:
Most arise in the intramedullary space of the metaphysis
Most often in the long bones of the lower extremities.
~50% involve the knee (Distal Femur and Proximal Tibia)
May present with limp due to pain.
Xray appearance:
Lytic and blastic bone lesion
“Sunburst” appearance ( see pics)
Codman triangle (see picture)
Alkaline phosphatase and lactate dehydrogenase may be elevated although not diagnostic
Metastasizes to the Lungs and other distant bones primarily