How to Investigate a Musculoskeletal Malignancy Frank O’Dea December 19, 2002

Introduction Primary Musculoskeletal tumors arise from tissue of mesenchymal origin (ie. bone, muscle, connective tissue, adipose.) These primary tumors may spread to other sites, usually other bones or lung. Secondary bone tumors arise from a host of other tissues and in the appropriate age category must be looked for.

Introduction The work-up of any tumor must be thought of in terms of Local disease and Systemic disease. By doing so you will have a sensible approach to determining the ultimate pathologic diagnosis and the extent of the disease in the body.

The Problem: A Lump in the Bone History Cause: Age, Age, Age, smoking, cancer, family history. Systemic: sweats, wt loss, fever, cough, hemoptesis, other lumps. Local: pain, nerve, lump, time frame.

The Problem: A Lump in the Bone Physical: Systemic: General physical, focus on the Benzene ring and sites of possible Metastases. (lung, breast, bowel, prostate, thyroid, renal). Local: Mass size, firmness, tenderness, inflamed, relationship to fascia, nerve, vascular, skin, lymph nodes.

Investigations *****Don’t think of your investigations in shotgun form.***** Focus your investigations based on the clinical scenario and then think of Local and Systemic investigations.

Local Investigations X-ray….the most helpful in focusing our differential and further investigations. Cat scan….. Bone architecture, neocorticalization, ?fracture. MRI….marrow extent, soft tissue extent, neurovascular involvement, skip lesions.

Investigations X-ray of proximal femur lesion

Investigations MRI of same lesion 1 day later after a fall.

Systemic Investigations: Radiology Total Body Bone Scan…..other lesions. Chest Cat scan… fine cut. What about CT chest/abdomen/pelvis??? Is there ever a role?

Systemic Investigations: Blood-work CBC, calcium, albumin, ESR, C-reactive protein, ALP, LDH. Why do you do these tests? Protein electrophoresis, PSA, PtH. What about LFT’s, RFT’s, magnesium, Ptt/Pt/INR??? Are they useful tests and if so when?

Other Specialized Investigations Bone Marrow Biopsy Angiography… when and why? Gallium Scan… when and why?

Invasive Investigation Biopsy…..the goal is to obtain a piece of tissue adequate to make a pathologic diagnosis. Should be done after all other investigations are complete Needle, Tru-cut, incisional. CT/US guided.

Biopsy In the OR…what do you want? Principles: “in line with eventual resection incision”…. Homan retractors????…. Tourniquet????….. Hemostasis????…. drain???…. multiple layer closure…. soft tissue mass…. round hole in bone …fixation???? Frozen section

Biopsy Frozen section Swabs for C+S, and any other things you may be thinking of (ie. Fungus, TB). Is it acceptable to proceed on the basis of Frozen section?

Incisional Biopsy vs Excisional Biopsy Is this pactice ever safe???