How To Approach a “bump”

1. Michelle Ghert, MD, FRCSC How To Approach a “bump”

2. 300/100,000 benign soft-tissue, but only 2/100,000 malignant soft-tissue Soft tissue sarcoma can occur at any age Rabdomyosarcoma most common in children Synovial & epitheliod sarcomas common in young adults Epidemiology:

3. 20-40% of STS occur in extremities 1/3 in upper extremities & 2/3 lower extremities 30% occur in trunk and pelvis. 10% occur in head & neck 1/3 of STS present as small superficial masses

6. STS & Their Tissue of Origin: • Fibrous Tissue • Adipose Tissue • Striated Tissue • Smooth Tissue • Synovial Tissue • Blood Vessels • Lymph Vessels • Peripheral Nerve • Myofibroblast • Fibroma/Fibrosarcoma • Lipoma/Liposarcoma • Rhabdomyoma/Sarco • Leiomyoma/Sarcoma • Mesothelioma • Angioma/Sarcoma • Lymphangioma/sarco • Neuroma/Schwannoma • Malignant Fibrous Histiocytoma

7. Superficial tender mass, red in color, rapidly enlarging, swollen, warm, fluctuant on examination? 1)Synovial cyst 2)Hematoma 3)Abscess Brain Storming:

8. Hx of direct trauma, therapeutic anticoagulation, clotting deficiency, subcutaneous ecchymosis, compressible on examination? 1)Abscess 2)Hematoma 3)Synovial Cyst

9. Para-articular mass, trans-illuminate, fluctuation in size independent of activities, tense but indentable with digit pressure on examination? Bakers cyst Hematoma Shwannoma Synovial Cyst

10. Malignant: Pleiomorphic Sarcoma Fibrosarcoma(FS) Liposarcoma Synovial Sarcoma Epitheliod Sarcoma Clear Cell Sarcoma Rhabdomyosarcoma Common Soft Tissue Lesions:

11. Benign: 1-Lipoma 2-Desmoid 3-Schwannoma 4-Hemangioma

12. Memorial Sloan-Kettering Clinical Staging: • Size: < 5cm • Depth: Superficial • Grade: Low >= 5cm Deep High

13. Low Grade: High Grade: • Good Differentiation • Hypocellular • More Stroma • Hypovascular • Minimal Necrosis • Poor Differentiation • Hypercellular • Minimal Stroma • Hypervascular • Much Necrosis Guideline To Histologic Grading Of Sarcomas:

14. Very little information is gained. Some infections may result in elevated: WBC, ESR & CRP But this finding nonspecific. Elevated lactate dehydrogenase seen in lymphoma. Suspicion of Gout----- Serum Uric Acid Laboratory Evaluation:

15. Confirm the diagnosis of a cyst Does mass have a cystic component? F/U a small mass that is being followed without excision Accurately asses an increase in growth of the mass by examining the change on the ultrasound studies Ultrasound:

16. Identifying and characterizing mineralization within the soft tissue masses(myositis ossification) Generally reserved for staging CT:

17. Most sensitive and specific radiograph study for imaging soft tissue masses Helpful for preoperative planning prior to excision the mass Excellent differentiation of various tissue types MRI:

21. Indication: 1- Clinical & radiographic evaluation does not yield a conclusive diagnosis 2-When the mass must be removed Biopsy of Soft Tissue Masses:

22. 1) The pathologist should have experience in musculoskeletal pathology 2)The surgeon should have experience in dealing with all of the possible diagnoses considered in the pre-biopsy differential diagnosis 2 Criteria Should be met before Proceeding:

23. Fine-needle aspiration Core-needle Open biopsy Types of soft tissue Biopsy:

24. Typically performed by an interventional or MSK radiologist Minimal morbidity for the patient Core is better than FNA Core is 85% diagnostic If non-diagnostic tissue is obtained, the mass should not be assumed to be benign Core and FNA:

26. Incision in line with resection incision Longitudinal in extremities Intramuscular if possible (to bury hematoma) Avoid NV structures and joints No skin or muscle flaps Meticulous hemostasis Tight closure Approach soft tissue mass or weakened area of bone Drain if necessary, in line and distal to incision Send tissue for frozen: ‘lesional tissue’ Open Biopsy:

27. Treatment of soft tissue masses is based on their size and location • 4 categories: • small superficial • large superficial • small deep • large deep The surgeon’s approach to a bump:

29. The piecemeal removal of the tumor. Benign proliferative lesions (PVNS, gout) Intralesional Excision:

30. Complete removal of the tumor with pseudocapsule left intact Benign tumors Marginal excision (Shell-out)

31. Removal of the tumor with a cuff of normal tissue without exposing the pseudocapsule Malignant soft-tissue lesions Wide excision:

32. Involves removal of the entire muscle compartment or compartments involved by the tumor Rare Radical excision:

33. Less than 5cm Easily palpable beneath the skin & not firm with muscle contracture Slow or stable growth pattern Long history Small superficial tumor:

34. If excisional biopsy is chosen, then marginal excision can be done Deep fascia should be left undisrupted

35. More than 5 cm. Easily felt beneath the skin, and not firm with muscle contracture. Large superficial tumor:

36. Almost always need evaluation with MRI • If a diagnosis is unclear by MRI, then biopsy

37. Less than 5 cm located in deep fascia Becomes more firm with muscle contracture Small deep mass should be always investigated by MRI Small deep tumor:

38. If MRI suggests a lipoma or peripheral nerve sheath mass (shwannoma), marginal excision Non-specific MRI may represent a soft tissue sarcoma

39. More than 5cm located deep to the fascia. MRI (high risk) Refer to musculoskeletal oncologist Large deep tumor:

40. Wide surgical excision Radiation, pre or post operative Chemotherapy, while controversial, can be considered for patient with high grade, large, deep soft tissue sarcoma Sarcoma management

41. Longstanding, small, static subcutaneous ‘bumps’ can be treated with ultrasound, observation and marginal excision if desired Rapid growth, deeper lesions and those 4-5 cm should be imaged with MRI High-risk lesions should not be excised, but biopsied Always use longitudinal incision in extremities Take home points for ‘bumps’

42. When in doubt, give us a call!