Pathology MSK tumors and non-tumors

Question 1

Soft vs bone/cartilage tumors

Answer 1

• Soft tumors: mesenchymal proliferation that occur in extraskeletal non-epithelial tissues
• Bone/cartilage: from the activity of bone or cartilage cells

Question 2

Deep vs superficial

Answer 2

• Superficial: may be locally invasive, but typically slow-growing, non-aggressive/metastatic
• Includes reactive lesions, benign neoplasms, low grade sarcomas
• Deep tissues: locally invasive, aggressive, more likely to metastasize
• High grade sarcomas, deep-seeded fibromatoses (these don’t metastasize)

Question 3

Who gets them

Answer 3

• Liposarcoma, lipoma, leiomyosarcoma, superficial fibromatosis: mostly over 40
• Fibrosarcoma, deep-seeded fibromatoses, nodular faciitis: mostly under 40
• Rhabdomyosarcoma: mostly under 20
• Osteochondroma, osteoid osteoma, osteosarcoma, ewing sarcoma: mostly under 20
• Chondroma, chondrosarcoma: mostly over 20
• Chondrosarcoma usually older ppl

Question 4

Superficial vs deep

Answer 4

• Superficial: nodular faciitis, superficial fibromatosis, lipoma, dermatofibroma, rhabdomyosarcoma (in head and neck), low-grade sarcomas
• Deep (including retroperitoneum): deep-seated fibromatosis, high-grade sarcomas, liposarcoma, leiomyosarcoma, fibrosarcoma (around knee for adults), rhabdomyosarcoma (muscles of extremities and GU)

Question 5

Where bone/cartilage tumors arise

Answer 5

• Epiphysis: chondroma
• Metaphysis: enchondroma (usually hands and feet), osteochondroma (legs), osteosarcoma (legs)
• Diaphysis: osteoid osteoma (legs), osteosarcoma
• Medullary cavity: ewing sarcoma
• Chondrosarcoma: central portion of skeleton, other places other than hands and feet