30 - Benign and Malignant MSK Tumors Flashcards
What’s on your differential diagnosis if a child has a malignant bone tumor?
Osteosarcoma
Ewing’s sarcoma
Lymphoma
What’s on your differential diagnosis if an adult has a benign bone tumor?
Giant cell tumor or fibrous dysplasia
What are signs of rapid bone tumor growth?
Permeation of the cortex, large soft tissue mass, non-sclerotic rim (doesn’t have time to build a wall around it)
What are the ways in which the bone can produce a matrix? What type of tumor doesn’t make a matrix (lacks mineral)?
- Osteoid
- Chondroid
- Dystrophic calcification
Lack of mineral: mainly a cellular tumor that lacks matrix, fibrous tumor, cyst production
How would you work up a bone lesion with imaging?
- Xray of entire affected bone
- MRI
- Whole body scan (or skeletal survey)
- CT C/A/P or PET/CT
How do you work up a bone lesion with lab work?
Multiple myeloma: SPEP/UPEP/Serum free light chains
In prostate cancer: PSA
Inflammatory markers (crp, esr, cbc)
What are some common benign tumors?
- Nonossifying fibromas/fibrous cortical defect
- Osteochondroma/exostosis
- Osteoid osteoma
What is the most common bone lesion in children that’s benign?
Nonossifying fibroma - usually asymptomatic and normally heal on their own.
What is an osteochondroma and where does it occur? Are they benign or malignant? What can cause them?
Common bone lesions - metaphyseal (growth plate) location in long bones. Grows away from epiphysis; malignant transformation rare (<1%).
Multiple hereditary exostoses: aut dominant, EXT-1 mutation with 20-40% malignant transformation to low grade chondrosarcoma.
What are symptoms of an osteoid osteoma? Where are they usually located?
Gradually increasing pain, nocturnal exacerbation, relief with oral ASA or NSAIDs. COX and PG abundant.
Diaphysis of long bones, 50% femur.
How should you image an osteoid osteoma?
Xrays
CT scans
MRI may be helpful but there’s little surrounding ST reaction
Bone scans: nidus well localized..doesn’t help with differential
What are the classic treatment methods for an osteoid osteoma?
En bloc resection: pre-label with tetracyclin and observe under woods lamp
Local curettage: Local curettage and bone grafting
Observation: and symptomatic treatment. Looks for non-accessable lesions. Treat with ASA, naproxen, ibuprofen.
What is the gross appearance of osteoid ostemoa? What is the appearance on histology?
Gross: Less than 2cm, reddish color, soft tissue gritty due to osteoid. Surrounding reactive bone.
Histology: nidus surrounded by dense cortical reactive bone. Active nbuclei with benign characteristics. Osteoblastic rimming, vascularity.
What is the most common primary malignant bone tumor in adults? Describe this.
Multiple myeloma; this is actually a “bone marrow” tumor that consists of malignant plasma cells.
Cells make abnormal immunoglobulins that don’t fight infection well (IgG, IgA, IgM).
Light chains may be made as well.
What does multiple myeloma look like on radiographs?
Multiple bones, indistinct, moth-eaten lesions.
Not any reaction around the lesions; pathologic fractures occur in long bones and vertebrae.
Describe the other illnesses that are often found with multiple myeloma?
Systemic illness, anemia (BM overtaken by plasma cells), may be thrombocytopenic (bleed easily), renal compromise/failure.
Don’t fight infection well due to having the wrong immunoglobulins. Prone to infections and complications post-op.
How do you diagnose and treat multiple myeloma?
Biopsy a lesion and perform BM aspiration to diagnose. Subtypes by chromosomal analysis.
Treatment: chemo, stem cell transplant, treat pathologic fractures.
What is the most common neoplasm in bone? How does it cause death?
Metastatic carcinoma.
Primary tumor seldom the cause of death, disability and death is caused by invasion of vital organs and multi-system failure.
What are common cancers causing bone metastases?
BLTKP - breast, lung, thyroid, prostate, kidney.
80% of metastases originate in the ling, breast, and prostate.
The majority of destructive bone lesions in adults are caused by what?
Metastatic carcinoma: lesins may be lytic or blastic
What are the two types of pts presenting with skeletal metastases?
Pt with known primary tumor
Pt presenting with a destructuve bone lesion and unknown primary tumor
85% of primary tumors were diagnosed with what?
CT, total body bone scanm PET scans, or needle biopsy.
What are treatments for metastatic carcinoma?
- Treat impending fractures. with minimally invasive techniquies
- Radiation therapy to treat tumor and dminish pain
- Bisphosphate therapy (anto-osteoclast)
- Chemo
- Embolic treatment of vascular lesions