DISEASES SELF-SCORED SELF-
ASSESSMENT EXAMINATION
AAOS 2017
,Musculoskeletal Tumors and Diseases Self-Scored Self-Assessment Examination 2017 Ahmed Altaei
CLINICAL SITUATION FOR QUESTIONS 1 THROUGH 4
Figures 1a through 1d are the MR images and biopsy specimen of a 68-year-old man who has a
painless mass in his leg. He believes the mass may have been present for several years, and it is
more apparent now because he recently lost weight after changing his diet and exercise patterns.
He also recently experienced modest trauma to his leg while moving furniture.
Question 1 of 100
What is the diagnosis?
1- Dedifferentiated liposarcoma
2- Intramuscular lipoma
3- Atypical lipomatous tumor
4- Myositis ossificans
PREFERRED RESPONSE: 1- Dedifferentiated liposarcoma
Question 2 of 100
The role of surgery in this condition is best described as
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,Musculoskeletal Tumors and Diseases Self-Scored Self-Assessment Examination 2017 Ahmed Altaei
1- marginal resection is performed with a low likelihood of recurrence.
2- best performed after the lesion becomes “cold” on a bone scan.
3- wide resection as an indication for curative treatment.
4- not indicated.
PREFERRED RESPONSE: 3- wide resection as an indication for curative treatment.
Question 3 of 100
The role of radiation treatment for this lesion is
1- proven to decrease local recurrence.
2- associated with a high rate of post-radiation sarcoma development.
3- contra-indicated for benign pathology.
4- associated with a higher risk of wound complications if given post-operatively.
PREFERRED RESPONSE: 1- proven to decrease local recurrence.
Question 4 of 100
Chemotherapy for this condition is
1- contraindicated when pathology is benign.
2- associated with a high risk for subsequent myelodysplastic syndrome.
3- provides dramatic survival benefits.
4- provides modest survival benefits.
PREFERRED RESPONSE: 4- provides modest survival benefits.
DISCUSSION
This patient has a dedifferentiated liposarcoma within a preexisting atypical lipomatous tumor.
The imaging demonstrates a large fatty mass with increased internal septations proximally (the
atypical lipomatous tumor) and a solid enhancing mass distally (the dedifferentiated portion). A
biopsy reveals a high-grade liposarcoma. The other diagnostic responses do not reflect
sarcomatous transformation of the lesion.
Surgical treatment of a high-grade sarcoma involves wide surgical resection. Radiation decreases
local recurrence but does not clearly influence overall survival. The role of chemotherapy in high-
grade soft-tissue sarcomas remains investigational; there is a modest (8%-15%) associated
improvement in overall survival.
Intramuscular lipomas and atypical lipomatous tumors are treated with marginal resection alone.
Radiation therapy for soft-tissue sarcomas may be given before or after surgery. When
administered before surgery, patients have a higher wound complication rate but better long-term
function attributable to lower rates of lymphedema, fibrosis, and contractures.
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, Musculoskeletal Tumors and Diseases Self-Scored Self-Assessment Examination 2017 Ahmed Altaei
RECOMMENDED READINGS
• Schlieman M, Smith R, Kraybill WG. Adjuvant therapy for extremity sarcomas. Curr Treat Options
Oncol. 2006 Nov;7(6):456-63. Review. PubMed PMID: 17032558.View Abstract at PubMed
• Yang JC, Chang AE, Baker AR, Sindelar WF, Danforth DN, Topalian SL, DeLaney T, Glatstein E,
Steinberg SM, Merino MJ, Rosenberg SA. Randomized prospective study of the benefit of adjuvant
radiation therapy in the treatment of soft tissue sarcomas of the extremity. J Clin Oncol. 1998
Jan;16(1):197-203. PubMed PMID: 9440743.View Abstract at PubMed
• Soft tissue tumors. In: Damron TA, ed. Orthopaedic Surgery Essentials: Oncology and Basic Science.
Philadelphia, PA: Lippincott Williams and Wilkins; 2008:87-92
Question 5 of 100
Figures 5a and 5b are the radiographs of a 74-year-old man with poorly differentiated squamous
cell carcinoma of the lung. He has had an uneventful recovery after undergoing a wedge resection
of his left upper lobe 6 months ago. He is experiencing left lateral knee pain, and a whole-body
positron emission tomography/CT scan shows no avid area other than the lateral left distal femur.
This patient has needed to use a wheelchair for 3 weeks because of his pain. You discuss these
treatment options: aggressive curettage, local adjuvant treatment, cementation, and prophylactic
fixation vs distal femoral resection and megaprosthesis total knee arthroplasty reconstruction. You
should tell him that
1- his overall disease-free survival will be no different with either procedure.
2- fixation failure may occur with cementation and prophylactic fixation but not with
megaprosthesis reconstruction.
3- infection rates with megaprosthesis reconstruction are lower than with cementation after
aggressive curettage.
4- radiation will not be necessary after undergoing either procedure.
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