This practice set contains high-yield board review questions covering key concepts in 10. Pathology and Oncology. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 1501
Topic: 10. Pathology and Oncology
..Figures 112a and 112b are the anteroposterior and lateral radiographs of a 65-year-old man who has a significant history of tobacco abuse and a 6-week history of right thigh pain. Axial and sagittal MRI scans are seen in Figures 112c and 112d. His MR angiogram is shown in Figure 112e. A biopsy of a lesion is shown in Figure 112f. What is the most likely diagnosis?
Correct Answer & Explanation
. Secondary sarcoma in a pre-existing condition
Explanation
CLINICAL SITUATION FOR QUESTIONS 113 THROUGH 116Figures 113a and 113b are the radiographs of a 68-year-old-man who has increasing pain in his left groin with weight-bearing activities and a Trendelenburg gait. Radiographs reveal a lytic lesion of the greater trochanter. An initial diagnosis of adenocarcinoma of the lung was made 1 year before this presentation. His lung cancer treatment consisted of partial lobectomy and postsurgical radiation therapy.
Question 1502
Topic: 10. Pathology and Oncology
A 51-year-old woman has had progressively increasing right knee pain for the past 6 months. She has a history of metastatic renal cell carcinoma to the lung and the skeletal system. Radiographs are seen in Figures 18a and 18b. The next step in management of the right distal femur lesion should consist of
Correct Answer & Explanation
. a technetium Tc 99m bone scan and AP and lateral radiographs of the entire right femur.
Explanation
DISCUSSION: In a patient with known metastatic disease, the surgeon must rule out additional lesions throughout the femur prior to surgical management. Lesions located in the diaphysis or in the peritrochanteric region may influence the surgical procedure.REFERENCES: Frassica FJ, Gitelis S, Sim FH: Metastatic bone disease: General principles, pathophysiology, evaluation, and biopsy. Instr Course Lect 1992;41:293-300.Sim FH: Metastatic bone disease of the pelvis and femur. Instr Course Lect 1992;41:317-327.
Question 1503
Topic: 10. Pathology and Oncology
An otherwise healthy 75-year-old man has a painful mass in the popliteal fossa of his right knee. A lateral radiograph of the knee, a CT scan of the distal femur, and a histopathologic specimen are shown in Figures 13a through 13c. Management should consist of
Correct Answer & Explanation
. surgical resection.
Explanation
DISCUSSION: The patient has a parosteal osteosarcoma of the distal femur. The findings of mild knee pain, radiographic evidence of a radiodense mass involving the parosseous space or surface of the distal femur, and histologic findings of a spindle cell lesion forming immature osteoid with little to no necrosis most likely suggest a parosteal osteosarcoma. The treatment of choice is surgical resection.REFERENCES: Okada K, Frassica FJ, Sim FH, Beabout JW, Bond JR, Unni KK: Parosteal osteosarcoma: A clinicopathological study. J Bone Joint Surg Am 1994;76:366-378.Campanacci M: Bone and Soft Tissue Tumors. New York, NY, Springer-Verlag, 1990, pp 433-454.
Question 1504
Topic: 10. Pathology and Oncology
..A 60-year-old woman has a proximal femur fracture. A permeative, lytic defect is recognized at the fracture site. Appropriate imaging studies are performed and show no other lesions. What is the next treatment step?
Correct Answer & Explanation
. Open biopsyDISCUSSION..In this patient, tissue diagnosis should be obtained prior to any surgical intervention to avoid unnecessary contamination in the event the lesion is a sarcoma. Open biopsy will yield thediagnosis in the majority of cases. The specific choice for surgical treatment of a proximal femur pathologic fracture is controversial, but it would typically involve either a cephalomedullary nail or resection/reconstruction. A simple antegrade femoral nail rarely is sufficient in this setting.
Explanation
CLINICAL SITUATION FOR QUESTIONS 7 THROUGH 9
Question 1505
Topic: 10. Pathology and Oncology
A 54-year-old woman reports worsening pain in her buttock, especially when sitting for long periods of time. She has occasional pain and paresthesias radiating down her posterior leg. She has no significant medical history. MRI scans are shown in Figures 15a and 15b and a biopsy specimen is shown in Figure 15c. What is the most likely diagnosis?
Correct Answer & Explanation
. Myxoid liposarcoma
Explanation
DISCUSSION: The biopsy specimen shows a wavy collagenous matrix with elongated cells; this is most consistent with neurofibroma. The patient has a mass in the region of the sciatic nerve. Imaging characteristics, homogeneous and very low signal on T1-weighted and very high signal on the T2-weighted sequences, are consistent with a myxoid-type lesion. These include myxoma, myxoid sarcomas, and nerve sheath tumors.REFERENCES: Campanacci M: Bone and Soft Tissue Tumors, ed 2.New York, NY, Springer-Verlag, 1999, pp 1135-1136Menendez LR: Orthopaedic Knowledge Update: Musculoskeletal Tumors.Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 251.
Question 1506
Topic: 10. Pathology and Oncology
A 31-year-old woman has increasing pain and tightness in her right knee, with occasional stiffness and recurrent hemorrhagic effusions. MRI scans are shown in Figures 2a and 2b. What is the most likely diagnosis?
Correct Answer & Explanation
. Rheumatoid arthritis
Explanation
DISCUSSION: PVNS is a rare inflammatory granulomatous condition of unknown etiology, and causes proliferation of the synovium of joints, tendon sheaths, or bursa. The disorder occurs most commonly in the third and fourth decades but can occur at any age. MRI provides excellent delineation of the synovial disease. Characteristic features of PVNS on MRI include the presence of intra-articular nodular masses of low signal intensity on T1- and T2-weighted images and proton density-weighted images. Synovial biopsy should be performed if there is any doubt of the diagnosis. Total synovectomy (open or arthroscopic) is required for the diffuse form, although recurrence is common. Rheumatoid arthritis and synovial chondromatosis are not typically associated with hemorrhagic effusions.REFERENCES: De Ponti A, Sansone V, Malchere M: Result of arthroscopic treatment of pigmented villonodular synovitis of the knee. Arthroscopy 2003;19:602-607.Chin KR, Barr SJ, Winalski C, et al: Treatment of advanced primary and recurrent diffuse pigmented villonodular synovitis of the knee. J Bone Joint Surg Am 2002;84:2192-2202.Bhimani MA, Wenz JF, Frassica FJ: Pigmented villonodular synovitis: Keys to early diagnosis. Clin Orthop 2001;386:197-202.
Question 1507
Topic: 10. Pathology and Oncology
A 70-year-old former baseball catcher reports long-standing pain in the ring and little fingers. A gradient-echo MRI scan is shown in Figure 26. What is the most likely diagnosis?
Correct Answer & Explanation
. Ulnar artery aneurysm
Explanation
DISCUSSION: The gradient-echo MRI scan highlights the ulnar and radial arteries,as indicated by the arrow. This technique suppresses the signal of the surrounding fatand causes the stationary surrounding tissues to become intermediate in signal intensity.The flowing blood is then easily identified with a bright signal because it does not absorb the radiofrequency pulse. Based on the findings, the diagnosis is an ulnar artery aneurysm, most likely caused by years of repetitive trauma as the result of catching baseballs. Neurolemmoma and giant cell tumor of the tendon sheath would be intermediately enhanced on this image sequence, and the continuity with the ulnar artery, demonstrated here, would not be expected. Lipomas are not enhanced using the gradient-echo technique. The chronic nature of the patient’s symptoms is not indicative of a hematoma, and the hematoma would be dark on this imaging sequence since it is stationary tissue.REFERENCES: Koman LA, Ruch DS, Patterson Smith B, et al: Vascular disorders, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, vol 2, pp 2254-2302.Holder LE, Merine DS, Yang A: Nuclear medicine, contrast angiography, and magnetic resonance imaging for evaluating vascular problems in the Hand: Vasospastic disorders. Hand Clin 1993;9:95-113.
Question 1508
Topic: Soft Tissue Tumors & Metastasis
Figures 34a through 34c show an axial proton density (spin echo long TR, short TE) image, a sagittal inversion recovery (STIR) image, and a sagittal T1-weighted (short TR, short TE) image of the left thigh. What is the most likely diagnosis?
Correct Answer & Explanation
. Hematoma
Explanation
DISCUSSION: The images reveal a region of increased signal within the rectus femoris muscle with mild, ill-defined surrounding edema. The presence of high intensity signal on the T1-weighted image favors acute blood, in this case associated with a rectus femoris muscle tear or fatty tissue. However, because of fat suppression, a fatty lesion or lipoma would be dark on STIR, rather than bright as in this image. Most foreign bodies are low intensity signal and if small, are difficult to evaluate with MRI. The lack of adjacent subcutaneous soft-tissue edema or surrounding fluid makes pyomyositis an unlikely diagnosis.REFERENCE: El-Khoury G: MRI of the Musculoskeletal System. Philadelphia, PA, JB Lippincott, 1998, p 123.
Question 1509
Topic: 10. Pathology and Oncology
A 56-year-old man has upper thoracic pain after undergoing stereotactic radiosurgery for a blastic metastatic lesion in the vertebral body of T5. He has normal alignment without collapse, but the tumor involves the entire vertebral body. Which factor increases this patient's risk for a pathologic fracture?
Correct Answer & Explanation
. Location of the lesion at T5
Explanation
DISCUSSIONCriteria for spinal instability have been outlined by the Spine Oncology Study Group, which developed the Spinal Instability Neoplastic Score (SINS) criteria. Factors associated with lower risk for instability/fracture are location outside of a junctional level (the SINS criteria use C7-T2 as the junctional level),blastic metastases, and no evidence of vertebral collapse (even with more than 50% involvement). Radiation has been associated with risk for pathologic fracture, and stereotactic radiation has been associated with risk for a spinal fracture.RECOMMENDED READINGSFisher CG, DiPaola CP, Ryken TC, Bilsky MH, Shaffrey CI, Berven SH, Harrop JS, Fehlings MG, Boriani S, Chou D, Schmidt MH, Polly DW, Biagini R, Burch S, Dekutoski MB, Ganju A, Gerszten PC, Gokaslan ZL, Groff MW, Liebsch NJ, Mendel E, Okuno SH, Patel S, Rhines LD, Rose PS, Sciubba DM, Sundaresan N, Tomita K, Varga PP, Vialle LR, Vrionis FD, Yamada Y, Fourney DR. A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group. Spine (Phila Pa 1976). 2010 Oct 15;35(22):E1221-9. doi: 10.1097/BRS.0b013e3181e16ae2. Review. PubMedPMID:20562730.View Abstract at PubMedFourney DR, Frangou EM, Ryken TC, Dipaola CP, Shaffrey CI, Berven SH, Bilsky MH, Harrop JS, Fehlings MG, Boriani S, Chou D, Schmidt MH, Polly DW, Biagini R, Burch S, Dekutoski MB, Ganju A, Gerszten PC, Gokaslan ZL, Groff MW, Liebsch NJ, Mendel E, Okuno SH, Patel S, Rhines LD, Rose PS, Sciubba DM, Sundaresan N, Tomita K, Varga PP, Vialle LR, Vrionis FD, Yamada Y, Fisher CG. Spinal instability neoplastic score: an analysis of reliability and validity from the spine oncology study group. J Clin Oncol. 2011 Aug 1;29(22):3072-7. doi:10.1200/JCO.2010.34.3897. Epub 2011 Jun 27. PubMed PMID: 21709187.View AbstractatPubMedRose PS, Laufer I, Boland PJ, Hanover A, Bilsky MH, Yamada J, Lis E. Risk of fracture after single fraction image-guided intensity-modulated radiation therapy to spinal metastases. J Clin Oncol. 2009 Oct 20;27(30):5075-9. doi: 10.1200/JCO.2008.19.3508. Epub 2009 Sep 8.PubMed PMID: 19738130View Abstract at PubMed
Question 1510
Topic: 10. Pathology and Oncology
A 16-year-old boy has had left knee pain and swelling after sustaining a minor twisting injury while playing basketball 2 weeks ago. Figures 5a through 5e show the radiograph, MRI scans, and biopsy specimens. What is the most likely diagnosis?
Correct Answer & Explanation
. Osteomyelitis
Explanation
DISCUSSION: The imaging studies and histology are most consistent with Ewing’s sarcoma. Tuberculosis can show small round blue cells on histology (lymphocytes associated with chronic infection) but would more typically involve the knee joint and periarticular bone. Osteosarcoma and MFH do not have small round blue cells histologically.REFERENCES: Sissons HA, Murray RO, Kemp HBS: Orthopaedic Diagnosis. Berlin, Springer-Verlag, 1984, pp 254-256.Wafa H, Grimer RJ: Surgical options and outcomes in bone sarcoma. Expert Rev Anticancer Ther 2006;6:239-248.
Question 1511
Topic: 10. Pathology and Oncology
A 21-year-old man has mild but persistent aching pain in his left proximal thigh during impact loading activities. He denies pain at rest and has no other symptoms. Figures 34a through 34e show the radiographs and T1-weighted, T2-weighted, and gadolinium MRI scans of the left hip. What is the most likely diagnosis?
Correct Answer & Explanation
. Enchondroma
Explanation
DISCUSSION: The radiographs show a centrally located radiolucent lesion with cortical thinning and mild osseous expansion; these findings are the hallmarks of a simple bone cyst. Whereas this particular lesion does not demonstrate sclerosis, the distinct margin of this lesion with sharp transition to normal bone is common. The MRI scans reveal a purely cystic lesion with bright T2 signal, and the gadolinium image shows the classic rim enhancement of cystic lesions. Fibrous dysplasia with cystic degeneration might have a very similar appearance and should be considered in the differential diagnosis.REFERENCES: Parsons TW: Benign bone tumors, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1027-1035.May DA, Good RB, Smith DK, et al: MR imaging of musculoskeletal tumors and tumor mimickers with intravenous gadolinium: Experience with 242 patients. Skeletal Radiol 1997;26:2-15.Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 4023-4034.
Question 1512
Topic: 10. Pathology and Oncology
Which of the following benign bone lesions can develop lung metastases?
Correct Answer & Explanation
. Chondroblastoma
Explanation
DISCUSSION: Although considered benign bone lesions, lung metastases can develop in giant cell tumors and chondroblastomas. These often can be treated with multiple thoracotomies, resulting in long-term survival.REFERENCES: Roberts PF, Taylor JG: Multifocal benign chondroblastomas: Report of a case. Hum Pathol 1980;11:296-298.Bloem JL, Mulder JD: Chondroblastoma: A clinical and radiological study of 104 cases. Skeletal Radiol 1985;14:1-9.
Question 1513
Topic: 10. Pathology and Oncology
Serum parathyroid hormone level The plain radiograph of the shoulder shows lytic lesions in the scapular spine, distal clavicle, and the proximal third of the clavicle. There is an elliptical erosion in the proximal clavicle. These three lesions suggest a diagnosis of metastatic bone disease or multiple myeloma. The biopsy specimen shows plasma cells. The plasma cells have these characteristic features: Eccentrically placed nucleus Peripheral clumping of the nuclear chromatin A perinuclear halo The diagnosis is multiple myeloma. Staging is important and is performed with a skeletal survey, bone marrow biopsy, hemoglobin level, and chemistry studies including kidney function and serum calcium determination. Serum protein electrophoresis is performed to assess the amount of abnormal gammaglobulin in the serum. There are three major criteria in the diagnosis of multiple myeloma:
Correct Answer & Explanation
. Monoclonal immunoglobulin spike on serum protein electrophoresis exceeding 3.5 g/dl for G peaks or 2.0 g/dl for A peaks or 1.0 g/24 hours of kappa or lamba light chain excretion on urine electrophoresis
Explanation
Slide 1 Slide 2A 55-year old man presents with a 4-month history of shoulder discomfort. The plain radiographs are shown in Slide 1 and a biopsy in Slide 2. Which of the following tests will probably be abnormal:
Question 1514
Topic: Soft Tissue Tumors & Metastasis
Examination of the shoulder seen in Figure 52 shows atrophy and tenderness of the infraspinous fossa and profound weakness in external rotation. The supraspinous fossa shows normal muscle bulk. What is the most likely cause of this condition?
Correct Answer & Explanation
. Ganglion cyst of the spinoglenoid notch
Explanation
DISCUSSION: Compression of the suprascapular nerve by a ganglion cyst is a well-documented cause of pain and weakness in the shoulder. Isolated involvement of the infraspinatus indicates that the area of entrapment is at the spinoglenoid notch and not the suprascapular notch. The majority of ganglion cysts found in the shoulder are related to tears of the labrum. When such a compressive lesion is found, decompression can be accomplished through either an open or arthroscopic approach. Several authors have shown the value of arthroscopy in the treatment of this condition. It has been shown that it is technically possible to decompress a paralabral ganglion cyst using arthroscopy; this method is usually followed by repair of the torn labrum. Alternatively, arthroscopic repair of the labrum can be performed and the cyst may be aspirated at the time of surgery. Open cyst excision through a posterior approach is also an acceptable method of treatment.REFERENCES: Schickendantz MS, Ho CP: Suprascapular nerve compression by a ganglion cyst: Diagnosis by magnetic resonance imaging. J Shoulder Elbow Surg 1993;2:110-114.Thompson RC, Schneider W, Kennedy T: Entrapment neuropathy of the inferior branch of the suprascapular nerve by ganglia. Clin Orthop 1982;166:185-187.Iannotti JP, Ramsey ML: Arthroscopic decompression of a ganglion cyst causing suprascapular nerve compression. Arthroscopy 1996;12:739-745.
Question 1515
Topic: 10. Pathology and Oncology
Figure 2 shows the radiograph of a 72-year-old woman who reports pain after a fall. History includes several years of increasing thigh pain and limb shortening. Management consisting of an extensive work-up for infection reveals normal laboratory studies, a positive bone scan, and a negative hip aspiration. What is the most likely etiology of this complication?
Correct Answer & Explanation
. Loosening of the prosthesis
Explanation
DISCUSSION: The patient has a midstem periprosthetic fracture, which commonly results in loosening of the prosthesis. Patients who have a large amount of bone loss may require an allograft with the surgical reconstruction. Although the patient reported a fall, her history is also consistent with preexisting loosening of the prosthesis. Chronic infection has been shown in up to 16% of these fractures; however, the patient’s work-up revealed no infection.REFERENCES: Garbuz DS, Masri BA, Duncan CP: Periprosthetic fractures of the femur: Principles of prevention and management, in Cannon WD Jr (ed): Instructional Course Lectures 47. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 237-242.Bethea JS III, DeAndrade JR, Fleming LL, Lindenbaum SD, Welch RB: Proximal femoral fractures following total hip arthroplasty. Clin Orthop 1982;170:95-106.Kelley SS: Periprosthetic femoral fractures. J Am Acad Orthop Surg 1994;2:164-172.
Question 1516
Topic: 10. Pathology and Oncology
A 13-year-old girl has had increasing left hip pain for the past 4 months. A radiograph, bone scan, MRI scan, and photomicrograph are shown in Figures 1a through 1d. Which of the following immunohistochemistry results would confirm the most likely diagnosis?
Correct Answer & Explanation
. MIC-2 positive
Explanation
DISCUSSION: The imaging studies show a permeative lesion of the left hemipelvis with a large soft-tissue mass. The photomicrograph demonstrates a small blue cell tumor with pseudorosettes. The most likely diagnosis is primitive neuroectodermal tumor (Ewing’s sarcoma family of tumors). MIC-2 is a highly sensitive and specific marker for this family of tumors. Cytokeratin is an epithelial marker. Vimentin is a mesenchymal marker. Thus, Ewing’s sarcomas are cytokeratin negative and vimentin positive. Before discovery of the MIC-2 antigen, PAS and reticulin stains were commonly used to help differentiate Ewing’s sarcoma from lymphoma. In contrast to lymphoma, Ewing’s sarcomas are typically PAS positive and reticulin negative.REFERENCES: Halliday BE, Slagel DD, Elsheikh TE, et al: Diagnostic utility of MIC-2 immunocytochemical staining in the differential diagnosis of small blue cell tumors. Diagn Cytopathol 1998;19:410-416.Llombart-Bosch A, Navarro S: Immunohistochemical detection of EWS and FLI-1 proteins is Ewing sarcoma and primitive neuroectodermal tumors: Comparative analysis with CD99(MIC-2) expression. Appl Immunohistochem Mol Morphol 2001;9:255-260.
Question 1517
Topic: 10. Pathology and Oncology
A 30-year-old patient has wrist pain. A radiograph and biopsy specimen are shown in Figures 34a and 34b. What is the most likely diagnosis?
Correct Answer & Explanation
. Aneurysmal bone cyst
Explanation
DISCUSSION: Aneurysmal bone cysts typically present as radiolucent lesions with an expansile remodeled cortex. The histologic appearance consists of blood-filled lakes surrounded by a benign lining that contains fibroblasts, giant cells, and hemosiderin. Although the other lesions are in the radiographic differential diagnosis, these histologic findings indicate an aneurysmal bone cyst.REFERENCES: Bieselker JL, Marcove RC, Huvos AG, Mike V: Aneurysmal bone cyst: A Clinico-pathologic study of 66 cases. Cancer 1973;26:615.Martinez V, Sissons HA: A review of 123 cases including primary lesions and those secondary to other bone pathology. Cancer 1988;61:2291.
Question 1518
Topic: 10. Pathology and Oncology
Figure 26 shows the radiograph of a 48-year-old woman who has right arm pain and hematuria. A bone scan reveals increased uptake in the left ribs and thoracic spine. A needle biopsy specimen shows that the lesion is highly keratin positive and composed primarily of clear cells. What is the best course of action?
Correct Answer & Explanation
. Embolization followed by curettage, intramedullary fixation, and cementation
Explanation
DISCUSSION: The lesion has the typical “blown out” lytic radiographic appearance that is most commonly found in thyroid or renal cell metastases. Given the history of hematuria and histology findings, the most likely diagnosis is metastatic renal cell carcinoma. This tumor is relatively resistant to chemotherapy. Radiation therapy is used as a postoperative adjuvant treatment with varying response rates. Surgery should be performed after preoperative embolization to decrease the risk of intraoperative bleeding, as no tourniquet can be used in this location. Patients with metastatic renal cell carcinomas may survive for years, resulting in a higher likelihood of local tumor progression with ineffective adjuvant therapy. Intramedullary fixation combined with curettage and cementation will provide the best chance of local control while maintaining the patient’s native shoulder and elbow joints. A total humeral resection is an extensive surgery with considerable morbidity and is not indicated for this patient because less extensive surgery is likely to be effective.REFERENCES: Harrington KD, Sim FH, Enis JE, Johnston JO, Diok HM, Gristina AG: Methylmethacrylate as an adjunct in internal fixation of pathological fractures: Experience with three hundred and seventy-five cases. J Bone Joint Surg Am 1976;58:1047-1054.Sun S, Lang EV: Bone metastases from renal cell carcinoma: Preoperative embolization. J Vasc Interv Radiol 1998;9:263-269.Katzner M, Schvingt E: Operative treatment of bone metastases secondary to renal carcinoma: Basic research and treatment of renal cell carcinoma metastasis. Prog Clin Biol Res EORTC 1990;348:151-168.
Question 1519
Topic: 10. Pathology and Oncology
A 21-year-old man has had right groin pain for the past year. A radiograph, CT scan, MRI scans, and a biopsy specimen are shown in Figures 50a through 50e. What is the most likely diagnosis?
Correct Answer & Explanation
. Chondrosarcoma
Explanation
DISCUSSION: The pathology demonstrates a very cellular chondroid matrix with multinucleated forms, atypia, and myxomatous regions. This is most consistent with a myxoid chondrosarcoma. The radiograph shows a well-circumscribed lesion in the superior and medial aspect of the right acetabulum. The CT and MRI scans confirm these same findings with no evidence of matrix mineralization or significant surrounding edema. Unfortunately, in this location with this appearance, the radiographic differential diagnosis includes all the diagnoses listed.REFERENCES: Terek RM: Recent advances in the basic science of chondrosarcoma. Orthop Clin North Am 2006;37:9-14.Donati D, El Ghoneimy A, Bertoni F, et al: Surgical treatment and outcome of conventional pelvic chondrosarcoma. J Bone Joint Surg Br 2005;87:1527-1530.Pring ME, Weber KL, Unni KK, et al: Chondrosarcoma of the pelvis: A review of sixty-four cases. J Bone Joint Surg Am 2001;83:1630-1642.
Question 1520
Topic: 10. Pathology and Oncology
What clinical finding is associated with the least favorable prognosis in an adolescent patient who has been diagnosed with a high-grade osteosarcoma of the distal femur?
Correct Answer & Explanation
. A solitary peripheral lung metastasis
Explanation
DISCUSSION: The presence of synchronous bone disease in young patients carries a dismal prognosis, one that is even worse than the presence of resectable pulmonary metastasis. Many osteosarcomas cross the physis; therefore, this has not been shown to be of prognostic importance. Similarly, the presence of the soft-tissue mass has less prognostic significance.REFERENCE: Mirra JM: Bone Tumors: Clinical, Radiologic, and Pathologic Correlation. Philadelphia, PA, Lea and Febiger, 1989, pp 344-350.
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