The Clinical Outcome of Extraskeletal Myxoid Chondrosarcoma / 대한정형외과학회잡지

Purpose@#Extraskeletal myxoid chondrosarcoma (EMC) is an extremely rare malignant mesenchymal neoplasm, accounting for less than 3% of soft tissue sarcomas. This sarcoma is usually characterized by its indolent course. This study examined the clinical manifestations and oncologic outcomes of EMC. @*Materials and Methods@#Seventeen patients diagnosed and treated for EMC between January 2008 and December 2018 were enrolled in this study. The cohort was then reviewed regarding age, gender, symptom onset, tumor location, magnetic resonance images, surgical margin, and pathologic diagnosis. The time to local recurrence and metastasis, follow-up duration, and the patients’ final status were analyzed. @*Results@#The patients were comprised of 10 males and seven female patients with a mean age of 54 (range, 31–79). The tumor location was the buttock in five, thigh in four, knee in three, foot in three, shoulder in one, and back in one. The average tumor diameter was 11.5 cm (range, 2.2–23.2 cm). At the time of diagnosis, five patients were American Joint Committee on Cancer stage II; three were IIIA; three were IIIB; six were IV. Local recurrence occurred in 12 cases, and distant metastasis occurred in 15 cases. The five-year overall survival of the patients with EMC was 73%±17%, and two patients died of the disease. @*Conclusion@#Despite the high rate of local recurrence and distant metastasis, the long-term survival rate in patients with EMC is quite high because of its indolent characteristics.

Myxoid Liposarcoma: A Single Institute Experience / 대한정형외과학회잡지

PURPOSE: This study assessed the treatment outcomes of myxoid liposarcoma in the extremities and investigate the prognostic factors. MATERIALS AND METHODS: A total of 91 patients with myxoid liposarcoma (83 primary, 8 recurrent) between 2001 and 2015 were reviewed retrospectively. The local recurrence and metastasis after treatment were examined. The survival rates and prognostic factors affecting the survival were investigated. The mean follow-up was 84 months (range, 5–196 months). RESULTS: The overall survival rates at 5-yr and 10-yr were 82% and 74%, respectively. The tumor size (p=0.04), round cell component (p<0.0001), grade (p=0.0002), and local recurrence (p=0.006) affected survival in primary patients. Extrapulmonary metastases were observed in 75.0% (18/24) of metastatic patients and the mean post metastasis survival was 26 months (range, 2–72 months). CONCLUSION: Myxoid liposarcoma developed mainly at the lower extremities. The tumor size, grade, component of round cells, and local recurrence were associated with the prognosis. The unique feature of extrapulmonary metastasis in myxoid liposarcoma should be noted in the treatment and follow-up.

The Clinical Outcome of Dedifferentiated Chondrosarcoma / 대한정형외과학회잡지

PURPOSE: A dedifferentiated chondrosarcoma is a rare lethal tumor characterized by a low grade chondrosarcoma juxtaposed with a high grade dedifferentiated sarcoma, such as osteosarcoma, fibrosarcoma. The aim of our study was to document the clinical manifestation and oncologic outcomes of a dedifferentiated chondrosarcoma. MATERIALS AND METHODS: This study identified 11 patients who were diagnosed and treated for dedifferentiated chondrosarcoma between January 2007 and December 2016. The identified cohort was then reviewed regarding age, sex, symptom onset, tumor location, magnetic resonance imagings (MRIs), surgical margin, and pathologic diagnosis. The time to local recurrence and/or metastasis, follow-up duration, and the patients' final status were analyzed. RESULTS: The patients were comprised of 7 males and 4 females with a mean age of 54 years (range, 33–80 years). The location of the tumor was in the femur in 6 cases, pelvis in 4 cases, and metatarsal in 1 case. The average tumor diameter was 12.7 cm (range, 6.0–26.1 cm). At the time of diagnosis, 2 patients showed pathologic fracture; 1 patient was Enecking stage IIA, 9 patients were stage IIB, and 1 patient was stage III. Eight patients were classified as a primary dedifferentiated chondrosarcoma and 3 patients were secondary. One of the primary lesions was misinterpreted initially as a low grade chondroid lesion by MRI and underwent curettage. Local recurrence occurred in 8 cases and distant metastasis occurred in 10 cases with a mean duration of 8 months (range, 2–23 months) and 7 months (range, 1–32 months), respectively. The three-year overall survival of patients with dedifferentiated chondrosarcoma was 18%, and 10 patients died due to disease progression. CONCLUSION: Dedifferentiated chondrosarcoma developed lung metastases in the early period of the clinical courses and the prognosis was dismal.

The Results of Hemicortical Resection for Malignant Bone Tumor / 대한정형외과학회잡지

PURPOSE: Hemicortical resection may be applied to bone tumors arising at the bone surface or of eccentric location due to minimal medullary involvement. The purpose of this study was to evaluate the results of hemicortical resection for malignant bone tumors. MATERIALS AND METHODS: We retrospectively reviewed 18 patients who were treated with hemicortical resection between 2005 and 2014. The study included 10 patients with parosteal osteosarcoma, 5 patients with osteosarcoma, 2 patients with periosteal chondrosarcoma, and 1 patient with chondrosarcoma, who were followed-up for a mean duration of 61 months (24–125 months). We evaluated 1) the oncologic outcome (recurrence, metastasis), 2) the rate of bony union, and 3) complications, such as fracture or infection, after hemicortical resection and reconstruction. RESULTS: There were local recurrences in 3 parosteal osteosarcoma patients (16.7%). After subsequent re-excision for recurrence, one patient died of metastasis. The defect after hemicortical resection was reconstructed by bone graft in 15 patients and the grafts were removed for infection in 2 patients. Bone grafts were united in 12 (92.3%) out of 13 patients at 8 months (5–13 months) after reconstruction on average. Host bone fractures occurred in 2 patients (11.1%); infection developed in 3 patients (16.7%), who received hemicondylar resection for osteosarcoma in proximal tibia. CONCLUSION: Hemicortical resection for eccentric tumors or small tumors showed good clinical results. There is relatively a high risk of infection in the lesion of proximal tibia.

Clear Cell Chondrosarcoma Mimicking Benign Bone Tumors / 대한정형외과학회잡지

PURPOSE: Clear cell chondrosarcoma may have a benign appearance even on a magnetic resonance imaging (MRI). Hence, it can be confused with benign bone tumors, such as a giant cell tumor or chondroblastoma. The aim of our study was to document the doctorassociated diagnostic errors in patients with clear cell chondrosarcoma and oncologic outcomes of these lesions, which were misdiagnosed as benign bone tumors. MATERIALS AND METHODS: We identified 10 patients who were diagnosed with and treated for clear cell chondrosarcoma between January 1996 and December 2014. One patient was excluded due to insufficient clinical data. We then reviewed their data regarding age, gender, symptom onset, tumor location, initial imaging diagnosis, and associated previous treatment. We examined the errors of surgeons and pathologists with respect to patient and tumor characteristics. We also analyzed treatment delay, time to local recurrence, metastasis, follow-up duration, and the oncologic outcome. RESULTS: The initial presumptive diagnosis based on MRIs for all 9 patients was benign bone tumor. Among 8 patients who underwent inappropriate procedure, half of them were diagnosed as clear cell chondrosarcoma immediately after the curettage. As for the remaining 4 patients, the surgeon did not send any tissue samples to a pathologist for a definite diagnosis in three patients and a pathologist made an incorrect diagnosis in one patient. We performed an appropriate surgery on all patients with a wide surgical margin. The average treatment delay was 27 months (range, 0–127 months), and the average follow-up duration was 65 months (range, 13–164 months). One patient had local recurrence after 12 months. Metastatic disease developed in 2 patients with a median time to definitive treatment of 24 months (12–37 months). Ten-year overall survival of patients with clear cell chondrosarcoma was 78%, and two patients died due to disease progression. CONCLUSION: Misdiagnosis of clear cell chondrosacroma as a benign bone tumor is not uncommon, even for experienced orthopaedic oncologists, resulting in definite curative surgery without biopsy. An inappropriate primary treatment may increase the risk of local recurrence and metastasis. Therefore, a proper subsequent surgery is mandatory for patients with clear cell chondrosarcoma who received inadvertent curettage.

The Optimal Surgical Approach and Complications in Resecting Osteochondroma around the Lesser Trochanter / 대한정형외과학회잡지

PURPOSE: Surgical risks associated with the resection of osteochondroma around the proximal tibia and fibula, as well as the proximal humerus have been well established; however, the clinical presentation and optimal surgical approach for osteochondroma around the lesser trochanter have not been fully addressed. MATERIALS AND METHODS: Thirteen patients with osteochondroma around the lesser trochanter underwent resection. We described the chief complaint, duration of symptom, location of the tumor, mass protrusion pattern on axial computed tomography image, tumor volume, surgical approach, iliopsoas tendon integrity after resection, and complication according to the each surgical approach. RESULTS: Pain on walking or exercise was the chief complaint in 7 patients, and numbness and radiating pain in 6 patients. The average duration of symptom was 19 months (2–72 months). The surgical approach for 5 tumors that protruded postero-laterally was postero-lateral (n=3), anterior (n=1), and medial (n=1). All 4 patients with antero-medially protruding tumor underwent the anterior approach. Two patients with both antero-medially and postero-laterally protruding tumor received the medial and anterior approach, respectively. Two patients who underwent medial approach for postero-laterally protruded tumor showed extensive cortical defect after resection. One patient who received the anterior approach to resect a large postero-laterally protruded tumor developed complete sciatic nerve palsy, which was recovered 6 months after re-exploration. CONCLUSION: For large osteochondromas with posterior protrusion, we should not underestimate the probability of sciatic nerve compression. When regarding the optimal surgical approach, the medial one is best suitable for small tumors, while the anterior approach is good for antero-medial or femur neck tumor. For postero-laterally protruded large tumors, posterior approach may minimize the risk of sciatic nerve palsy.

Locking Mechanism Failure after Distal Femoral Reconstruction with Modular Universal Tumor and Revision System (MUTARS) Tumor Prosthesis / 대한정형외과학회잡지

PURPOSE: We have used Modular Universal Tumor and Revision System (MUTARS) tumor prosthesis to reconstruct segmental resection defect of the distal femur. The purpose of this study was to evaluate the incidence and pattern of locking mechanism breakage and its correlation with other clinical variables. MATERIALS AND METHODS: We retrospectively reviewed 94 patients who were followed-up for more than one year after tumor prosthesis replacement (MUTARS) between 2008 and 2013. We examined the incidence and timing of locking mechanism (PEEK-OPTIMA) failure. We also evaluated the clinical characteristics of patients experiencing locking mechanism failure and compared them with those of other patients. RESULTS: At a mean follow-up of 55 months, we observed locking mechanism failure in 10 of 94 patients (10.6%). The mean age of patients with locking mechanism failure was 29 years (range, 13-54 years); the mean weight and height were 169 cm (range, 151-181 cm) and 67 kg (range, 53-89 kg), respectively. The mean body mass index was 23.5 kg/m² (range, 20.5-29.4 kg/m²). The median time interval between replacement and locking mechanism failure was 26.5 months (range, 12-72 months). The mean body weight of patients with failure was higher than that of patients without failure (p=0.019). CONCLUSION: The incidence of locking mechanism (PEEK-OPTIMA) failure after distal femoral reconstruction with MUTARS was 11%, and there was a correlation between failure and body weight of patients. Advancements in the design and material of locking mechanisms are warranted to reduce the complication.

Comparison of Pasteurized Autograft-Prosthesis Composite Reconstruction and Resection Hip Arthroplasty for Periacetabular Tumors

BACKGROUND: Because of the high complication rate of anatomical reconstruction after periacetabular resection, the strategy of resection alone has been revisited. However, in terms of complications and functional outcome, whether resection hip arthroplasty (RHA) shows a superior result to that of pelvic ring reconstruction remains controversial. METHODS: We compared 24 RHAs and 16 pasteurized autograft-prosthesis composite (PPC) reconstructions regarding the complication rates, operative time, blood loss, and functional outcome. RESULTS: Compared to 16 PPC hips, 24 RHA hips showed lower major and minor complication rates (p < 0.001), shorter surgical time (p < 0.001), and superior Musculoskeletal Tumor Society scores (p < 0.001). Of the 24 RHA hips, bony neo-acetabulum was identified in 7 on computed tomography and partial neo-acetabulum in 9; the remaining 8 had no bony acetabular structure. The average time to bony neo-acetabulum formation was 7 months (range, 4 to 13 months). CONCLUSIONS: RHA for periacetabular tumors can be an excellent alternative to anatomical reconstruction. It offers short surgical time, low complication rates, and functional results comparable to those of other reconstruction methods. However, this procedure is indicated for patients who can accept some limb shortening, and a tumor should be confined to the periacetabular area.

The Clinical Outcome of Soft Tissue Solitary Fibrous Tumor / 대한정형외과학회잡지

PURPOSE: Solitary fibrous tumors (SFT) represent a rare entity of soft tissue tumors which are exclusively located in the thoracic cavity as pleural fibrous tumors. Extrathoracic SFT in the soft tissues are very rare. We analyzed the oncologic outcome of the soft tissue SFT. MATERIALS AND METHODS: Between January 2009 and December 2014, we treated 6 soft tissue SFT cases. Patients' clinical data, magnetic resonance imagings and pathologic findings were reviewed. RESULTS: The patients included two women and four men. The average age of the patients was 45 years (range, 32-56 years). The mean tumor size is 7.2 cm (range, 3.5-13.0 cm). One patient received wide excision of the tumor and remaining 5 patients marginal excision. After the excision, pathologic report confirmed that 4 patients showed margin positive. However, no patient received further surgery or adjuvant treatments. After the immunohistochemistry, 2 out of 6 patients identified as malignant soft tissue SFT. The mean follow-up period was 25.8 months (range, 6-66 months). Although 4 patients revealed margin positivity, no subsequent local recurrence or distant metastasis was observed. CONCLUSION: Since the SFT are categorized as intermediated biological potential with a low risk of metastasis and recurrence, marginal excision can be a one of the surgical options for these tumors which are located adjacent to vital structures. However, close observation is needed because local recurrence can be significantly higher the patients with positive resection margins.

Surgical and Oncological Outcome of Pelvis Bone Tumor Patients with Type III Internal Hemipelvectomy / 대한정형외과학회잡지

PURPOSE: It is generally accepted that bony reconstruction after type III (pubic) internal pelvectomy is not necessary. However, technical problems in type III resection, functional outcome according to the extent of resection, and the usefulness of synthetic material to decrease the risk of hernia has not been well addressed. MATERIALS AND METHODS: Fifteen patients who underwent type III internal pelvectomy were extracted and the pathologic diagnosis, Enneking's stage, location of tumor and size, operation time, amount of transfusion, surgical margin, local recurrence, distant metastasis, and functional outcomes were analyzed according to the extent of resection. RESULTS: Pathologic diagnosis was chondrosarcoma in 9, Ewing's sarcoma in 3, metastatic carcinoma in 2, and osteosarcoma in 1 patient. There were 4 patients with local recurrence and one with concomitant lung metastasis. Average Musculoskeletal Tumor Society functional score was 26.7. According to the extent of resection, functional score of 7 cases with unilateral both rami (6) or ischium (1) resection was 26, 4 cases with unilateral both rami and partial contralateral pubic ramus resection was 25, and 4 cases with unilateral both rami including ischium was 24. Two patients had tumor related complication. One patient with a huge intrapelvic tumor aroused at the symphysis pubis showed urethral invasion at presentation, therefore, urethral resection and permanent suprapubic cystostomy was inevitable. The other patient with bilateral pubic ramus involvement by tumor showed caudal displacement of the uterus after pregnancy (4 years after primary resection). She underwent Caesearian section for delivery. CONCLUSION: Regardless of the extent of pubic bone resection, functional outcome was similar. The risk of abdominal or pelvic organ hernia was minimal even without the use of artificial material for soft tissue reconstruction; however, when the extent of resection crosses the symphysis pubis, selective application of an additional procedure to reinforce the pelvic floor may be considered.

Giant Cell-Rich Osteosarcoma: A Tumor Simulating Borderline Lesion / 대한정형외과학회잡지

PURPOSE: Giantcell-rich osteosarcoma (GCRO) is a rare subtype of osteosarcoma. We reviewed; 1) radiological finding of GCRO and clinical impression-related diagnostic workup at referral center, 2) diagnostic delay until a proper diagnosis is made, 3) impact of diagnostic delay on the oncologic outcome. MATERIALS AND METHODS: We reviewed 17 patients with GCRO. We investigated the plain radiographic finding, tumor size and location, presence of pathologic fracture, clinical impression and pathological diagnosis at referral center, diagnostic delay, definitive treatment, local recurrence, metastasis, and survival rate. RESULTS: Eleven cases (64.7%) showed a plain radiographically, purely osteolytic pattern while 6 cases (35.3%) showed mixed osteolytic and sclerotic lesion. Diagnosis at primary center was osteosarcoma in 7 (41.2%), giant cell tumor in 7 (41.2%), and benign bone tumor in 3 (17.6%). Six patients (35.3%) experienced diagnostic delay. Mean diagnostic delay was 3.1 months (1 to 8). At final follow-up 5-year actuarial survival rate of 17 patients was 65%+/-25%. Although 11 patients without diagnostic delay showed a tendency of high survival over 6 patients with diagnostic problem, there was no statistical significance (p=0.14). CONCLUSION: GCRO is a rare subtype of osteosarcoma simulating giant cell tumor both pathologically and radiologically. Careful diagnostic approach is required in order not to misdiagnose this malignant tumor.

Diagnosis, Treatment and Prognosis of Low Grade Central Osteosarcoma / 대한골관절종양학회지

PURPOSE: We analyzed the diagnosis and the treatment outcomes of patients with central low grade osteosarcoma. MATERIALS AND METHODS: We retrospectively reviewed 16 patients with central low grade osteosarcoma were treated at out institution between 1994 and 2011. RESULTS: There were 4 men and 12 women with mean age of 26 years. Eleven patients were correctly diagnosed but 5 patients were misdiagnosed as osteoid osteoma, non ossifying fibroma, aneurysmal bone cyst, desmoplastic fibroma. 15 patients finally received wide margin en bloc excision and one of them treated under neoadjuvant chemotherapy. Final survival status was continuous disease free in 14 and 1 patient died of renal cell cancer. Remaining 1 with multifocal lesions is alive with disease for 7 years only treated radiation therapy on residual tumors. Nine (56%) of 16 tumors showed extra-osseous extension of tumor (56%) and 1 of them showed extra-compartmental tumors. CONCLUSION: The diagnosis of central low grade osteosarcoma is challenging, however, considering of the clinical suspicion, the typical findings of radiologic and pathologic features, proper diagnosis is needed. This tumor should be treated with wide excision, even after an intralesional excision, to avoid local recurrence or transformation to higher histologic grade.

Soft Tissue Malignant Myoepithelioma in the Extremities / 대한골관절종양학회지

PURPOSE: We report the diagnosis, treatment outcomes and prognosis of the patients with soft tissue malignant myoepithelioma in the extremities. MATERIALS AND METHODS: We retrospectively reviewed 6 patients with soft tissue malignant myoepithelioma in the extremities who were treated at our institution between 2008 and 2014. Two patients received unplanned excision at another hospital and remaining 4 patients underwent the biopsy procedures and received wide excision at our hospital. RESULTS: There were 3 men and 3 women with mean age of 41 (33-54) years. The average follow up was 28 (9-45) months. Among the 6 patients, only 4 patients underwent biopsy procedures under the impression of malignant soft tissue sarcoma. Surgical margins for these 4 patients were negative. Two patients who had unplanned excision received another re-excision and one of them showed no residual tumor in the resected specimen. Local recurrences were developed in all patients and distant metastasis in 4 patients. All 4 patients who developed distant metastasis died due to disease progression. Among the 2 patients who developed local recurrence only, one patient has another local recurrence after re-operation and remaining one patient is no evidence of disease for 2 years after resection of locally recurred mass. CONCLUSION: Soft tissue malignant myoepithelioma in the extremities is a rare disease and shows an aggressive behavior. Appropriate biopsy under the impression of soft tissue malignancy is necessary and complete surgical resection with wide margins is the recommended treatment of choice.

Infectious Spondylitis Mimicking Osteoporotic Vertebral Compression Fractures: Report of Two Cases

STUDY DESIGN: Case study of two cases. OBJECTIVES: The aim of our study is to describe the rare MR imaging patterns of infectious spondylitis. SUMMARY OF LITERATURE REVIEW: It is generally accepted that the intravertebral cleft sign is not shown in cases of infection or malignancy, and thus, its recognition can obviate unnecessary imaging or biopsy because of its benign significance. MATERIALS AND METHODS: Two patients are presented who developed worsening back pain after a minor trauma. Preoperative MR images of these patients showed intravertebral fluid and benign vertebral compression fractures. Anterior decompression and fusion were done and the bacteria isolated from the intraoperative cultures were Listeria monocytogenes and Mycobacterium tuberculosis, respectively. RESULTS: After 2 years of follow-up, the patients were free of pain, without signs of infection, and showed correct fusion. CONCLUSIONS: MR findings in infectious spondylitis may simulate the patterns of osteoporotic VCFs.

Rosai-Dorfman Disease as a Solitary Lesion of the Tibia / 대한골관절종양학회지

Rosai-Dorfman disease (RDD) is an idiopathic histioproliferative disorder of lymph node and extranodal site. Bone involvement is very rare. We report a case of extranodal RDD of the tibia in 32-year old male. The patient presented with pain with no evidence of lymphadenopathy. Clinico-radiologic diagnosis was metastatic carcinoma or Langerhans cell histiocytosis, but, histopathologic examination confirmed the diagnosis with RDD. We performed curettage on the osteolytic lesion of tibia. In South Korea, there was no report about RDD of the extremity and we want to report this case with review of the literature.

Plain Radiologic Findings and Chronological Changes of Incipient Phase Osteosarcoma Overlooked by Primary Physicians

BACKGROUND: We assessed the plain radiographic characteristics of 10 cases of osteosarcomas during the initial painful period that had been overlooked by a primary physician. In addition, we evaluated chronologic changes in radiographic findings from initial symptomatic period to the time of accurate diagnosis. METHODS: The clinical records were reviewed for clinical parameters including age, sex, location, presenting symptoms, initial diagnosis, duration from initial symptoms to definite diagnosis, and initial and follow-up plain radiographic findings of the lesion. RESULTS: Initial clinical diagnoses included a sprain in 6, growing pain in 2, stress fracture in 1, and infection in 1 patient. Initial plain radiographic findings were trabecular destruction (100%), cortical disruption (60%), periosteal reaction (60%), and soft tissue mass (10%). Intramedullary matrix changes were osteosclerosis in 6 and osteolysis in 4 patients. On progression, 4 cases with minimal sclerosis changed to osteoblastic lesion in 3 patients and osteolytic lesion in 1. Four cases with faint osteolytic foci transformed into osteolytic lesion in 3 and mixed pattern in 1. CONCLUSIONS: Notable plain radiologic findings of incipient-stage osteosarcoma include trabecular disruption along with faint osteosclerosis or osteolysis. In symptomatic patients with trabecular destruction, additional imaging study including magnetic resonance imaging should be performed to exclude osteosarcoma in the incipient phase, even without radiologic findings suggesting malignant tumor, such as cortical destruction or periosteal reaction.

Role of Surgical Margin on Local Recurrence in High Risk Extremity Osteosarcoma: A Case-Controlled Study

BACKGROUND: The relationship between surgical margin and local recurrence (LR) in osteosarcoma patients with poor responses to chemotherapy is unclear. Moreover, the incidences of LR according to three different resection planes (bone, soft tissue, and perineurovascular) are not commonly known. METHODS: We evaluated the incidence of LR in three areas. To assess whether there is a role of surgical margin on LR in patients resistant to preoperative chemotherapy, we designed a case (35 patients with LR) and control (70 patients without LR) study. Controls were matched for age, location, initial tumor volume, and tumor volume change during preoperative chemotherapy. RESULTS: LR occurred at the soft tissues in 18 cases (51.4%), at the perineurovascular tissues in 11 cases (31.4%), and at the bones in six cases (17.2%). The proportion of inadequate perineurovascular margin was higher in the case group than in the control group (p = 0.01). Within case-control group (105 patients), a correlation between each margin status and LR at corresponding area was found in the bone (p < 0.001) and perineurovascular area (p = 0.001). CONCLUSIONS: LR is most common in soft tissues. In patients showing similar unfavorable responses to chemotherapy, the losses of perineurovascular fat plane on preoperative magnetic resonance imaging may be a valuable finding in predicting LR.

Rupture of a Brachial Artery Caused by a Humeral Osteochondroma / 대한정형외과학회잡지

Pseudoaneurysm resulting from vascular impingement by an osteochondroma is extremely rare. The authors report on the case of a 16-year-old male who had a brachial artery pseudoaneurysm and vessel rupture associated with a humeral osteochondroma. This case suggests that pseudoaneurysm should be considered for the differential diagnosis in patients with soft tissue masses and a cuspidal osteochondroma located near the neurovascular bundle and recommends Doppler sonography or angiography.

Inflammatory Myofibroblastic Tumor of Extremities / 대한골관절종양학회지

PURPOSE: We analyzed the oncologic characteristics and outcome of patients with inflammatory myofibroblastic tumor of extremities. MATERIALS AND METHODS: Among the soft tissue tumor patients who were treated between 1999 and 2012, 5 patients who were pathologically confirmed as the inflammatory myofibroblastic tumor of extremities were analyzed retrospectively. RESULTS: There were 1 man and 4 women with mean age of 44 years (37-55 years). The average follow up was 34.6 months (8-87 months). All patients underwent surgical treatment. Only 1 patient had wide resection margin and remaining 4 had marginal (3) or intralesional (1) resection margin. All of 4 patients without wide resection margin developed local recurrence at 10.3 months (8-19 months). Malignant transformation to fibrosarcoma was occurred in 2 patients who developed local recurrence, and 1 patient developed multiple metastases to lung, liver and lymph nodes and expired at 37 months. Three of 5 patients had tumor location abutted to or invasion to major arteries and 1 patient had tumor invading sciatic nerve. CONCLUSION: It is observed that inflammatory myofibroblastic tumor of extremities is usually located near the major neurovascular structure. Wide resection should be considered as the initial surgical treatment because this tumor showed a high local recurrence rate and possibility of malignant transformation.

Clinical Outcome of Parosteal Osteosarcoma / 대한골관절종양학회지

PURPOSE: The purpose of this study was to evaluate the oncologic outcomes of parosteal osteosarcoma (POS) and to ascertain the fates of patients after local recurrence (LR). MATERIALS AND METHODS: The authors retrospectively reviewed 22 POS patients with an average follow-up of 114 months (range: 36-235 months). Seven of the 22 patients were referred after LR. There were 17 Stage IB and 5 Stage IIB (G2, 2; dedifferentiation, 3). Tumors were located in the femur (11) and in other locations (11). Initial surgical margins were wide in 10, marginal in 5, and intralesional in 7. Correlations between clinico-pathologic variables and LR and clinical courses after LR were evaluated. RESULTS: The 10-year overall survival rate was 85.7%. Three (14%) patients developed distant metastasis and all of them succumbed to the disease. Nine (41%) patients developed LR. Tumor location, resection type, and surgical margin were found to be correlated with LR. At final follow-up, 7 of the 9 patients that experienced local failure achieved no evidence of disease. CONCLUSION: A substantial risk of misdiagnosis exists, especially for POS in other than a femoral location. Recurrent tumor re-excision is possible in most cases; however, patients with an aggressive recurrence pattern deserve special attention.