Purpose: Liposarcoma is a mesenchymal neoplasm and comprise 20%–30% of all soft tissue sarcomas, accounting for 1% of all malignancies. This study documented the clinical manifestation and oncological outcomes of dedifferentiated liposarcoma (DDLPS). Materials and Methods: Eleven patients were diagnosed and treated for DDLPS between January 2013 and December 2020. The age, gender, symptom onset, tumor location, magnetic resonance images, surgical margin, and pathologic diagnosis of the identified cohort were reviewed. The time to local recurrence or metastasis, follow-up duration, and the patients’ final status were analyzed. Results: The patients comprised seven male and four female patients with a mean age of 59 years (43–73 years). The tumor location was in the thigh in five, inguinal in two, upper arm in two, forearm in one, and popliteal in one. The average tumor diameter was 12 cm (3.5–27.0 cm). At the time of diagnosis, one patient was American Joint Committee on Cancer stage IB, two were II, four were IIIA, and four were IIIB. Local recurrence occurred in four, and distant metastasis occurred in five. The five-year overall survival of patients with DDLPS was 54.5±17.6%, and four died due to disease progression. Conclusion Primary DDLPS in the extremities is a subtype of liposarcoma with a poorer prognosis than well-differentiated liposarcoma and myxoid liposarcoma.

Purpose: The purpose of this study was to evaluate the clinical characteristics and treatment outcomes of alveolar soft part sarcoma (ASPS) of the extremities and trunk and investigate the prognostic factors. Materials and Methods: Forty patients presenting with ASPS in the extremities or trunk between 2001 and 2021 were reviewed retrospectively. We evaluated the clinical manifestations at presentation, local recurrence, and metastasis after treatment. The survival rates and prognostic factors affecting survival were analyzed. Only patients who were followed up for more than one year were included in the study. The mean follow-up time was 58 months (range, 12–120). Results: The average age of the patients was 26 years (range, 12–54) and the primary tumor developed mainly in the thigh (23 patients, 57.5%). The average size of the tumor was 8.7 cm and metastasis at presentation was seen in 28 (70%) patients. The overall survival rates at five-years and 10-years were 53.7% and 34.5%, respectively. Metastasis at presentation was related to poor survival (p=0.001). Conclusion ASPS in the extremities or trunk present with a high rate of metastasis and patients with metastasis showed poorer survival.In the future, further efforts to develop novel therapies like target therapy or immunotherapy for the treatment of metastatic patients are warranted.

Purpose: Giant cell tumor (GCT) of the proximal femur is relatively rare, with only a few case series reported thus far. This study aimed to evaluate the clinical outcomes of GCT of the proximal femur treated with intralesional curettage and expand the understanding of their characteristics and treatment considerations. Materials and Methods: Fifteen cases treated with curettage for GCT of the proximal femur between 2007 and 2020 were reviewed. The median follow-up was 46 months (25–150 months). There were 10 males and 5 females with a median age of 26 years (17–71 years). After curettage, the bone defect was filled with either an allograft (7 cases) or bone cement (8 cases). Results: The postoperative complications were local recurrences in three cases (20.0%), including malignant transformation in one case and a femur neck fracture in one case (6.7%) following curettage and strut allograft. Among the 15 cases, 13 (86.7%) retained their native joint at the last follow-up. No patients developed degenerative changes or osteonecrosis. Conclusion The results of proximal femoral GCT with curettage were acceptable despite local recurrences in three cases (20.0%), and femur neck fracture in one case. An appropriate surgical approach and reconstruction according to the extent of the lesion are necessary for successful treatment.

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Purpose: This study examined the prevalence of osteoarthritis of the knee after curettage and polymethylmethacrylate (PMMA) application for giant cell tumor of the bone (GCTB) and factors affecting the development of osteoarthritis of the knee. Materials and Methods: Fifty-five patients with GCTB of the distal femur who were treated with curettage and PMMA filling between June 2001 and June 2016 were reviewed retrospectively. The development of osteoarthritis of the knee, as Kellgren–Lawrence grade 3 or 4, was determined by radiography of the latest follow-up data. This study evaluated the influence of the factors on the development of osteoarthritic changes. Only patients followed up for more than five years were included and the median follow-up was 77 months (range, 60–237 months). Results: Osteoarthritis of the knee was observed in 10 patients (18%) of whom three showed preoperative arthritic changes and did not progress. Seven (13%) patients experienced progression of the arthritic changes after surgery at a median of five years (range, 4–12 years). On the other hand, none of them received total knee arthroplasty. Among seven patients who showed progression of arthritis, four patients presented with a pathologic fracture initially and showed arthritic changes at a median of 4.5 years after surgery. The other three patients showed arthritic changes after ten years or more. Pathologic fractures (p=0.0001) and subchondral bone involvement (p=0.011) were significant risk factors for the development of osteoarthritis. Conclusion The incidence of development of osteoarthritis of the knee after curettage and PMMA application at distal femoral GCTB was 13%, but none of these patients received further surgery, such as total knee arthroplasty. The pathologic fracture and subchondral bone involvement are risk factors for arthritic changes in the midterm follow-up.

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.

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.
Chondrosarcoma ; Cohort Studies ; Curettage ; Diagnosis ; Disease Progression ; Female ; Femur ; Fibrosarcoma ; Follow-Up Studies ; Fractures, Spontaneous ; Humans ; Lung ; Magnetic Resonance Imaging ; Male ; Metatarsal Bones ; Neoplasm Metastasis ; Osteosarcoma ; Pathology ; Pelvis ; Prognosis ; Recurrence ; Sarcoma

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.
Cellular Structures ; Extremities ; Follow-Up Studies ; Humans ; Liposarcoma ; Liposarcoma, Myxoid ; Lower Extremity ; Neoplasm Metastasis ; Prognosis ; Recurrence ; Retrospective Studies ; Survival Rate

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.
Chondrosarcoma ; Fractures, Bone ; Humans ; Neoplasm Metastasis ; Osteosarcoma ; Recurrence ; Retrospective Studies ; Tibia ; Transplants