High-quality expert annotations enhance artificial intelligence model accuracy for osteosarcoma X-ray diagnosis.

Primary malignant bone tumors, such as osteosarcoma, significantly affect the pediatric and young adult populations, necessitating early diagnosis for effective treatment. This study developed a high-performance artificial intelligence (AI) model to detect osteosarcoma from X-ray images using highly accurate annotated data to improve diagnostic accuracy at initial consultations. Traditional models trained on unannotated data have shown limited success, with sensitivities of approximately 60%-70%. In contrast, our model used a data-centric approach with annotations from an experienced oncologist, achieving a sensitivity of 95.52%, specificity of 96.21%, and an area under the curve of 0.989. The model was trained using 468 X-ray images from 31 osteosarcoma cases and 378 normal knee images with a strategy to maximize diversity in the training and validation sets. It was evaluated using an independent dataset of 268 osteosarcoma and 554 normal knee images to ensure generalizability. By applying the U-net architecture and advanced image processing techniques such as renormalization and affine transformations, our AI model outperforms existing models, reducing missed diagnoses and enhancing patient outcomes by facilitating earlier treatment. This study highlights the importance of high-quality training data and advocates a shift towards data-centric AI development in medical imaging. These insights can be extended to other rare cancers and diseases, underscoring the potential of AI in transforming diagnostic processes in oncology. The integration of this AI model into clinical workflows could support physicians in early osteosarcoma detection, thereby improving diagnostic accuracy and patient care.

Comparison of clinical outcome between surgical treatment and particle beam therapy for pelvic bone sarcomas: A retrospective multicenter study in Japan.

BACKGROUND: Few studies have compared the clinical outcomes of patients with pelvic bone sarcomas treated surgically and those treated with particle beam therapy. This is a multicenter retrospective cohort study which compared the clinical outcomes of patients with pelvic bone sarcoma who underwent surgical treatment and particle beam therapy in Japan. METHODS: A total of 116 patients with pelvic bone sarcoma treated at 19 specialized sarcoma centers in Japan were included in this study. Fifty-seven patients underwent surgery (surgery group), and 59 patients underwent particle beam therapy (particle beam group; carbon-ion radiotherapy: 55 patients, proton: four patients). RESULTS: The median age at primary tumor diagnosis was 52 years in the surgery group and 66 years in the particle beam group (P < 0.001), and the median tumor size was 9 cm in the surgery group and 8 cm in the particle beam group (P = 0.091). Overall survival (OS), local control (LC), and metastasis-free survival (MFS) rates were evaluated using the Kaplan-Meier method and compared among 116 patients with bone sarcoma (surgery group, 57 patients; particle beam group, 59 patients). After propensity score matching, the 3-year OS, LC, and MFS rates were 82.9% (95% confidence interval [CI], 60.5-93.2%), 66.0% (95% CI, 43.3-81.3%), and 78.4% (95% CI, 55.5-90.5%), respectively, in the surgery group and 64.9% (95% CI, 41.7-80.8%), 86.4% (95% CI, 63.3-95.4%), and 62.6% (95% CI, 38.5-79.4%), respectively, in the particle beam group. In chordoma patients, only surgery was significantly correlated with worse LC in the univariate analysis. CONCLUSIONS: The groups had no significant differences in the OS, LC, and MFS rates. Among the patients with chordomas, the 3-year LC rate in the particle beam group was significantly higher than in the surgery group.

Secondary osteosarcoma associated with osteofibrous dysplasia: a case report.

Secondary osteosarcoma is a rare complication of primary malignancies and benign bone lesions. There are various types of diseases that cause secondary osteosarcoma. A 15-year-old male presented at our medical center complaining of pain and redness in the right lower leg. He had been diagnosed with osteofibrous dysplasia in the right tibia when he was 2 years old and since then had been followed up. Although he had a pathological fracture of the right tibia at the age of 7, his fracture healed with a plaster cast and did not require surgery. At the time of the patient's last visit, a radiograph revealed a periosteal reaction as well as erosion of the bone cortex. Magnetic resonance imaging revealed an infiltrative area in the soft tissue surrounding the osteofibrous dysplasia lesion in the tibia. Consequent to pathological examination (through bone biopsy), the patient was diagnosed with secondary osteosarcoma. The patient underwent chemotherapy and extensive resection with liquid nitrogen. He has been progressing satisfactorily after the operation. The present case is the first report of secondary osteosarcoma associated with osteofibrous dysplasia. During the long-term follow-up of osteofibrous dysplasia, oncologists should be aware of the possibility of secondary osteosarcoma.

Dedifferentiation in low-grade osteosarcoma: a Japanese Musculoskeletal Oncology Group (JMOG) study.

BACKGROUND: Low-grade osteosarcomas, namely parosteal osteosarcoma (POS) and low-grade central osteosarcoma (LGCOS), occasionally dedifferentiate into high-grade malignancy, referred to as dedifferentiation in low-grade osteosarcoma (DLOS). This study aimed to elucidate the clinicopathologic features of DLOS, which are poorly described to date due to the extreme rarity of the disease. METHODS: A total of 33 patients with DLOS were included. Clinical characteristics, including the diagnostic accuracy of tumor biopsy, multimodal treatments, and clinical course, were retrospectively reviewed. Univariate analysis was performed to identify prognostic factors associated with overall survival (OS) and metastasis-free survival (MFS). RESULTS: The tumor subtypes comprised 10 cases (30.3%) of LGCOS and 23 cases (69.7%) of POS. The timing of dedifferentiation was synchronous in 25 (75.8%) and metachronous in 8 (24.2%) patients. The rates of preoperative diagnosis of DLOS were 40.0% and 65.4% for core needle biopsy and incisional biopsy, respectively. All patients underwent surgery and 25 patients received perioperative chemotherapy. Of the 13 patients who received neoadjuvant chemotherapy, 11 exhibited a poor histological response. The 5-year OS and MFS rates were 88.1% and 77.7%, respectively. Univariate analysis revealed that local recurrence was associated with poor OS (P < 0.01) and MFS (P < 0.01). Perioperative chemotherapy did not affect OS or MFS. CONCLUSIONS: The diagnostic accuracy of tumor biopsy for DLOS was lower than that for bone sarcomas, as reported previously. In contrast to conventional osteosarcomas with high chemosensitivity, both histological responses and survival analysis revealed low efficacy of chemotherapy for DLOS.

Myxoid liposarcoma originating in the retroperitoneum with metastasis to the calcaneus: a rare case report and review of literature.

Myxoid liposarcoma (MLPS) is known to have a variety of metastatic manifestations. We report a MLPS originating in the pelvis with metastasis to the calcaneus. The patient was a 72-year-old man who developed lumbar pain and right lower extremity pain 2 years ago. He visited a nearby clinic and underwent a radiographic examination. Computed tomography (CT) revealed a tumor in the right retroperitoneum. A CT-guided needle biopsy was performed, and pathological examination revealed myxoid liposarcoma. Wide surgical resection was not performed due to the patients' wishes, technical difficulties, and magnitude of the invasion, and the patient received heavy particle radiation therapy (HPRT) of 70.4 Gy. After HPRT, the tumor mass was slightly reduced. However, 11 months after HPRT, a recurrent lesion in the liver was observed. Although HPRT was performed again for the metastatic liver lesion (70.4 Gy), the tumor increased in size. Furthermore, 1 month later, the patient complained of pain in the left foot, and CT and magnetic resonance imaging revealed an osteolytic lesion in the calcaneus. A biopsy was performed, and pathological examination showed a metastatic lesion of myxoid-type liposarcoma. The patient wore a short lower limb orthosis and was able to walk but died 1 month later. Oncologists should note that MLPS can metastasize to the calcaneus.

Lung Adenocarcinoma Presenting as a Soft Tissue Metastasis to the Shoulder: A Case Report.

Background: Metastasis to soft tissue is rare, and the pathogenesis remains unclear. Soft tissue metastases (STMs) have varied presentations; existing reports are few. Herein, we report a case of STMs of the shoulder with a rich characterization. Case presentation: A 93-year-old man presented to our hospital with pain and swelling of the left shoulder for one week. Magnetic resonance imaging (MRI) showed a T1 low-intensity and T2 high-intensity mass. We suspected a primary sarcoma and performed a needle biopsy. However, on histopathological examination, the findings were suggestive of lung adenocarcinoma. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography also revealed FDG accumulation in the right lung, thus confirming the diagnosis. Conclusion: Oncologists should keep in mind that STMs of lung cancer may resemble soft-tissue sarcomas at the time of initial diagnosis.

Treatment Outcomes of Langerhans Cell Histiocytosis: A Retrospective Study.

Background and Objectives: Langerhans cell histiocytosis (LCH) is a rare disease characterized by the infiltration of one or more organs by Langerhans cell-like dendritic cells. LCH often involves the bone, and its clinical evidence is limited. The purpose of this study is to report on the treatment of LCH at our institution and to add to the evidence for LCH. Materials and Methods: We reviewed six cases of LCH treated in our hospital between November 2005 and February 2016. Patient age at the first visit, sex, site of origin, symptoms, image tools used for diagnosis, biopsy site, complications, treatment, and final clinical outcome were evaluated. The median follow-up period was 41 months. Results: The median patient age at the first visit was 13.5 years. Three male and three female individuals were enrolled. Multiple lesions were observed in five cases, and a solitary lesion was observed in one case. Pain was the chief complaint in five cases. Radiography was the most commonly used imaging tool. Bone scintigraphy or magnetic resonance imaging and positron emission tomography-computed tomography were also used to diagnose systematic LCH. Biopsy of the femur was performed in two cases, and biopsy of the tibia, lumbar vertebrae, rib, and radius was performed in one case each. Regarding comorbidities, one case of hepatitis B and one case of autism were observed. Chemotherapy was initiated in two patients. The other four patients were observed naturally. Continuous disease-free survival was observed in five patients. One patient remained alive but not without disease during the final follow-up examination. Conclusion: LCH should be diagnosed as early as possible to treat it appropriately.

Inflammatory Undifferentiated Pleomorphic Sarcoma Mimicking Bacteremia in an Elderly Patient: A Case Report.

Undifferentiated pleomorphic sarcoma (UPS) is major type of soft tissue sarcomas. UPS presenting with inflammation is rare, and its pathophysiology remains unclear. Herein, we report a rare case of UPS with prolonged fever. A 91-year-old female complaining of high fever was referred to our hospital because of a high C-reactive protein (CRP) level of 12.51 mg/dL. She had been experiencing intermittent fevers for approximately 10 years. The fever of unknown origin worsened with time and went into remission with repeated antimicrobial therapy. She also had a mass on her central lower back over the sacral region for 6 years, which showed a gradual increase in size. The blood tests showed that the leukocyte count and neutrophils were 6.51 × 103 /µL and 70.3%, respectively. She had a 10 × 10 cm mass on her buttock that showed 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) accumulation on FDG-positron emission tomography-computed tomography examination (standardized uptake value-max value: 5.4). A blood culture examination was performed to rule out bacteremia, however, no bacteria were identified. We then performed a needle biopsy and confirmed the diagnosis of UPS; subsequently, the patient underwent a wide-margin resection. A few days after the surgery, her CRP, leukocyte, and neutrophil levels decreased to 0.305 mg/dL, 2.83 × 103/uL, and 50.1%, respectively. This case demonstrated that UPS with inflammation should be treated surgically as soon as possible after ruling out other sources of infection to achieve a favorable prognosis.

Salmonella Osteomyelitis of the Rib Mimicking a Mammary Tumor: A Case Report.

Salmonella infection predominantly causes four clinical syndromes: enteric fever, gastroenteritis, bacteremia, and asymptomatic carrier state. Salmonella osteomyelitis is an extremely rare manifestation of salmonella infection except in children with hemoglobinopathies. Salmonella osteomyelitis has been reported to mostly affect the diaphysis of long bones and lumbar spine. Here, we describe a case of salmonella osteomyelitis of the right 6th rib in a 74-year-old woman who presented with breast pain, swelling, high fever and local heat. Her medical history showed myocardial infarction; namely, at the age of 71, the patient had undergone the drug-eluting stent placement in the left anterior descending artery. A computed tomography (CT) scan at the first visit to another hospital showed a mass in the chest that invaded the ribs. 18F-fluorodeoxyglucose-positron emission tomography-computed tomography imaging showed a lesion suspected to be a mammary malignant tumor. A needle biopsy revealed mesenchymal cells and suspected mammary sarcoma. However, the osteomyelitis of the rib was diagnosed when pyogenic tissue was observed during an open biopsy. The bacterial culture examination identified Salmonella enterica. Surgical drainage and antibiotic treatment were performed. Importantly, there was no evidence for any underlying disease that could lead to an immunocompromised status of the patient. To our knowledge, this is the first report of salmonella osteomyelitis of the rib presenting in an older female that required differentiation from a mammary tumor. Clinicians should consider rib osteomyelitis when they find swelling and local heat in the female's breast tissue and detect no cancerous tissue.

Soft Tissue Myoepithelioma of the Shoulder.

Soft tissue myoepitheliomas are often misdiagnosed due to their rarity. Herein, we describe a case of soft tissue myoepithelioma of the shoulder. A 72-year-old woman had a suspected sarcoma on her shoulder and under-went open biopsy. She was referred to our hospital, where the tumor was widely resected and the diagnosis of myoepithelioma was histologically confirmed. No recurrence has been observed in the 3 years since the sur-gery. Careful and prompt planning is necessary for the effective treatment of myoepithelioma.

Salmonella Osteomyelitis of the Distal Tibia in a Healthy Woman.

Salmonella osteomyelitis is extremely rare; only a few cases have been reported in healthy adults. We describe a case of salmonella osteomyelitis in an otherwise healthy 20-year-old Japanese woman who presented with distal tibial pain. X-ray and magnetic resonance imaging showed a lesion suspected to be a bone cyst. Osteomyelitis was diagnosed when pus was observed during an open biopsy. The bacterial culture examination yielded salmonella. Surgical drainage and antibiotic treatment were performed, after which no recurrence was observed. To our best knowledge, this is the first report of salmonella osteomyelitis of the distal tibia in an otherwise healthy individual.

Grisel's Syndrome After COVID-19 in a Pediatric Patient: A Case Report.

An eight-year-old female presenting with posterior neck pain and torticollis who had been diagnosed with coronavirus disease 2019 (COVID-19) three weeks earlier was radiographed and diagnosed with atlantoaxial rotatory fixation (AARF). Following treatment with non-steroidal anti-inflammatory drugs (NSAIDs), the posterior neck pain improved, and the torticollis was cured. Symptoms returned after two weeks, and computed tomography showed a 3.94 mm atlantodental interval and axis rotation. The patient was diagnosed with AARF relapse; symptoms resolved spontaneously prior to subsequent examination, and no further relapses were observed. This case highlights the need for clinicians to be aware that AARF may develop after COVID-19. Treatment options should be carefully considered.

Total management of hemangiopericytoma/solitary fibrous tumor of the buttock: A case report.

BACKGROUND: Solitary fibrous tumors can manifest at various anatomical sites, predominantly occurring at extrapleural sites with a peak incidence between 40 and 70 years. SFT necessitates long-term follow-up owing to its tumor characteristics. However, comprehensive reports covering the period from initial diagnosis to the patient's demise are lacking. Herein, we present a case of a malignant SFT of the buttocks that was treated at our hospital from the time of initial diagnosis to the end of life, with a literature review. METHODS: A 54-year-old woman had a T1 low-to-isobaric and T2 isobaric-to-hyperintense mass in the psoas muscle on magnetic resonance imaging, diagnosed as an SFT. Wide excision was performed, followed by postoperative radiotherapy and chemotherapy. Multiple lung metastases were treated, while bone metastases appeared in the left femur. Multiple spinal metastases developed, causing respiratory distress due to pleural effusion. Best support care was initiated; however, a thrombus appeared in the inferior vena cava. Despite anticoagulant therapy, the patient died 11 years and 6 months after the initial surgery. Herein, marginal resection resulted in a relatively short operative time and average blood loss. The radiotherapy dose was 66 Gy; no complications occurred, and local recurrence was prevented. Tumor arthroplasty was performed to stabilize the affected limbs, and the patient required careful follow-up. RESULTS: Despite the poor prognosis, the patient survived >11 years after surgery and had a favorable outcome. CONCLUSION: Long-term monitoring for potential complications remains necessary.

Treatment algorithm for metastatic malignancies in the lower extremities.

A high prevalence of proximal femoral metastases persists in patients with cancer, particularly regarding lower extremity fractures. This study offers a detailed analysis of clinical characteristics of patients undergoing surgical treatment for pathological or impending fractures, enhancing treatment strategies for metastatic malignancies. A total of thirty patients who underwent treatment of impending and pathological fractures at Kindai University Hospital (Osakasayama, Japan) were included. The retrospective study comprised parameters including age, sex, fracture site, type of primary malignancy, number of metastases, pre-fracture Eastern Cooperative Oncology Group performance status (ECOG-PS) score, adjuvant therapy, treatment modality, operative time, blood loss, postoperative complications, Musculoskeletal Tumor Society (MSTS) score, outcome and follow-up period. Post-treatment MSTS scores were compared in cases of impending and pathological fractures, and between intramedullary nailing and other surgical procedures. In addition, one-year postoperative survival rates were calculated. Furthermore, operative time, blood loss and survival rates were compared between impending and pathological fractures. The participants' median age was 70.5 years, with disease sites primarily in the subtrochanteric femur, trochanteric femur, femoral diaphysis, femoral neck and other locations. Pathologies included multiple myeloma and unknown primary, lung, breast, kidney, liver, gastric, esophageal and uterine cancers. The median ECOG-PS score pre-fracture was 2. Treatment approaches involved radiotherapy, chemotherapy and a combination of both. Surgical interventions included intramedullary nailing (16 cases), endoprosthesis (1 case), bipolar head replacement (3 cases) and compression hip screw (3 cases), among others. A negative correlation (R=-0.63) existed between MSTS and pre-fracture ECOG-PS scores. The operative time was significantly shorter in impending than in pathological fractures, with impending fractures showing significantly lower blood loss. The treatment algorithm for malignant bone tumors of the lower extremity provided in the present study was efficient, potentially optimizing treatment strategies for such cases, and contributing to improved patient care and outcomes in oncology and orthopedic surgery.

Oncological and functional outcomes of pathological fractures of lower extremities in patients with malignant bone tumors.

As managing pathological fractures of the extremities can be difficult, the present study aimed to present a treatment algorithm for lower extremity bone malignancies. A total of 38 patients with impending and pathological fractures were treated at the Department of Orthopedic Surgery in Kindai University Hospital. Age, sex, fracture site, type of primary malignancy, number of metastases, pre-fracture Eastern Cooperative Oncology Group performance status (ECOG-PS) score, adjuvant therapy, treatment modality, operative time, blood loss, postoperative complications, Musculoskeletal Tumor Society (MSTS) score, outcomes, follow-up period and the MSTS scores and ECOG-PS were compared in cases of primary malignant tumors and those cases of metastatic malignant tumors were retrospectively surveyed. Post-treatment MSTS scores in cases of impending and pathological fractures were compared between intramedullary nail fixation and non-intramedullary nail fixation procedures. Disease sites included the sub-trochanteric femur in 10 patients, trochanteric femur in 8, femoral diaphysis in 7, femoral neck in 5, bilateral trochanteric femur in 3, proximal tibia in 3 and distal femur in 2 patients. A total of 10 patients had metastases between 3-20 sites. The median pre-fracture ECOG-PS score was 1. Adjuvant radiotherapy was administered to 5, chemotherapy to 8 and radiotherapy with chemotherapy to 10 patients. Surgical procedures included intramedullary nails in 18 patients, tumor arthroplasty in 4, plate fixation in 3, artificial head replacement in three, compression hip screw (CHS) in 3, conservative treatment in 2, bilateral intramedullary nail fixation in 2 and artificial bone stem with combined intramedullary nail and plate fixation, right-sided artificial head replacement and left-sided CHS in 1 patient each. The MSTS score was 19.9±8.95 for intramedullary nail fixation and 24.3±7.45 for other procedures, with a negative association between the MSTS score and pre-fracture ECOG-PS. The median follow-up period was 8 months. The outcomes were as follows: Alive with disease, 23 patients; continued disease-free, 1 patient; and dead due to disease, 14 patients. The 1-year postoperative overall survival rate was 60.5%. Moreover, the group with metastatic malignant tumors, which had significantly worse ECOG-PS, had significantly lower MSTS scores than the group with primary malignant tumors. The authors' treatment algorithm for malignant bone tumors of the lower extremity was shown to be useful.

Involvement of NY-ESO-1 and MAGE-A4 in the pathogenesis of desmoid tumors.

The involvement of New York esophageal squamous cell carcinoma-1 (NY-ESO-1) and melanoma-associated antigen A4 (MAGE-A4) in soft-tissue sarcoma pathogenesis has recently been reported; however, their involvement in desmoid tumors (DTs) remains unknown. This study aimed to determine the involvement of NY-ESO-1 and MAGE-A4 in DTs. Immunostaining for ß-catenin, NY-ESO-1, and MAGE-A4 was performed on DT biopsy specimens harvested at our institution. The positivity rate for each immune component was calculated. In addition, the correlations between the positivity rates for the immune molecules were investigated. The correlation between the positivity rate and age or longest diameter of each immune molecule was also investigated. ß-catenin showed staining mainly in the tumor cell nuclei of DTs. Both NY-ESO-1 and MAGE-A4 showed staining in the nucleus, cytoplasm, and infiltrating lymphocytes of DT cells. The mean positive cell rates for ß-catenin, NY-ESO-1, and MAGE-A4 were 43.9 ±â€…21.7, 30 ±â€…21.6, and 68.9 ±â€…20.8, respectively. A strong negative correlation was observed between ß-catenin and MAGE-A4 positivity rates (r = -0.64). The positivity rates for NY-ESO-1 and MAGE-A4 showed a moderate positive correlation (r = -0.42). A very strong negative correlation was observed between age and the NY-ESO-1 positivity rate (r = -0.72). A weak negative correlation was observed between age and the MAGE-A4 positivity rate (r = -0.28). A medium negative correlation was observed between the longest tumor diameter and NY-ESO-1 positivity (r = -0.37). NY-ESO-1 and MAGE-A4 may be involved in the DT microenvironment. Thus, NY-ESO-1 and MAGE-A4 may be useful in the diagnosis of DT.

Clinicopathological assessment of PD-1/PD-L1 immune checkpoint expression in desmoid tumors.

The details of immune molecules' expression in desmoid tumors (DTs) remain unclear. This study aimed to determine the expression status of the programmed death-1/programmed death ligand 1 (PD1/PD-L1) immune checkpoint mechanism in DTs. The study included patients with DTs (n=9) treated at our institution between April 2006 and December 2012. Immunostaining for CD4, CD8, PD-1, PD-L1, interleukin-2 (IL-2), and interferon-gamma (IFN-γ) was performed on pathological specimens harvested during the biopsy. The positivity rate of each immune component was calculated as the number of positive cells/total cells. The positivity rate was quantified and correlations between the positivity rates of each immune molecule were also investigated. Immune molecules other than PD-1 were stained in tumor cells and intra-tumor infiltrating lymphocytes. The mean ± SD expression rates of ß-catenin, CD4, CD8, PD-1, PD-L1, IL-2, and IFN-ɤ were 43.9±18.9, 14.6±6.80, 0.75±4.70, 0±0, 5.1±6.73, 8.75±6.38, and 7.03±12.1, respectively. The correlation between ß-catenin and CD4 was positively moderate (r=0.49); ß-catenin and PD-L1, positively weak (r=0.25); CD4 and PD-L1, positively medium (r=0.36); CD8 and IL-2, positively medium (r=0.38); CD8 and IFN-ɤ, positively weak (r=0.28); and IL-2 and IFN-ɤ, positively medium (r=0.36). Our findings suggest that PD-L1-centered immune checkpoint mechanisms may be involved in the tumor microenvironment of DTs.

Aggressive intraosseous lipoma of the scapula: A case report.

The details of the pathogenesis of intraosseous lipomas are not fully elucidated, although most cases do not require surgical treatment. The present report describes the case of a 79-year-old female patient diagnosed with intracapsular lipoma who also exhibited an extraosseous extension. Chest computed tomography revealed an abnormal shadow or a mass in the right scapula and destruction of the glenoid bone. Magnetic resonance imaging revealed a high-intensity mass on T1-weighted and T2-weighted images in the same area. Marginal resection of the mass was performed. The histopathology confirmed that the mass was a lipoma. No postoperative recurrence was observed. Oncologists must be aware that lipoma arising within the scapula may extend outside the bone.

Malignant giant cell tumor of toe: A case report and review of literature.

INTRODUCTION: A giant cell tumor of soft tissue (GCST) is a benign soft tissue tumor that often occurs subcutaneously in the extremities. Rare cases of malignant GCST have been reported, but its pathogenesis remains unclear. PATIENTS CONCERNS: We report a case of a 68-year-old man who noticed a painless mass on his second toe one and a half years ago. He visited the Department of Dermatology at our hospital. Magnetic resonance imaging revealed a soft tissue tumor, surrounding the distal aspect of the second toe. DIAGNOSIS: A biopsy of the tumor was performed by a dermatologist, and it revealed a malignant giant cell tumor of the toe. INTERVENTIONS: He was referred to our department and underwent lay amputation for wide-margin resection. OUTCOMES: No recurrence or metastasis was observed 5 years after treatment. CONCLUSION: : Malignant GCST should be treated with wide-margin resection immediately after its diagnosis.

Clinicopathological Assessment of Cancer/Testis Antigens NY-ESO-1 and MAGE-A4 in Highly Aggressive Soft Tissue Sarcomas.

We aimed to investigate the clinical significance of the expression of NY-ESO-1 and MAGE-A4 in soft tissue sarcoma (STS). Immunostaining for NY-ESO-1, MAGE-A4, and Ki67 was performed using pathological specimens harvested from 10 undifferentiated pleomorphic sarcoma (UPS), nine myxofibrosarcoma (MFS), and three malignant peripheral nerve sheath tumor (MPNST) patients treated at our hospital. We examined the correlation of NY-ESO-1 and MAGE-A4 expression levels with tumor size, histological grade, and SUVmax values. Positive cell rates of various markers were also compared between patients in remission and those who were not in remission. The rates of cases positive for NY-ESO, MAGE-A4, and Ki67 were 50%, 63.6%, and 90.9%, respectively. The average rates of cells positive for NY-ESO, MAGE-A4, and Ki67 in all STS types were 18.2%, 39.4%, and 16.8%, respectively. A positive correlation was observed between rates of cells positive for NY-ESO-1 and MAGE-A4 and between NY-ESO-1 and MAGE-A4 expression levels and clinical features. There was no significant difference in the positive cell rate of NY-ESO-1 or MAGE-A4 between remission and non-remission cases. Our results suggest that NY-ESO-1 and MAGE-A4 expression may be useful for the diagnosis and prognostication of UPS, MFS, and MPNST.