Ukei Anazawa

Metastatic Patterns of Myxoid/Round Cell Liposarcoma: A Review of a 25-Year Experience

Myxoid/round cell liposarcoma (MRCL), unlike other soft tissue sarcomas, has been associated with unusual pattern of metastasis to extrapulmonary sites. In an attempt to elucidate the clinical features of MRCL with metastatic lesions, 58 cases, from the medical database of Keio University Hospital were used for the evaluation. 47 patients (81%) had no metastases, whereas 11 patients (11%) had metastases during their clinical course. Among the 11 patients with metastatic lesions, 8 patients (73%) had extrapulmonary metastases and 3 patients (27%) had pulmonary metastases. Patients were further divided into three groups; without metastasis, with extrapulmonary metastasis, and with pulmonary metastasis. When the metastatic patterns were stratified according to tumor size, there was statistical significance between the three groups (P = 0.028). The 8 cases with extrapulmonary metastases were all larger than 10 cm. Similarly, histological grading had a significant impact on metastatic patterns (P = 0.027). 3 cases with pulmonary metastatic lesions were all diagnosed as high grade. In conclusion, large size and low histological grade were significantly associated with extrapulmonary metastasis.

Detection of HEY1‐NCOA2 fusion by fluorescence in‐situ hybridization in formalin‐fixed paraffin‐embedded tissues as a possible diagnostic tool for mesenchymal chondrosarcoma

Mesenchymal chondrosarcoma (MC) is an extremely rare subtype of chondrosarcoma. A tumor specific fusion gene, HEY1‐NCOA2 fusion, was recently identified in this tumor. The finding raises the possibility that the diagnosis of MC can be improved by examining the fusion gene. In the present study, we aimed to evaluate the efficacy of fluorescence in situ hybridization (FISH) in detecting HEY1‐NCOA2 fusion for the diagnosis of MC. Specimens from 10 patients diagnosed with MC were used for the study. Dual‐color FISH was performed using two different probes that specifically hybridize to HEY1 and NCOA2, respectively. Fusion signals were identified in all but two specimens, in which no signal was detected, presumably because of inadequate sample preparation. In accordance with results of a previous study, FISH analysis was highly sensitive in detecting HEY1‐NCOA2 fusion in adequately prepared MC samples. The current study adds further support for the use of HEY1‐NCOA2 fusion as a valid diagnostic marker for MC.

Postoperative deep infection in tumor endoprosthesis reconstruction around the knee

BackgroundAlthough deep infection remains one of the most difficult complications to manage in the treatment of musculoskeletal tumor reconstructed with an endoprosthesis, limited information with respect to its incidence and risk factors has been reported.MethodsThis multicenter, retrospective, uncontrolled study reviewed the medical records of 82 patients who underwent reconstruction with an endoprosthesis or temporary spacer for bone-immature patients after resection of malignant bone tumor around the knee. Risk factors for deep infection and the impact of deep infection on prosthesis survival and oncological outcomes were analyzed. Deep infection was defined according to the Centers for Disease Control and Prevention (CDC) guidelines with minor modification.ResultsDeep infection occurred in 14 cases (17%), identified at a mean of 10.9 months (range <1 to 48 months) after initial surgery. Univariate analysis identified surface infection (P < 0.001) and skin necrosis (P < 0.001) as risk factors associated with deep infection. Conversely, tumor origin, chemotherapy, number of postoperative antibiotics, and length of bone resection were not associated with infection. Subclass analysis in femur cases identified a correlation between infection and the extent of partial resection of the quadriceps muscle (P = 0.04). In the multivariate analysis, surface infection represented an independent risk factor for deep infection (P = 0.03). Deep infection was a risk for endoprosthesis survival (P = 0.003) but did not affect the oncological outcome.ConclusionsA strong correlation between the condition of soft tissue and establishment of deep infection is suggested in this study. Although practical options for preventing deep infection seem limited, the present data allow a form of perioperative evaluation for patients with a higher risk of deep infection.

Similarities between giant cell tumor of bone, giant cell tumor of tendon sheath, and pigmented villonodular synovitis concerning ultrastructural cytochemical features of multinucleated giant cells and mononuclear stromal cells.

The authors investigated ultrastructural cytochemical features of multinucleated and mononuclear stromal cells in giant cell tumor of bone (GCTB), giant cell tumor of tendon sheath (GCTTS), and pigmented villonodular synovitis (PVNS). Specimens of each tumor, respectively numbering 4, 4, and 3, were stained for tartrate-resistant acid phosphatase (TRAP) reactions and examined with an electron microscope. In GCTB and GCTTS, multinucleated cells, including some relatively small giant cells, showed TRAP activity and cytoplasmic features characteristic of osteoclasts, and also sometimes abundant rough endoplasmic reticulum and siderosomes. A few giant cells with macrophage-like features and slight TRAP activity were demonstrated in GCCTS and PVNS. In each tumor type, mononuclear cells showing TRAP activity shared cytoplasmic features with osteoclast-like multinucleated giant cells, while some others had macrophage-like features, and still others were poorly differentiated; a few mononuclear cells showed cell-to-cell contact. Ultrastructural similarities of TRAP-positive mononuclear cells in the three tumor types, and those between TRAP-positive multinucleated cells in GCTB and GCTTS, suggest a common cell lineage capable of multinucleated giant cell formation in the 3 tumors, despite differing histogenesis.

Clinical significance of magnetic resonance imaging in the preoperative differential diagnosis of calcifying aponeurotic fibroma

BackgroundAlthough the clinical and histological features of calcifying aponeurotic fibroma are well described, the magnetic resonance imaging (MRI) findings have been reported for only five cases. The purpose of this study was to describe a series of MRI findings in this rare entity to assess its utility in preoperative and differential diagnosis.MethodsMRI findings together with the clinical signs and radiographs of six patients with pathologically proven calcifying aponeurotic fibroma were retrospectively reviewed. Distribution, morphology, margins, edematous changes, and relation to the surrounding structures together with signal intensity of each sequence of MRI were evaluated.ResultsMRI demonstrated subcutaneous distribution, ill-defined appearance, and a tendency to infiltrate into or adhere to the surrounding tissues. The masses were of isointensity to low intensity on T1-weighted images. T2-weighted images showed heterogeneous high signal intensity with minor areas of isointensity to low signal intensity. Postcontrast T1-weighted images demonstrated heterogeneous intense enhancement.ConclusionsMRI revealed several features that can contribute to the preoperative differential diagnosis of calcifying aponeurotic fibroma from other fibrous tumors, giant cell tumor of the tendon sheath, or soft tissue sarcoma. As a result, MRI would help orthopedic oncologists plan the surgery for this rare entity.

Natural evolution of desmoplastic fibroblastoma on magnetic resonance imaging: a case report

IntroductionDesmoplastic fibroblastoma (collagenous fibroma) is a recently described tumor thought to arise predominantly from subcutaneous tissue or skeletal muscle. The natural evolution of this tumor on magnetic resonance imaging has never been described, to the best of our knowledge. We herein report a case of desmoplastic fibroblastoma arising in the thigh and show the longitudinal magnetic resonance imaging findings.Case presentationA 60-year-old Japanese man presented with swelling of the medial side of his right thigh, and he complained of nighttime pain and slight tenderness. Magnetic resonance imaging demonstrated a 4 × 4 cm mass in the right thigh. Open biopsy was performed. The mass was diagnosed histologically as a benign fibrous tumor, and we maintained follow-up without surgical therapy. After one year, magnetic resonance imaging showed an increase in tumor size to 4 × 5 cm, but the histologic findings were the same as those obtained one year earlier. Resection was performed with narrow surgical margins. Pathologic diagnosis was desmoplastic fibroblastoma. Two years after surgery, the patient is free from pain and shows no signs or symptoms of recurrence.ConclusionThe natural evolution of desmoplastic fibroblastoma is characterized by no changes in patterns on magnetic resonance imaging despite increasing size. This finding is clinically helpful for distinguishing desmoplastic fibroblastoma with increasing pain from the desmoid tumor.

Primary bone carcinosarcoma: Chondrosarcoma and squamous cell carcinoma with keratin pearl formation

Malignant bone tumors with epithelial differentiation are extremely rare. Only one case of primary malignant bone tumor with distinct squamous cell carcinoma and chondrosarcoma has ever been reported. Reported herein is a case of primary malignant bone tumor with distinct squamous cell carcinoma and chondrosarcoma, so‐called carcinosarcoma of bone, arising in the femur of a 53‐year‐old man. The tumor was located within the femur and was diagnosed by curettage as a well‐differentiated chondrosarcoma. No primary tumor was detected in any other organ. Within a few months the tumor had rapidly grown toward the soft tissue, and hemipelvectomy was performed. Examination of the surgical specimen revealed that the tumor was mainly composed of undifferentiated spindle sarcoma cells with scattered foci of chondrosarcoma and of squamous cell carcinoma with keratin pearl formation. The patient died approximately 6 months postoperatively. At autopsy multiple metastases were detected in the heart, both lungs, muscles, and lymph nodes. Interestingly, the chondrosarcoma and squamous cell carcinoma components were observed in several metastatic foci. The tumors in both the previously reported case and the present case contained components of chondrosarcoma and squamous cell carcinoma with keratin pearl formation, and this combination of histological features may be a unique characteristic of carcinosarcoma of bone.

Ultrastructural Cytochemical and Ultrastructural Morphological Differences Between Human Multinucleated Giant Cells Elicited by Wear Particles from Hip Prostheses and Artificial Ligaments at the Knee

The authors investigated the ultrastructural cytochemical features of multinucleated and mononuclear cells in periprosthetic tissues associated with bone resorption (osteolysis) and those in tissues adjoining failed artificial ligaments having no relation to bone resorption. Clinical specimens of granulation tissue of each type, respectively numbering 4 and 3, were stained for tartrate-resistant acid phosphatase (TRAP) reactions and examined by light and electron microscopy. Both periprosthetic granulation tissues and those adjoining artificial ligaments contained TRAP-positive multinucleated and mononuclear cells. Near joint prostheses, multinucleated cells, including some giant cells, showed TRAP activity and cytoplasmic features resembling osteoclasts, while others had features consistent with foreign-body giant cells, and still others showed degenerative changes. Near artificial ligaments, TRAP-positive multinucleated cells lacked osteoclastic features. At both sites, TRAP-positive multinucleated cells had phagocytised wear particles. TRAP-positive mononuclear cells at both sites also showed phagocytic cytoplasmic features, but not osteoclastic cytoplasmic features. Human mononuclear phagocytes and multinucleated giant cells induced by wear particles possess TRAP activity. Those multinucleated giant cells at sites of osteolysis developed osteoclastic cytoplasmic features and have a phagocytic function.

A case of metacarpal chondrosarcoma of the thumb

Enchondroma is the most common primary benign bone tumor of the hand. Chondrosarcomas in this location, however, are extremely rare. It often is difficult to make a histological distinction between benign cartilaginous tumors and low-grade chondrosarcomas, because enchondromas at this site often show histological features suggestive of malignancy. However, distinguishing the two conditions is clinically relevant because chondrosarcomas of the hand require prompt and more radical treatments such as ray amputations. On the other hand, Mankin has recently given attention to a less aggressive behavior of chondrosarcomas of the phalanges compared with those of other locations. And also, ray amputation does not cause much functional deficit in the finger but does for the thumb. This is a case report of chondrosarcoma affecting the metacarcal bone of the thumb, treated by en block resection and preserving the function of the thumb by bone graft reconstruction, with reference to the literature.

Arthroscopic removal of intra-articular osteoid osteoma in the knee : case report and review of the literature

Abstract Osteoid osteoma is a relatively common benign bone tumor first described by Jaffe [1]. It most frequently arises in the long bones and exhibits a characteristic X-ray appearance, that is, a small radiolucent zone surrounded by reactive circumferential sclerosis (nidus) [2, 3]. Nocturnal pain, which can be alleviated by aspirin, is one of the characteristic clinical manifestations of this bone tumor [4]. Although it is relatively rare, osteoid osteoma can also arise in the intra-articular regions, and we found 14 such cases arising in the knee joint in the literature [5–18]. Patients with intra-articular osteoid osteoma often present with joint pain, intracapsular effusion, restricted motion, and muscle atrophy in the affected limb, which can be mistaken for more common entities, such as traumatic or degenerative pathologies of the joint. Furthermore, X-ray examination often fails to show the characteristic nidus that is typically seen in extra-articular osteoid osteoma and therefore can result in a delayed diagnosis. We herein present a case of intra-articular osteoid osteoma arising in the knee joint, which was successfully treated by arthroscopy, and review the reported cases of intra-articular osteoid osteoma arising in the knee.