Undiagnosed synovial hemangioma of the knee: a case report.

BACKGROUND: Synovial hemangioma of the knee is a rare benign tumor. Very rarely, the growth of bone is affected by long-term neglect of an intra-articular tumor. Our patient had not only various clinical symptoms but also dysplasia of the femoral bone. In this report, we aimed to raise awareness to prevent various disorders arising from an unnoticed or untreated hemangioma occurring within the knee joint. CASE PRESENTATION: Our patient was a 41-year-old Japanese man who had had occasional discomfort in the right knee since elementary school. Although he had undergone radiography at several hospitals since childhood, no issues were reported; subsequently, he consulted our hospital. We performed magnetic resonance imaging and discovered a mass. The mass was homogeneous with low intensity on T1-weighted sequences and high intensity on T2-weighted sequences adjacent to the medial femoral condyle. The shape of the medial femoral condyle presented with a concavity in axial images, with irregular margins from the patellofemoral joint to the medial femoral condyle. Moreover, by using magnetic resonance angiography, we discovered a second mass. We decided to perform open surgery to achieve complete excision. Histological examination indicated a synovial hemangioma involving a cavernous hemangioma and irregular arteriovenous connections originating from the subsynovial tissue. The patient became asymptomatic after surgery, with no recurrence for more than 4 years. CONCLUSIONS: Synovial hemangioma is rare and difficult to diagnose in outpatient examinations because radiography has a limited diagnostic capacity. Magnetic resonance imaging and angiography are very useful. Nontreatment of intra-articular hemangiomas may lead to dysplasia of the bone and various clinical symptoms. Early complete excision may be instituted to reduce these risks of hemarthrosis.

Bizarre soft tissue tumour on the gluteus muscle: a case report of spontaneous chronic expanding haematoma.

Chronic expanding haematoma (CEH) is rare and refers to a gradually increasing haematoma that is not absorbed after surgery and trauma. This report highlights unusual mass occurring on the gluteus muscle, and the aim is to indicate the diagnostic method. It is necessary to consider the mechanism of the occurrence and to know the characters of CEH. The patient was a 51-year-old man who had noticed a soft mass on his right hip. The mass had gradually increased to 10 cm in size over the year. CT images revealed a haematoma. However, MRI showed a rare biphasic fluid-fluid layer inside the mass and indicated a different pattern compared with that of a normal haematoma. Because the mass was affecting the patient's social life, and the diagnosis was difficult to confirm, surgical treatment was elected. Intraoperatively, the mass contained a large amount of a brown mud-like substance and showed the bizarre appearance inside. The mass was diagnosed as CEH based on both the clinical findings and the histopathological diagnosis. The patient had no traumatic event and no previous surgery. In the absence of the clinical history and the unique imaging findings, it was difficult to diagnose the mass as CEH. It is important to clarify a patient's underlying disease, history, and lifestyle and to consider any correlation between the mass location and the patient's condition carefully. Considering the character of the mass and the lack of a preoperative definitive diagnosis, we recommend performing complete surgical resection.

Type 1 neurofibromatosis with a giant intrathoracic lesion: a case report with 25 years of follow-up.

We report a case of neurofibromatosis 1 with a huge intrathoracic lesion followed-up for 25 years. When the patient was 5 years of age, we performed a partial resection as an excisional biopsy. Microscopically, small spindle cells and collagen were spread between fat cells. A CT scan revealed a large intrathoracic mass, but tumor growth increasingly retarded as the patient grew older. During the entire 25-year follow-up period, from 5 to 30 years of age, the patient showed no neurological signs or other clinical symptoms. The findings of our case suggest that for a neurofibromatosis 1 patient, a good prognosis can be expected even if a huge destructive intrathoracic intrusion is detected. To assess the risk of malignant transformation, follow-up is required, accompanied by appropriate diagnostic modalities and physical examinations.

Epiphyseal preservation and an intercalary vascularized fibular graft with hydroxyapatite composites. Reconstruction in metaphyseal osteosarcoma of the proximal tibia: a case report.

UNLABELLED: BACKGROUND DATA AND OBJECTIVES: We present here a case report of a patient with metaphyseal osteosarcoma with a preserved epiphysis and reconstructed by a vascularized fibular graft and hydroxyapatite composites. METHODS: The case was a 14-year-old boy, who had osteosarcoma in the proximal tibia. After the diagnosis was confirmed by biopsy, the patient immediately received preoperative chemotherapy including high-dose Methotrexate, Cisplatin and Doxrubicin. Imagings after preoperative chemotherapy including MRI and contrasted enhanced CT confirmed no tumor penetration into the physis. Subsequently, we performed transepiphyseal resection of the proximal tibia to reserve the joint surface. The intercalary twin-barreled vascularized fibular graft was placed with hydroxyapatite composites. The patella tendon was reattached to the grafted fibular to biologically reconstruct the knee extensor mechanism. Postoperative chemotherapy was completed with the same regime as preoperative chemotherapy. OUTCOMES: The bony union was completed at 10 months after the operation. The Enneking's functional evaluation score was 28 out of 30 points (93%). There was no evidence of local recurrence and no metastatic disease during the 42 months follow-up after initial diagnosis. CONCLUSION: An accurate evaluation of MRI and CT can give a reliable assessment of intraphyseal penetration of metaphyseal osteosarcoma. In case of no involvement of the tumor in the physis, transepiphyseal osteotomy is the optimal procedure to preserve the joint surface and superior function of the joint, especially in the proximal tibia.

Adamantinoma-like Ewing's sarcoma with EWS-FLI1 fusion gene: a case report.

Recent studies have advocated the genotypic and phenotypic delineation of a novel Ewing's sarcoma histologic variant showing epithelial features defined as "adamantinoma-like Ewing's sarcoma". We described an 18-year-old girl with a primary small round-cell sarcoma of the right tibia showing polyphenotypic differentiation with epithelioid features. The neoplastic cells had mainly round or oval nuclei with fine chromatin with a portion of epithelial arrangements. The immunohistochemical analysis showed the epithelial markers of cytokeratin 5/6/18, AE1/AE3, and cytokeratin high molecular weight were stained especially in the foci with epithelioid features, as well as MIC2, S100, and NSE. The diagnosis of the lesion was confirmed as Ewing's sarcoma by the presence of the EWS-FLI1 fusion transcript, and could be defined as the so-called "adamantinoma-like Ewing's sarcoma". After wide excision and high-dose chemotherapy with peripheral blood stem cell transfusion, the patient has been well and continuously event-free for 3 years since the initial diagnosis.

Growth inhibition and induction of apoptosis by flavopiridol in rat lung adenocarcinoma, osteosarcoma and malignant fibrous histiocytoma cell lines.

Flavopiridol is the potent inhibitor of cdks sharing its function with endogenous cdk inhibitors, and causes arrest at both the G1 and G2 phases of the cell cycle resulting in apoptosis in various tumor cell lines. Cyclin-dependent kinase inhibitor p16INK4a induces cell cycle arrest in G1 or G2 or both, and is inactivated in many malignant tumors. In this study, we focused on the effects of flavopiridol on chemically-induced rat lung adenocarcinoma, osteosarcoma and malignant fibrous histiocytoma (MFH) cell lines showing different pattern of p16INK4a status. The data demonstrated that flavopiridol inhibited cellular growth in a dose- and time-dependent manner, inducing apoptosis within 24 h in all cell lines at a concentration of 300 nM. The growth inhibition rate was the greatest for lung adenocarcinoma cells, lacking p16INK4a expression associated with methylation-mediated gene silencing; 83% at a concentration of 300 nM for 72-h treatment; while the growth of osteosarcoma and MFH cells, both expressing p16INK4a, were inhibited at similar levels; 54-61% for osteosarcoma and 61-64% for MFH cell lines. Then, we further investigated the influence of p16INK4a induction upon the effect of flavopiridol in p16INK4a-deficient lung adenocarcinoma cells. 5-aza 2'-deoxycytidine (5-Aza-CdR) induced p16INK4a expression and inhibited cellular growth in lung adenocarcinoma at a similar level to that with flavopiridol treatment. After the induction of p16INK4a expression by 5-Aza-CdR, the growth inhibition rates of flavopiridol in the p16INK4a-induced lung adenocarcinoma cells could not achieve comparable inhibition to that in the p16INK4a-deficient cells; the efficacy was reduced compared to original p16INK4a-deficient cells at each concentration of 50, 100 and 500 nM for 72-h treatment. These data indicate that flavopiridol shows cell type specific inhibition and possibly acts in a more compensatory manner for endogenous p16INK4a function in tumor cells having the aberrations of p16INK4a gene.

Expression of the p16INK4a gene and methylation pattern of CpG sites in the promoter region in rat tumor cell lines.

Loss of p16(INK4a) protein expression has frequently been related to DNA methylation in association with gene silencing. Although the methylation status of exon1alpha for p16(INK4a) involvement in various cancers has been extensively analyzed, it has been pointed out that some inconsistencies existed in its relationship to gene silencing of p16(INK4a). In this study, we focused on the expression and methylation status in the regions of nt -478 to -201, containing a putative TATA box (nt -401 to -396), and nt -233 to 26, both in a recently cloned 5' upstream region of rat p16(INK4a). We showed that rat lung adenocarcinoma RLCNR did not express the p16(INK4a) gene, whereas rat osteosarcoma COS1NR and malignant fibrous histiocytoma MFH1NR both expressed it at levels similar to normal fibroblasts, even though the region of nt -233 to 26 was hypermethylated in COS1NR rather than RLCNR. In contrast, the CpG islands near the putative TATA box region were consistently methylated in RLCNR, but not in COS1NR and MFH1NR, as well as in normal fibroblasts. Treatment with 5-aza 2'-deoxycytidine induced expression of p16(INK4a) gene in RLCNR after 48 h, but no changes were observed in COS1NR and MFH1NR. The results indicated that methylation of CpG islands near a TATA box region played a critical role for gene silencing of the rat p16(INK4a) gene, rather than that of other regions.

Growth inhibition of rat osteosarcoma and malignant fibrous histiocytoma cells by tyrosine kinase inhibitor STI571.

STI571 is a 2-phenylaminopyrimide derivative that was designed as an Abl tyrosine kinase inhibitor, but it is also effective against platelet-derived growth factor receptor (PDGFR) and c-Kit tyrosine kinase. Recent studies have demonstrated that STI571 inhibits the growth of several tumors in which PDGF or c-kit play an important role in tumor pathogenesis. We have recently established rat osteosarcoma and malignant fibrous histiocytoma (MFH) cell lines. RT-PCR analysis revealed that MFH and osteosarcoma cell lines expressed high and very low levels of PDGFR alpha respectively, and that all cell lines expressed similar levels of PDGFR beta. The level of c-kit mRNA expression were almost negligible hardly in all cell lines. The effect of STI571 on cellular growth measured by MTS colorimetric dye reduction showed that the growth of each cell line was inhibited in a dose- and time-dependent manner. STI571 (10 microM) inhibited the rates of cell growth of MFH cells by up to 40% and of osteosaroma cells by only to 20% after 72 hours. These data suggested that STI571 tyrosine kinase inhibitor plays a role in blocking or slowing the rate of growth of MFH and osteosarcoma cells expressing tyrosine kinase type receptor.

Differential expression of cytokines in rat osteosarcoma and malignant fibrous histiocytoma cell lines induced by 4-(hydroxyamino)quinoline-1-oxide.

Cytokines are considered to play an important role in tumor pathogenesis and progression, and recent studies have demonstrated that a variety of forms, including interleukins (ILs) and transforming growth factor-beta(s) (TGF-beta(s)), may regulate tumors. In the present study, the expression of TGF-beta isoforms and ILs was investigated in cell lines from a rat osteosarcoma and a malignant fibrous histiocytoma (MFH), both established from transplantable tumors induced by 4-(hydroxyamino) quinoline 1-oxide (4-HAQO) in syngeneic F344 male rats. The results of a multiprobe RNase protection assay showed TGF-beta1 expression to be remarkably elevated, with no TGF-beta2 and beta3 detectable in MFH cells, while TGF-beta1 and -beta2 were found to be moderately and TGF-beta3 weakly expressed in osteosarcoma lines. All cell lines of osteosarcomas and MFHs expressed macrophage migration inhibitory factor at similar levels. In contrast to the lack of ILs in the MFH cells, moderate IL-6 and very weak IL-1beta expression was detected in the osteosarcoma cells. These results suggest that variation in expression pattern of these cytokines in osteosarcomas and MFHs might be involved in differences in histological appearance and biological behavior, including metastatic ability, between these two mesenchyme-derived tumor types.

Use of controlled mechanical stimulation in vivo to induce cartilage layer formation on the surface of osteotomized bone.

A micromachine was used to study the response of mesenchymal tissue to mechanically controlled motion in vivo. The middle portion of the coccygeal vertebra of Fischer 344 rats was osteotomized, and continuous bending motion was applied for 4 weeks. The experimental groups were divided into two groups with higher sliding displacement applied at the osteotomized gap of group II. Hyaline cartilage tissue was generated at the osteotomized ends, and was predominantly formed on the side that extended during the bending motion. These newly formed tissues stained intensively with safranin O and toluidine blue, positively with immunostain for type II collagen, but negatively with immunostain for type I collagen. Articular cartilage-like tissues with a surface and a layer structure were obtained in group II, in which higher sliding motion was applied. Light and electron microscopy revealed morphological features similar to those of normal articular cartilage tissue in the superficial and middle zones of the tissues obtained in group II. Collagen fibrils in the superficial zone were found aligned parallel to the smooth surface. Although tidemark formation was not observed in the deep zone, the structure was much more natural than that of any other tissue-engineered cartilage reported to date. These results suggest that controlled sliding stimulation can elicit the generation of articular cartilage structure in vivo.