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Tetsuji Yamamoto

Publications and source records attributed to Tetsuji Yamamoto.

70 records · Page 4Linked to original sources
PubMedDate not supplied

Tarsal tunnel syndrome caused by epineural ganglion of the posterior tibial nerve: report of 2 cases and review of the literature.

Ganglia within the posterior tibial nerve is a rare condition. The authors report 2 cases of epineural ganglion of the posterior tibial nerve, causing tarsal tunnel syndrome. Both cases presented with numbness on the plantar surface of the foot. Magnetic resonance imaging showed the presence of the cyst within the tarsal tunnel. During surgery, these cysts were found within the epineurium of the posterior tibial nerve and were successfully removed without damage to nerve fibers. Both patients were free of symptoms after surgery. Ganglion cysts in the peripheral nerve are either intrafascicular or epineural. Intrafascicular ganglia present beneath the epineurium and involve the nerve fibers, whereas epineural ganglia are located in the epineurium and do not involve the nerve fibers. A review of the literature discusses these concepts. The authors suggest that epineural ganglion should be clinically distinctive from an intrafascicular ganglion because of the differences in surgical treatment, postoperative nerve function, and the recurrence rate.

Adult↗
PubMedDate not supplied

Synovial osteochondromatosis of the Lisfranc joint: a case report.

Synovial osteochondromatosis arising in the foot is a rare condition. We report a 69-year-old woman with synovial osteochondromatosis of the Lisfranc joint. The patient presented with a 10-year history of left foot pain. Imaging studies showed multiple calcified masses around the Lisfranc joint. We performed a synovectomy and removal of the loose bodies in the dorsal, lateral, and plantar aspects of the Lisfranc joint by dislocating the bases of the fourth and fifth metatarsal bones. To our knowledge, this is only the second case report of synovial osteochondromatosis involving the Lisfranc joint.

Aged↗
PubMedDate not supplied

A true intra-articular lipoma of the knee in a girl.

A 16-year-old girl presented with a soft-tissue mass in the anterolateral aspect of her right knee. Magnetic resonance imaging revealed an intra-articular tumor arising from the anterior fat pad of the knee. The tumor showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. It was resected under arthroscopic guidance. Grossly, the tumor was composed of soft, yellowish adipose tissue. Pathologic examination revealed a collection of mature adipocytes with marked myxoid changes in the matrix. A diagnosis of lipoma was made. True intra-articular lipomas should be distinguished from lipoma arborescens, which is considered to be a reactive process. In the English language literature, we found only 7 cases of true intra-articular lipoma reported previously. The present case is the youngest patient with such a tumor, and all the previous reports are of the tumor in adult patients. Intra-articular lipoma should be considered in the differential diagnosis of intra-articular masses in adolescents.

Adolescent↗
PubMedDate not supplied

Scrape and fine-needle aspiration cytology of elastofibroma.

BACKGROUND: Cytological findings of elastofibroma have rarely been reported and, to the best of our knowledge, have been illustrated in only 4 patients in the English language literature. MATERIALS AND METHODS: We retrospectively reviewed fine-needle aspiration biopsy (FNAB) and scrape smears in 5 cases of elastofibroma. RESULTS: All the lesions were typically located between the rib cage and the scapula. The cytological smears consisted of mature adipocytes, fibroblasts, collagen fibers, globular bodies and characteristic "braid-like" or "fern-like" structures, revealing degenerative elastic fibers. All the smears were specifically diagnosed as elastofibroma in combination with clinical and radiological findings. CONCLUSION: FNAB smears of elastofibromas may be hypocellular due to their densely fibrous nature and therefore diagnostic material may often be overlooked. Careful evaluation of the background of the smears coupled with full knowledge of the clinical and radiological findings, including magnetic resonance imaging, is required to establish the correct diagnosis.

Adipocytes↗
PubMedDate not supplied

Reimplantation of autoclaved or irradiated cortical bones invaded by soft tissue sarcomas.

BACKGROUND: Bone defects after excision of malignant bone and soft tissue tumors are usually reconstructed by autogenous bone grafting or allografting. PATIENTS AND METHODS: We treated 2 patients who had soft tissue sarcomas with bone involvement, the first by excision and reimplantation of the hemicortical autogenous cortical bone graft after autoclaving and the second with intraoperative irradiation. RESULTS: In both patients, postoperative follow-up radiographic studies showed incorporation of the implanted bones into the host bones within 12 months. Biopsy of the implanted bone performed 3 years after surgery showed many viable osteocytes, and blood vessel invasion into Harversian canals. No complications regarding the reconstructive techniques were observed during the postoperative period. CONCLUSION: The reimplantation of autogenous cortical bones after autoclaving or irradiation is a useful reconstructive method for partial bone defects in soft tissue tumor surgery.

Adult↗
PubMedDate not supplied

Fine-needle aspiration biopsy in the initial diagnosis of bone lesions.

BACKGROUND: The diagnostic role of fine-needle aspiration biopsy (FNAB) of bone lesions is not yet fully understood. The aim of this study was to examine the diagnostic accuracy and reliability of FNAB of bone lesions. MATERIALS AND METHODS: FNAB smears of 73 lesions obtained from 70 patients with bone lesions were retrospectively reviewed randomly, combined with clinical and radiological findings. RESULTS: Of the 73 FNAB cases analyzed, 67 (92%) were considered to be adequate for diagnosis. The sensitivity and specificity were 100% and 86%, respectively. The positive and negative predictive values were 94% and 100%, respectively. The specific FNAB diagnoses were correct in 63% of the benign group, 89% of the malignant group and 17% of the nonneoplastic group. CONCLUSION: FNAB of bone is a simple, safe, rapid, reliable and cost-effective diagnostic procedure. FNAB is suggested to be helpful in the workup and management of patients with bone lesions.

Adolescent↗
PubMedDate not supplied

Management of liposarcoma occurring in pregnant women.

BACKGROUND: The coexistence of pregnancy and liposarcoma is rare. Only 12 cases of pregnancy-associated liposarcoma have previously been reported in the English-language literature. MATERIALS AND METHODS: We present two cases of liposarcoma occurring in pregnant patients: one myxoid liposarcoma in a 29-year-old woman at 29 weeks' gestation; another well-differentiated liposarcoma in a 44-year-old woman at 22 weeks' gestation. RESULTS: The first patient's infant was delivered by cesarean section after the confirmation of pulmonary maturity of the fetus. The patient was subsequently treated with chemotherapy and radiotherapy. The second patient awaited delivery until 32 weeks' gestation with no treatment of the tumor because she had a low-grade sarcoma. After cesarean section, surgical treatment followed. CONCLUSION: Treatment of sarcomas occurring during pregnancy is difficult. Both mother and fetus should be appropriately managed, depending on the trimester at the time of diagnosis and the histological type and grade of the tumor.

Adult↗
PubMedDate not supplied

Expression of stem cell factor and c-kit in human malignant fibrous histiocytoma cell line (TNMY1).

BACKGROUND: The expression of c-kit and/or its ligand, stem cell factor (SCF), has been related to tumor proliferation, in several tumor systems. MATERIALS AND METHODS: We analyzed the expression of the SCF/its receptor (c-kit) mRNA and the production of soluble SCF in a human malignant fibrous histiocytoma (MFH) cell line (TNMY1). RESULTS: Immunocytochemical analysis revealed that the TNMY1 cells were positive for both SCF and c-kit. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed that the TNMY1 cell line expressed mRNA for SCF and c-kit. By using an enzyme-linked immunosorbent assay (ELISA), the TNMY1 cells were found to produce relatively high amounts of soluble SCF. However, the addition of soluble SCF to the TNMY1 cells did not alter the in vitro growth ability of the cells. CONCLUSION: Our data showed that the MFH cells produced consistent amounts of SCF but did not demonstrate autocrine growth modulation. Thus, SCF secretion may have a paracrine activity in the growth of MFH cells.

Cell Division↗
PubMedDate not supplied

Expression of stem cell factor and lack of c-kit expression in malignant fibrous histiocytoma of soft tissues.

BACKGROUND: Little information is available on the expression of stem cell factor (SCF) and its receptor c-kit in soft tissue tumors of a fibrohistiocytic origin, including malignant fibrous histiocytoma (MFH). MATERIALS AND METHODS: We investigated the endogenous expression of SCF and c-kit in 43 MFH tissue samples using immunohistochemical techniques. Furthermore, we examined the correlation of SCF expression in MFHs with proliferative activity assessed by mitotic indices and MIB-1 immunohistochemical staining. RESULTS: Positive immunoreactivity for c-kit was identified in tumor cells of only one MFH case, while the remaining 42 cases were negative. In the one positive case, immunohistochemical staining was focal. Positive immunoreactivity for SCF was identified in 31 out of 43 cases studied (72%, focal; 11, moderate; 6, diffuse; 14). There were no significant differences in the MIB-1 and mitotic indices between the SCF-positive and negative groups. CONCLUSION: Our data indicate that any direct autocrine effects of the SCF/c-kit system on cell growth regulation are precluded in most MFH cases studied, but it is speculated that SCF might indirectly influence tumor growth by promoting local neovascularization.

Cell Division↗
PubMedDate not supplied

Immunohistochemical analysis of platelet-derived growth factor and its receptors in soft tissue malignant fibrous histiocytoma.

BACKGROUND: Little information is available regarding the expression of platelet-derived growth factor (PDGF) isoforms and their receptors in soft tissue malignant fibrous histiocytoma (MFH). MATERIALS AND METHODS: We investigated expression of PDGF isoforms and their receptors (PDGF-R alpha and -R beta) in 43 MFH tissue specimens using immunohistochemical techniques. Furthermore, we examined the correlation of PDGF expression in MFHs with proliferative activity assessed by MIB-1 immunohistochemical staining. RESULTS: Positive cytoplasmic immunoreactivity for PDGF-AA, -BB and -AB was identified in tumor cells of 28 (66%), 4 (10%) and 26 (61%), respectively, of the 43 MFHs analyzed. Positive cytoplasmic immunoreactivity for PDGF-R alpha and -R beta was identified in tumor cells of 41 (95%) and 32 (74%), respectively, of the MFHs. Thirty-four (79%) MFHs coexpressed one or more PDGF isoforms and their corresponding receptors. In PDGF-AA immunostaining, MIB-indices in the high immunoreactivity group (> 10% of tumor cells) were significantly higher than those in the low immunoreactivity group (< 10% of tumor cells) (p = 0.031). CONCLUSION: Our data provide evidence to support the presence of an autocrine/paracrine mechanism of proliferation control involving the PDGF ligand/receptor system in human MFHs.

Adolescent↗
PubMedDate not supplied

Amphiregulin and epidermal growth factor receptor expression in human malignant fibrous histiocytoma of soft tissues.

BACKGROUND: Amphiregulin is a member of the epidermal growth factor (EGF) system and a potent mitogen for various epithelial tissues. Little information, however, is currently available on the amphiregulin and EGF receptor (EGF-R) expression in mesenchymal malignancies of a fibrohistiocytic origin including malignant fibrous histiocytoma (MFH). MATERIALS AND METHODS: We investigated the amphiregulin and EGF-R expression in 43 human MFH tissues using immunohistochemical techniques. Furthermore, the correlation of the ligand and the receptor expression with tumor proliferative activity assessed by MIB-1 indices was analyzed. RESULTS: Positive immunoreactivity for amphiregulin and EGF-R was identified in 34 (79%) and 36 (84%) of the 43 MFH cases analyzed, respectively. Coexpression of amphiregulin and EGF-R was observed in 30 (70%) of the 43 MFHs analyzed. There were no significant differences in MIB-1 indices between both the amphiregulin and EGF-R-positive MFHs and the remaining MFHs. CONCLUSION: These results show that amphiregulin is expressed not only by epithelial tumor cells but also by MFH cells. Our data provide evidence indicating the presence of an autocrine mechanism of proliferation control involving the amphiregulin/EGF-R signaling system in human MFHs.

Adolescent↗
PubMedDate not supplied

Expression of betacellulin, heparin-binding epidermal growth factor and epiregulin in human malignant fibrous histiocytoma.

BACKGROUND: Heparin-binding epidermal growth factor (HB-EGF), betacellulin (BTC) and epiregulin (EPR) are members of the EGF system and involved in the cell growth of various epithelial malignancies. There have been no reports on the HB-EGF, BTC and EPR expression in mesenchymal malignancies of fibrohistiocytic origin including malignant fibrous histiocytoma (MFH). MATERIALS AND METHODS: We investigated the expression of HB-EGF, BTC, EPR and EGF-receptor (EGF-R) in 43 human MFH tissue samples using immunohistochemical techniques. RESULTS: Positive immuno-reactivity for HB-EGF, BTC, EPR and EGF-R was identified in 28 (65%), 7 (16%), 43 (100%) and 36 (84%) out of the 43 MFH cases analyzed, respectively. Coexpression of HB-EGF/BTC, BTC/EPR and HB-EGF/EPR was observed in 6 (14%), 7 (16%) and 28 (65%) of the MFHs, respectively. Coexpression of HB-EGF/EGF-R, BTC/EGF-R and EPR/EGF-R was observed in 25 (58%), 6 (14%) and 36 (84%) of the MFHs, respectively. CONCLUSION: These results revealed that HB-EGF, BTC and EPR are expressed not only by epithelial tumor cells, but also by MFH cells. It is suggested that HB-EGF and EPR might be more important tumor growth regulators of MFH through autocrine or paracrine pathways, when compared with BTC.

Adolescent↗
PubMedDate not supplied

Inhibitory effect of STI571 on cell proliferation of human malignant fibrous histiocytoma cell lines.

BACKGROUND: Malignant fibrous histiocytoma (MFH) is one of the most common high-grade sarcomas in bone and soft tissue and, due to its chemo-resistance, the prognosis of the disease is poor. ST1571 is a tyrosine kinase inhibitor that was initially developed as a BCR/ABL inhibitor for chronic myeloid leukemia patients. STI571 also selectively inhibits platelet-derived growth factor receptors (PDGFRs) and c-kit. We examined the expression of PDGFRs and c-kit in human MFH cell lines, and the effect of STI571 on cell proliferation. MATERIALS AND METHODS: Four human MFH cell lines (TNMY1, GBS-1, Nara-F and Nara-H) were used. mRNA expression of the receptor tyrosine kinases (PDGFRs and c-kit) was analyzed using reverse transcription-polymerase chain reaction, and the inhibitory effect of STI571 on cell proliferation was analyzed using the MTS assay technique. RESULTS: PDGFRalpha mRNA was expressed in TNMY1 and GBS-1, and PDGFRbeta and c-kit mRNAs were expressed in TNMY1, GBS-1 and Nara-F. All three of these mRNAs were absent in Nara-H. STI571 inhibited cell proliferation of TNMY1, GBS-1 and Nara-F in a dose- and time-dependent manner, but cell proliferation of Nara-H was not inhibited by ST1571 at concentrations of 10 microM or less. CONCLUSION: STI571 significantly inhibited proliferation of the three human MFH cell lines that expressed mRNAs of target receptor tyrosine kinases. The inhibitory effect of ST1571 on cell proliferation in these three cell lines might be due to decreased tyrosine kinase activity. STI571 might be a potent chemotherapeutic agent for human MFHs.

Benzamides↗
PubMedDate not supplied

Expression of VEGF and its receptors and angiogenesis in bone and soft tissue tumors.

BACKGROUND: Tumor angiogenesis and vascularization are essential requirements for the growth and metastasis of tumors. There is evidence that overexpression of the vascular endothelial growth factor (VEGF) is correlated with an adverse prognosis in some tumors. The expression of VEGF, its receptors and microvessel density (MVD) of bone and soft tissue tumors was evaluated. MATERIALS AND METHODS: Tissue specimens of 60 patients including 30 malignant and 30 benign tumors confirmed by biopsy were examined. Expression of VEGF and its receptors (flt-1 and KDR/flk-1) was observed by immunohistochemistry. Tumor angiogenesis was assessed morphologically by measuring intratumoral MVD. RESULTS: Semi-quantitative evaluation of immunoreactivity showed that VEGF was significantly higher in malignant tumors than in benign tumors. A correlation was found between the immunoreactivity of VEGF and KDR. Moreover, correlations were found either between MVD and VEGF or between MVD and KDR/flk-1. CONCLUSION: Signal transduction, in particular by VEGF and KDR, potentially contributes to the angiogenesis of bone and soft tissue tumor.

Bone Neoplasms↗