Establishment and characterization of a KIT-positive and stem cell factor-producing cell line, KTHOS, derived from human osteosarcoma.

Osteosarcoma is a malignant bone tumor that commonly affects adolescents and young adults. In the present study a human osteosarcoma cell line, KTHOS, was established from a primary osteosarcoma lesion in the distal femur of a 16-year-old girl. After 106 passages, the KTHOS cell line retained the biological characteristics of osteosarcoma. The KTHOS cells had spindle to pleomorphic cytoplasm with round to ovoid nuclei containing multiple prominent nucleoli, as expected based on the mesodermic origin of osteoblasts. The KTHOS cells were immunoreactive for osteocalcin, osteonectin, stem cell factor (SCF), and KIT (CD117). Reverse transcriptase-polymerase chain reaction indicated that the KTHOS cell line expressed mRNA for SCF and KIT. The KTHOS cells produced relatively high amounts of soluble SCF as determined by enzyme-linked immunosorbent assay. The results suggest that cell proliferation of the KTHOS cell line might be involved in autocrine and/or paracrine loops of the SCF/KIT signaling system. The KTHOS cell line is a novel human osteosarcoma cell line that releases SCF and expresses KIT. This cell line can be used for studies to explore the mechanisms for oncogenesis of human osteosarcomas.

Expression of transforming growth factor beta isoforms and their receptors in malignant fibrous histiocytoma of soft tissues.

PURPOSE: Transforming growth factor beta (TGF-beta) is a multifunctional growth factor that variably affects proliferation, differentiation, and extracellular matrix formation. Little information is currently available on the TGF-beta expression in malignant fibrous histiocytoma (MFH). The aims of the present study were to investigate the expression of TGF-beta isoforms and their receptors in human MFH specimens. EXPERIMENTAL DESIGN: The expression of TGF isoforms, and TGF-beta receptors (TGF-beta R1 and -beta R2) were immunohistochemically evaluated in 43 paraffin-embedded MFH specimens. Furthermore, the correlation of the TGF-beta and receptor expression with tumor proliferative activity assessed by MIB-1 indices was analyzed. RESULTS: Positive immunoreactivity for TGF-beta1, -beta2, and -beta 3 was identified in tumor cells of 42, 40, and 38 of the 43 MFHs, respectively. In each TGF-beta isoform immunostaining, the specimens were divided into two groups based on the number of positive tumor cells: those with low (<25%) and those with high (>==25%) immunoreactivity. There were no statistically significant differences in the MIB-1 indices between the two groups. Positive immunoreactivity for TGF-beta R1 and -beta R2 was identified in tumor cells of 36 and 24 of the MFHs, respectively. The specimens were divided into two groups based on their receptor expression patterns: those with both TGF-beta R1- and -beta R2-positive immunoreactivity (n = 23), and those with both or either TGF-beta R1- and -beta R2-negative immunoreactivity (n = 20). The MIB-1 indices in the both-TGF-beta R1- and -beta R2-positive group were significantly higher than those in the other group (P = 0.0102). There was no significant difference in pulmonary metastasis ratios between the two groups. CONCLUSIONS: These findings strongly suggest an association of the TGF-beta ligand/receptor system with a significantly higher MIB-1 index in human MFHs. Investigation of the TGF-beta R1 and -beta R2 coexpression might be useful in predicting tumor behavior of MFHs.

Coexpression of hepatocyte growth factor and its receptor c-Met correlates with high MIB-1 proliferative index in malignant fibrous histiocytoma.

Hepatocyte growth factor (HGF) is a multifunctional cytokine that variably affects cell motility, proliferation, and morphogenesis. Little information is currently available on the HGF and its receptor c-Met expression in malignant fibrous histiocytoma (MFH). We immunohistochemically investigated the HGF and c-Met expression in 43 MFH tissue specimens. Furthermore, the correlation of the HGF and c-Met expression with tumor proliferative activity assessed by MIB-1 indices was analyzed. Our results showed that positive cytoplasmic immunoreactivity for HGF and c-Met was identified in tumor cells in 36 (84%) and 20 (47%) of the 43 MFH cases analyzed, respectively. Coexpression of HGF and c-Met was observed in 20 (47%) of the 43 MFHs, and was correlated with high MIB-1 proliferative indices (p = 0.0446). These findings strongly indicate that the HGF/c-Met signaling system plays an important role in promoting cell proliferation of human MFHs via an autocrine loop.

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.

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.

Neurilemmoma in the foot as a cause of heel pain: a report of two cases.

Two cases of deep-seated neurilemmoma that arose from plantar branches of the posterior tibial nerve and caused chronic heel pain are described. At the initial examination, one case was misdiagnosed as tarsal tunnel syndrome and the other was overlooked as plantar fasciitis; both cases were treated for long periods prior to operation. Deep-seated neurilemmomas in the foot can easily be overlooked and misdiagnosed as tarsal tunnel syndrome or plantar fasciitis because of the rarity, absence of palpable mass, and similarity of symptoms to those of other frequently encountered foot disorders. Magnetic resonance imaging provides the best modality for differential diagnosis. In the present cases, surgical excision of the tumors resulted in immediate and complete relief of chronic heel pain. Surgeons should consider neurilemmoma as a cause of persistent chronic heel pain despite the rarity of the disease.

Periosteal osteoblastoma of the distal femur.

Osteoblastomas located on the surface of the cortical bone, so-called periosteal osteoblastomas, are extremely rare. We report on a case of periosteal osteoblastoma arising from the posterior surface of the right distal femur in a 17-year-old man. Roentgenographic, computed tomographic, magnetic resonance imaging, and histologic features of the case are presented. Periosteal osteoblastoma should be radiologically and histologically differentiated from myositis ossificans, avulsive cortical irregularity syndrome, osteoid osteoma, parosteal osteosarcoma, periosteal osteosarcoma, and high-grade surface osteosarcoma. Although periosteal osteoblastoma is rare, this tumor should be included in the differential diagnosis of surface-type bone tumors.

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.

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.

Extraabdominal desmoid tumor in a surgical scar of a patient with Sprengel's deformity.

Patients with an extraabdominal desmoid tumor have multiple minor bone abnormalities. The authors describe a rare case of an extraabdominal desmoid tumor that developed in a scar 2 years after surgery for Sprengel's deformity of the right shoulder in an 8-year-old girl. The association between the tumor and Sprengel's deformity has never been reported previously. Antecedent surgical trauma might play a role in the development of this tumor.

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.

Multimodality imaging features of primary xanthoma of the calcaneus.

Secondary xanthomatous features are histologically observed in various bone lesions, but primary xanthoma of bone is rare. We present a primary xanthoma of the right calcaneus in a 51-year-old woman who had no aberrant lipid metabolism. Roentgenograms showed a small osteolytic lesion in the calcaneal triangle, partially surrounded by bone sclerosis. Computed tomographic scans of the calcaneus showed multiple osteolytic areas, with an irregular trabecular pattern in the surrounding sclerotic bone. T1-weighted magnetic resonance images showed a lesion with central low signal intensity, surrounded by a peripheral ring with high signal intensity. The entire lesion showed high signal intensity on T2-weighted images, partially surrounded by areas with low signal intensity, concordant with reactive bone sclerosis. Histologically, the lesion consisted of numerous lipid-laden histiocytes arranged in sheets, scattered multinucleated giant cells and lymphocytes, and granulation tissues. There was no evidence of pre-existing lesions. Total excision of the tumor was curative.

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.

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.

Fine-needle aspiration biopsy of solid aneurysmal bone cyst in the humerus.

We report the fine-needle aspiration biopsy (FNAB) cytology findings of a solid aneurysmal bone cyst in the left humerus of a 69-yr-old woman. Radiographically, the lesion showed an extensive, relatively well-defined osteolysis in the diaphysis, with a pathologic fracture. FNAB smears of the lesion consisted of benign, mononuclear cells and numerous osteoclast-like multinucleated giant cells. Some clusters of the mononuclear cells were closely associated with dense, homogeneous, extracellular, matrix material. To our knowledge, the FNAB features of solid ABC of the long bones have not been described previously in the English-language literature. The cytologic features are indistinguishable from those of giant cell tumors of bone and brown tumors of hyperparathyroidism.