Differentiation between neurofibromas and malignant peripheral nerve sheath tumors in neurofibromatosis 1 evaluated by MRI.

PURPOSE: The imaging discrimination between neurofibroma (NF) and malignant peripheral nerve sheath tumor (MPNST) is clinically very important. The purpose of this study is to define the criteria for the differential diagnosis between NF and MPNST on MRI in neurofibromatosis 1 (NF1). METHODS: A total of 37 patients with NF1, 18 NFs and 19 MPNSTs were evaluated by MRI at 1.5 T. Magnetic resonance imaging (MRI) findings were compared using univariate and multivariate analyses. RESULTS: The MRI findings characteristic of MPNST (p < 0.05) were an irregular tumor shape (15/19 in MPNST vs. 5/18 in NF), unclear margin (13/19 in MPNST vs. 6/18 in NF), intra-tumoral lobulation (12/19 in MPNST vs. 3/18 in NF), presence of high signal-intensity area on T1-weighted images (T1WI) (12/19 in MPNST vs. 1/18 in NF), no target sign (0/19 in MPNST vs. 12/18 in NF), inhomogeneous enhancement on contract-enhanced T1WI (17/18 in MPNST vs. 9/16 in NF) and a lower rate of enhanced area (54% in MPNST vs. 87% in NF) were critical indicators to differentiate MPNST from NF. A multivariate analysis showed that intra-tumoral lobulation and the presence of a high signal-intensity area on T1WI were considered to be diagnostic indicators of MPNST. The sensitivity and specificity for these two items were 63.2, 83.3, 63.2 and 87.5%, respectively. CONCLUSION: MRI shows features which were helpful for differentiating MPNST from NF.

Frequent expression of smooth muscle markers in malignant fibrous histiocytoma of bone.

BACKGROUND/AIMS: Malignant fibrous histiocytoma (MFH) of bone, a relatively rare primary malignant bone tumour, is a distinct clinicopathological entity as opposed to MFH derived from soft tissue. Although the true histogenesis of this condition is still controversial, a considerable number of cases of MFH in soft tissue show positive immunohistochemical reactivity for muscle markers such as desmin, common muscle actin (HHF35), and alpha smooth muscle actin (SMA), suggesting that MFH cells are myofibroblastic in nature. METHODS: This study investigated immunoreactivity for several different muscle markers in 19 cases of MFH of bone together with reverse transcription polymerase chain reaction (RT-PCR) analysis on frozen tissue samples that were available in four cases, and compared the data with those found in 11 cases of osteosarcoma and 11 cases of soft tissue MFH treated over the same period. RESULTS: Immunohistochemistry revealed that MFH of bone showed relatively frequent expression of smooth muscle markers, including calponin (nine cases), alpha-SMA (nine cases), and SM22alpha (18 cases), and this was confirmed by RT-PCR analysis. However, only one, two, and three cases of MFH of bone showed positive staining for desmin, MyoD1, and HHF35, respectively. Similarly, 11 osteosarcoma cases were relatively frequently positive for alpha-SMA (five cases), calponin (four cases), and SM22alpha (seven cases), and less frequently positive for desmin (one case), MyoD1 (none), and HHF35 (none). In contrast, very few MFH of soft tissue cases (n = 11) showed positive reactivity for all of these muscle markers. It has recently been reported that human bone marrow stromal cells also express various kinds of smooth muscle markers including alpha-SMA and calponin. CONCLUSIONS: These results suggested that MFH of bone may derive from mesenchymal stromal cells in bone marrow and has a more myofibroblastic differentiation than soft tissue MFH.

Malignant mesenchymoma of the lower leg.

A 24 year old man had a two year history of a painless mass on his right popliteal region. Magnetic resonance imaging demonstrated a 6 x 8 cm tumour mass in the lateral gastrocnemius. Histological examination of the tumour resected by radical surgery revealed that it consisted of myoblastic sarcoma and chondrosarcoma. Immunohistochemical studies were positive for Ki-67 and p53 throughout the area and for S-100 protein in the chondrosarcomatous area; in addition, they showed partial positivity for muscle common actin (HHF-35), smooth muscle actin, and myoglobin in the spindle cells. The percentages of Ki-67, p53, and p21/WAF1 positive cells in the spindle cell component were 34%, 65.7%, and < 0.1%, respectively. In addition, staining was negative for pancytokeratin, desmin, and glial fibrillary acidic protein. The SYT-SSX, TLS-CHOP, and EWS-FLI1 fusion genes were not detected using the reverse transcription polymerase chain reaction. Given the results, the definitive histological diagnosis is malignant mesenchymoma. This is the first report of malignant mesenchymoma of the lower leg with immunohistochemical and molecular studies.

In vivo inhibition of tumour growth by dexamethasone in murine osteosarcomas.

This study was performed to determine whether glucocorticoid (GC) is an effective inhibitor of tumour growth in murine osteosarcoma (OS) in vivo. The effects of dexamethasone (DEX) on the growth of this tumour were studied in male C3H/He mice. The animals received a dose of 1.25 or 5 microg/g of DEX in 0.1 ml of steroid solution daily intraperitoneally (i.p.) for 14 days. In each DEX-treated group, significant inhibition of the tumour growth curve was seen in a dose- dependent manner compared with the control group (P<0.0001). The percentage of proliferative cell nuclear antigen (PCNA)-positive cells was 22.7% in the 5 microg/g DEX treatment group compared with 67.6% in the control group (P=0.009). Furthermore, mifepristone, a GC receptor antagonist, blocked the inhibition of tumour growth induced by DEX. In the control group, tumour cells showed positive reactivity for nuclear glucocorticoid receptors (GR) by immunohistochemistry. The results of this study indicate that tumour growth inhibition by DEX in murine osteosarcoma may be via GR.

Intramuscular haemangioma adjacent to the bone surface with periosteal reaction. Report of three cases and review of the literature.

We present three cases of intramuscular haemangioma adjacent to bone in the lower limb. All patients had local pain during the third decade. Plain radiographs showed an irregular or hypertrophic periosteal reaction on the shaft of the fibula and an intramuscular mass adjacent to the bone with inhomogeneous high signal intensity on MRI. These lesions mimic periosteal or parosteal tumours.

Malignant hemangiopericytoma of the breast.

A55-year-old woman presented with 1-year history of mass in the right breast. Incisional biopsy showed the tumor to be malignant hemangiopericytoma from its histology. The tumor showed low--intermediate density and peripheral contrast enhancement on CT, and inhomogeneous mixed-signal intensity both on T1W and T2W images, and peripheral enhancement with Gd-DTPA on MRI with no invasion of the duct.

Intraoperative extracorporeal autogenous irradiated bone grafts in tumor surgery.

There are several procedures for reconstruction of bony defects after resection of malignant musculoskeletal tumors. The clinical results of intraoperative extracorporeal autogenous irradiated bone grafts in 20 patients with musculoskeletal tumors are discussed. The authors' method of treatment consists of: (1) wide en bloc resection of the tumor with involved bone; (2) curettage of the tumor from the resected bone; (3) extracorporeal irradiation with 50 Gy as a bolus single dose to the isolated bone; and (4) reimplantation of the irradiated bone into the host with fixation devices. Twelve bone sarcomas and eight soft tissue sarcomas with bone involvement were treated surgically with this reconstruction method after wide resection of the tumors. The irradiated bone was used as an intercalary graft in seven cases, as an osteoarticular graft in 11 cases, and as a hemicortical graft in two cases. The theoretical advantages of this method are certain sterilization of tumor cells with radiation, easy availability and good adaptation of size and shape, no risk of disease transmission, preservation of bone stock and ligamentous tissue, and no immunologic reaction. Radiologically, bony union occurred in 23 of 29 (79%) osteotomy sites. The overall radiographic evaluation rating was 74% and the functional rating was 73% according to the International Society of Limb Salvage rating system. Nonunion (20%) and infection (15%) were the two major complications. Preservation of the tendon insertions and ligamentous structures of the irradiated bone seemed to restore excellent joint function. No local recurrence was detected from the irradiated bones during the mean followup of 45 months. These results indicate intraoperative extracorporeal irradiated bone graft can be a widely applicable method for reconstruction in tumor surgery.

Plexiform schwannoma of the foot.

The present report describes a plexiform schwannoma involving the subcutis of the foot in an 8-year-old boy. Gross findings revealed thin fibrous septa in a multilobulated tumor that was partly separated into free body-like nodules in the subcutis. Preoperative CT and MRI failed to delineate this multinodular architecture or free bodies. This is a case presentation including the CT and MR findings associated with plexiform schwannoma.

Chromosome rearrangement at 17q25 and xp11.2 in alveolar soft-part sarcoma: A case report and review of the literature.

BACKGROUND: Despite the characteristic histopathologic appearance of alveolar soft-part sarcoma (ASPS), its histogenesis remains unclear, and cytogenetic analysis of ASPS is limited to eight cases so far because of the extreme rarity of this disease. METHODS: The authors document a cytogenetic study of a primary case of ASPS in which a modern spectral karyotyping technique was used. RESULTS: A standard cytogenetic analysis of the primary tumor cells with G-banding revealed 46,XY, add(17)(q25) in 23 of 25 metaphases analyzed. This structural rearrangement of chromosome 17, involving band q25, was also present in 5 of 8 ASPS cases in the literature. Moreover, with the spectral karyotyping technique, the additional part of the long arm of chromosome 17 in the current case was found to originate from chromosome X, resulting in a final tumor karyotype of 46, XY, add(17)(q25).ish der(17)t(X;17) (p11.2;q25)(wcpX+). CONCLUSIONS: This case report documents a clonal chromosome abnormality of der(17)t(X;17)(p11.2;q25) in ASPS. The results of the current study indicate that further molecular analyses focused on 17q25 and Xp11.2 are of interest and could help to elucidate the pathogenesis of ASPS.

Ossifying intramuscular metastasis from colon cancer: report of a case.

PURPOSE: This report presents a patient who developed severe buttock pain because of an ossified intramuscular metastasis from a sigmoid colon cancer. METHODS: This is a case report and review of the literature for intramuscular metastasis from colon cancer. RESULTS: Computed tomography and magnetic resonance imaging showed a soft-tissue mass with heavy calcification. Histologically, mature compact bone was observed with adenocarcinoma cells dispersed among the bony trabeculae. CONCLUSION: When an intramuscular mass is seen, even if it contains extensive calcification, metastasis from colon cancer should be included in differential diagnosis.

Granular cell tumor of the subcutis: CT and MRI findings. A report of three cases.

Three cases of granular cell tumor (GCT) of the subcutis are presented. Computed tomography showed a mass isodense with muscle with an ill-defined margin. Magnetic resonance imaging showed a mass with inhomogeneous low signal intensity on both T1- and T2-weighted-images. Another characteristic feature of subcutaneous GCT is its attachment in part to muscle. Histological examination confirmed the diagnosis in all cases.

Expression of smooth muscle calponin in synovial sarcoma.

Purpose. Histogenesis of synovial sarcoma remains controversial and reliable molecular markers for diagnosis are necessary. Expression of basic calponin, a smooth muscle differentiation-specific actin-binding protein, was studied in synovial sarcoma.Subjects and Methods. The basic calponin gene and the gene product were analyzed by reverse transcription PCR analysis (RT-PCR) and immunohistochemistry in 14 synovial sarcomas and a human synovial sarcoma cell line (HS-SY-II).Results and Discussion. Immunoreactivity for basic calponin was detected in the cytoplasm of 6 synovial sarcomas (43% positive). In the basic calponin-positive tumors and the HS-SY-II cells, expression for smooth muscle-specific genes, including basic calponin and SM22alpha , was detected by RT-PCR, suggesting a lineage relationship between synovial sarcoma cells and smooth muscle-like mesenchymal cells.Conclusions. A subset of synovial sarcomas expressing the basic calponin gene and the gene product were identified. The basic calponin may have potential utility as a novel molecular marker identifying certain synovial sarcomas.

Surgical treatment for skeletal metastases from soft tissue sarcomas: experience with 23 lesions in 20 patients.

Purpose. This paper reports the procedures and the clinical results of a series of surgical treatments for skeletal metastases from soft tissue sarcomas.Subjects and methods. Surgical treatment of metastatic bony lesions from soft tissue sarcomas has been carried out over a 20 year period (1975-1996). Thirty-two patients developed skeletal metastases from soft tissue sarcomas, and 20 of these cases received surgical treatment. The 23 metastatic bony lesions in these 20 patients were treated using the following surgical approaches: wide resection with prosthetic replacement in five lesions, wide or marginal resection without reconstruction in four lesions, intramedullarly nailing with curettage and methylmethacrylate cementation in four lesions, marginal resection of vertebral body with replacement by a ceramic prosthesis in three lesions, laminectomy in three lesions, intramedullarly nailing in two lesions, and curettage in two lesions.Results. Relief of pain was achieved in 17 of the 20 patients. The ambulatory status of the patients with metastasis in the lower extremity or periacetabular region was significantly improved in nine of 10 cases. Seventeen patients died of disease, with a mean survival period of 17.9 months after surgery for metastasis.Discussion. Although surgical treatment for skeletal metastases from soft tissue sarcomas cannot save the life of the patient, it can be of value in improving their well-being and overall quality of life. In these cases, surgical intervention may be more frequently indicated than in tumors with an osteoblastic or mixed pattern.