Yoji Shido

MRI Features in the Differentiation of Malignant Peripheral Nerve Sheath Tumors and Neurofibromas

OBJECTIVE The objective of this study was to identify the MRI criteria that best differentiate malignant peripheral nerve sheath tumors from benign neurofibromas. MATERIALS AND METHODS We retrospectively analyzed MR images obtained for 41 histologically diagnosed cases of malignant peripheral nerve sheath tumor and 20 cases of neurofibroma that had been treated at four tertiary institutions. Twenty of the patients with malignant peripheral nerve sheath tumors and 14 patients with neurofibromas developed the disease in association with neurofibromatosis 1. The MR images were evaluated with regard to tumor size, signal intensity, heterogeneity of T1- and T2-weighted MR images, enhancement pattern, definition of margins, presence of perilesional edemalike zone, and presence of intratumoral cystic lesions. RESULTS Significant differences between malignant peripheral nerve sheath tumors and neurofibromas were noted for the largest dimension of the mass, peripheral enhancement pattern, perilesional edemalike zone, and intratumoral cystic lesion. In cases associated with neurofibromatosis 1, heterogenicity on T1-weighted images was also significant in differentiating neurofibroma from malignant peripheral nerve sheath tumor. The presence of two or more of the four features suggestive of malignancy indicated malignant peripheral nerve sheath tumor with a sensitivity of 61% and a specificity of 90%. CONCLUSION The MR features described in this study are useful for distinguishing malignant peripheral nerve sheath tumors from neurofibromas. If a tumor has two or more of the four statistically significant features, it can be considered to be highly suspicious of malignancy and should be subjected to a biopsy for early diagnosis.

Clinical Outcome of Sacral Chordoma With Carbon Ion Radiotherapy Compared With Surgery

PURPOSE To evaluate the efficacy, post-treatment function, toxicity, and complications of carbon ion radiotherapy (RT) for sacral chordoma compared with surgery. METHODS AND MATERIALS The records of 17 primary sacral chordoma patients treated since 1990 with surgery (n = 10) or carbon ion RT (n = 7) were retrospectively analyzed for disease-specific survival, local recurrence-free survival, complications, and functional outcome. The applied carbon ion dose ranged from 54.0 Gray equivalent (GyE) to 73.6 GyE (median 70.4). RESULTS The mean age at treatment was 55 years for the surgery group and 65 years for the carbon ion RT group. The median duration of follow-up was 76 months for the surgery group and 49 months for the carbon ion RT group. The local recurrence-free survival rate at 5 years was 62.5% for the surgery and 100% for the carbon ion RT group, and the disease-specific survival rate at 5 years was 85.7% and 53.3%, respectively. Urinary-anorectal function worsened in 6 patients (60%) in the surgery group, but it was unchanged in all the patients who had undergone carbon ion RT. Postoperative wound complications requiring reoperation occurred in 3 patients (30%) after surgery and in 1 patient (14%) after carbon ion RT. The functional outcome evaluated using the Musculoskeletal Tumor Society scoring system revealed 55% in the surgery group and 75% in the carbon ion RT group. Of the six factors in this scoring system, the carbon ion RT group had significantly greater scores in emotional acceptance than did the surgery group. CONCLUSION Carbon ion RT results in a high local control rate and preservation of urinary-anorectal function compared with surgery.

Successful Treatment With Meloxicam, a Cyclooxygenase-2 Inhibitor, of Patients With Extra-Abdominal Desmoid Tumors: A Pilot Study

TO THE EDITOR: Extra-abdominal desmoid tumors, which are usually sporadic in nature, occur across a wide age range and can arise at virtually any body site, but are mainly found in the extremities and girdles, chest, abdominal wall, and neck. Local growth and invasion may result in pain, deformity, and functional impairment. The potential morbidity of surgery and radiation therapy has led investigators to assess the role of noncytotoxic and cytotoxic chemotherapy. Because extra-abdominal desmoid tumors rarely cause disease-specific death, pharmacologic treatment with fewer complications is desirable. Cyclooxygenase-2 (COX-2) is implicated as a factor in tumor initiation in colonic neoplasia and has also been demonstrated to play a role in the growth of desmoid tumors, with pharmacologic blockade of COX resulting in decreased cell proliferation in desmoid cell cultures in vitro, and COX-2 blockade resulting in smaller desmoid tumors in an in vivo mouse model. Taken together, these results led us to hypothesize that COX-2 might represent an attractive therapeutic target in desmoid tumors, and that meloxicam may have a marked efficacy compared with conventional nonselective nonsteroidal anti-inflammatory drugs. Between 1991 and 2003, excluding those with intra-abdominal, familial adenomatous polyposis–associated, and unresectable tumors, 30 patients were treated with surgery in our institutions. Because the recurrence rate of this group was high (53%) even with a mostly negative surgical margin, since 2003, 22 consecutive extra-abdominal patients have been prospectively treated with meloxicam. Patients with intra-abdominal desmoid tumors and patients less than 16 years of age were excluded. Meloxicam was administered orally at 10 mg/ day. There were no patients with a known history of gastritis or gastric ulcer, and none were receiving hormonal medications. Baseline imaging of desmoid tumors by MRI was obtained before starting treatment. Patients treated with meloxicam have been followed with physical examinations and magnetic resonance imaging and/or computed tomography at the outpatient unit of our department of orthopedic surgery every 3 to 6 months. The efficacy of meloxicam was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) measured with magnetic resonance imaging at the latest follow-up. All patients signed an informed consent form, and the protocol was approved by the institutional review board of our

Targeted hyperthermia using magnetite cationic liposomes and an alternating magnetic field in a mouse osteosarcoma model

We undertook a study of the anti-tumour effects of hyperthermia, delivered via magnetite cationic liposomes (MCLs), on local tumours and lung metastases in a mouse model of osteosarcoma. MCLs were injected into subcutaneous osteosarcomas (LM8) and subjected to an alternating magnetic field which induced a heating effect in MCLs. A control group of mice with tumours received MCLs but were not exposed to an AMF. A further group of mice with tumours were exposed to an AMF but had not been treated with MCLs. The distribution of MCLs and local and lung metastases was evaluated histologically. The weight and volume of local tumours and the number of lung metastases were determined. Expression of heat shock protein 70 was evaluated immunohistologically. Hyperthermia using MCLs effectively heated the targeted tumour to 45 degrees C. The mean weight of the local tumour was significantly suppressed in the hyperthermia group (p = 0.013). The mice subjected to hyperthermia had significantly fewer lung metastases than the control mice (p = 0.005). Heat shock protein 70 was expressed in tumours treated with hyperthermia, but was not found in those tumours not exposed to hyperthermia. The results demonstrate a significant effect of hyperthermia on local tumours and reduces their potential to metastasise to the lung.

Osteochondroma with metaphyseal abnormalities after total body irradiation followed by stem cell transplantation.

The occurrence of osteochondroma after total body irradiation (TBI) followed by stem cell transplantation (SCT) in our institutions was described, and its clinical significance discussed. Of 305 cases treated with SCT using TBI conditioning from 1980 to 2001, 4 cases of osteochondroma were identified on clinical examination. Mean age at the time of TBI was 4.4 years (range, 1.6 to 8.0). One patient developed multiple osteochondromas. All 4 cases showed metaphyseal abnormalities, including sclerotic metaphyseal lesion, fraying, and longitudinal striation, in the area where osteochondromas occurred. Only 1 patient required resection of the tumor due to pain. Two cases had other skeletal abnormalities including slipped capital femoral epiphysis and valgus-knee deformity, which required surgical intervention to prevent or correct these deformities. Osteochondroma is one of the complications developing after TBI, possibly concurrently with the metaphyseal abnormalities as seen on radiographs. However, clinical problems arising from osteochondroma are minimal, and surgical intervention is necessary in limited cases.

Transition of Treatment for Patients with Extra-Abdominal Desmoid Tumors: Nagoya University Modality

Treatment modalities for desmoid tumors have been changed because of the high recurrence rate, even after wide resection, and some cases experience spontaneous self-regression during clinical course. The treatment modality in our institutions before 2003 was surgical resection with wide surgical margin, however, meloxicam, which is a NSAID and a selective COX-2 inhibitor has been applied consecutively since 2003. We reviewed the previously reported outcomes of surgical and conservative treatment in our institutions. Among 30 patients receiving surgical treatment, 16 (53%) recurred. Younger age (p < 0.05) was a significant poor factor. According to RECIST for meloxicam treatment, CR was in one, PR in 10, SD in eight, PD in one evaluated at 2011. Older age (p < 0.01) was significantly associated with good outcome for meloxicam treatment. Results of the previous study indicated that surgical treatment alone could not control desmoid tumors, even with negative surgical margin. Considering the functional impairment resulting from surgery with negative surgical margin, a conservative and effective treatment modality with fewer complications is desired. Conservative treatment with meloxicam is a promising novel modality for patients with extra-abdominal desmoid tumors.

Regenerating the fibula with beta-tricalcium phosphate minimizes morbidity after fibula resection.

The aim of this study was to assess the radiologic and clinical outcome when beta-tricalcium phosphate is used as a bone graft substitute to backfill the fibular defect that is created by harvesting the fibula. Fourteen patients who had fibula resections to be used as bone grafts for bone tumor resections were assessed radiographically. Callus formation bridging the beta-tricalcium phosphate was seen in 12 of 14 patients at an average of 1.4 months after surgery. In these 12 patients the beta-tricalcium phosphate mostly was absorbed and replaced by newly formed bone at an average of 9.3 months after surgery. In all children, beta-tricalcium phosphate was replaced by newly formed bone at an average of 3.2 months after surgery. Only one adult patient had complete regeneration of the fibula. Few patients had continuity between the regenerated fibula and the native fibula. In one patient in whom free vascularized fibula was harvested, regeneration of the fibula was not observed. Clinical functional outcome was not correlated with successful fibula regeneration and union with the native fibula, as determined using radiographs. The results of the study suggest that, in children, regeneration of the fibula by implanting beta-tricalcium phosphate into a bone defect can reduce morbidity of the fibula harvest sites. Level of Evidence: Therapeutic study, Level IV (case series—no, or historical control group)

Treatment of Varus Ankle Osteoarthritis and Instability With a Novel Mortise-Plasty Osteotomy Procedure.

Although joint-preserving surgery for intermediate ankle osteoarthritis has been reported to be effective, failures of supramalleolar osteotomy and plafond-plasty can occur because of persistent malalignment of the distal tibia and incongruent ankle mortise. We introduce a novel opening wedge distal tibial osteotomy procedure (mortise-plasty) with rigid plate fixation combined with synthetic bone wedges. We performed 27 mortise-plasties in 25 patients with varus ankle osteoarthritis and instability. Six males (24%) and 19 females (76%), with a mean age of 63 (range 28 to 79) years, were followed up for a mean of 27.3 (range 14 to 45) months. The mean preoperative visual analog scale score, American Orthopaedic Foot and Ankle Society score, and Takakura ankle scale score were 7.4 (range 5.4 to 10), 58.7 (range 18 to 84), and 55.9 (range 29 to 88), respectively. These scores improved significantly to 2.1 (range 0 to 6.5), 89.3 (range 67 to 100), and 84.7 (range 55 to 100) postoperatively (p < .001). The mean preoperative tibial-anterior surface angle and talar tilt angle were 84.9° (range 78° to 90°) and 8.3° (range 3° to 21°), respectively. At the most recent follow-up visit, the corresponding values were 95.0° (range 82° to 99°) and 1.8° (range 0° to 8°), respectively (p < .001). Computed tomography scans indicated that the ankle mortise narrowed by approximately 1.8 mm and the tibial plafond was lowered after osteotomy. No patients underwent lateral ligament reconstruction, ankle joint replacement, or arthrodesis. Mortise-plasty osteotomy corrects the intra-articular and extra-articular deformities simultaneously and provides good clinical and radiographic outcomes for patients with varus ankle osteoarthritis and instability.

Isolated Fifth Metatarsocuboid Coalition: A Case Report

Isolated tarsometatarsal coalitions are extremely rare, and the previous 5 documented cases involved the first and third metatarsocuneiform joints. We report the case of a 69-year-old female with symptomatic fifth metatarsocuboid coalition associated with ipsilateral varus-type ankle osteoarthritis and instability. The patient was successfully treated by arthrodesis of the fifth metatarsocuboid joint, resection of the hypertrophied tuberosity of the fifth metatarsal, advancement of the peroneus brevis tendon, opening wedge distal tibial osteotomy, and calcaneal displacement osteotomy. After 1 year, 6 months, she was able to walk well, although she complained of minor discomfort under the fifth metatarsal base, which resolved with the use of protective padding. Radiographs at this stage confirmed consolidation of both the arthrodesis and the osteotomy sites. Although isolated fifth metatarsocuboid coalition is less likely to be encountered than other tarsal coalitions, it can sometimes be painful enough to necessitate surgery.

Recurrent alveolar rhabdomyosarcoma with prior surgery and radiotherapy: altered lymphatic drainage limits the reliability of sentinel lymph node biopsy.

A 7-year-old girl was diagnosed with alveolar rhabdomyosarcomas of the right crural region. The patient was initially treated with chemotherapy and surgery with wide surgical margins, with radiotherapy. The tumors relapsed in the popliteal region surrounding the popliteal vessels. The patient received sentinel lymph node biopsy for a recurrent tumor using isosulfan blue dye, with the “sentinel node” being malignant-negative, and a “nonsentinel node” positive. Sentinel lymph node biopsy with conventional blue dye alone might be insufficient to assess lymph node status in patients with recurrent rhabdomyosarcoma previously treated with surgery and/or radiotherapy.