Photodynamic therapy with acridine orange in musculoskeletal sarcomas

Limb salvage involving wide resection and reconstruction is now well established for managing musculoskeletal sarcomas. However, involvement of major nerves and vessels with a large volume of muscle and skin may result in a useless limb, contributing to depression and a low quality of life. We have been studying alternative treatments for musculoskeletal sarcoma since 1990, and have recently established a regime using photodynamic surgery with cells labelled with acridine orange, photodynamic therapy with cells treated similarly and radiodynamic treatment using the effect of X-rays on such cells. These techniques have been used after marginal or intralesional resection of tumours since 1999 and have enabled maintenance of excellent limb function in patients with sarcomas.

Histiocytic osteolysis secondary to hyperbilirubinaemia: a case report

A 6-year-old boy with Alagille syndrome, characterised by marked hyperbilirubinaemia, presented with malunion of a pathological fracture of the femur with local bone atrophy and insufficient callus formation. During corrective osteotomy, it was noted that the femur was stained dark green, suggestive of bilirubin deposition. Histology of the resected bone revealed the presence of many histiocytes and osteoclast-like multinucleate giant cells containing bilirubin particles in the cytoplasm causing bone resorption. These findings suggest that bilirubin may activate macrophages to form osteoclast-like multinucleate giant cells, resulting in histiocytic osteolysis.

Safety of external fixation during postoperative chemotherapy

We studied the safety of external fixation during post-operative chemotherapy in 28 patients who had undergone distraction osteogenesis (17, group A) or vascularised fibular grafting (11, group B) after resection of a tumour. Four cycles of multi-agent post-operative chemotherapy were administered over a mean period of 14 weeks (6 to 27). The mean duration of external fixation for all patients was 350 days (91 to 828). In total 204 wires and 240 half pins were used.

During the period of post-operative chemotherapy, 14 patients (11 in group A, 3 in group B) developed wire- and pin-track infection. A total of ten wires (4.9%) and 11 half pins (4.6%) became infected. Seven of the ten infected wires were in periarticular locations.

External fixation during post-operative chemotherapy was used safely and successfully for fixation of a vascularised fibular graft and distraction osteogenesis in 27 of 28 patients. Post-operative chemotherapy for malignant bone tumours did not adversely affect the ability to achieve union or cause hypertrophy of the vascularised fibular graft and had a minimal effect on distraction osteogenesis. Only one patient developed osteomyelitis which required further surgery.

Asymptomatic disseminated carcinomatosis of bone marrow presenting as hyperphosphatasia: report of a case

Metastatic involvement of the musculoskeletal system is one of the most significant clinical issues facing orthopaedic oncologists. The number of patients with metastasis to the skeletal system from a carcinoma is 15 times greater than the number of patients with primary bone tumours of all types. However, progression patterns like disseminated carcinomatosis of bone marrow are comparatively rare. The pathophysiology for disseminated carcinomatosis of bone marrow, with a prognosis reported to be very poor, is still unknown. We describe a patient who had no symptoms with hyperphosphatasia. Bone scintigraphy showed a so-called super bone scan and a needle biopsy from the ileum showed adenocarcinoma cells. Additional endoscopic investigation was performed and signet cell gastric cancer was found. From the bone scan and biopsy, we established the diagnosis of disseminated carcinomatosis of the bone marrow. From the experience of this case, we believe that intensive stomach investigation should be considered in cases with hyperphosphatasia, even when the patient has no symptoms.

Foreign-body granulomas in the trunk and extremities may simulate malignant soft-tissue tumors: report of three cases

Three cases of foreign-body granulomas arising from soft tissues of the extremities or trunk are reported. All patients had a history of having undergone surgery 19 to 35 years ago. It was difficult to distinguish these granulomas from malignant soft-tissue tumors preoperatively by magnetic resonance (MR) images, as the tumors were over 10 cm in diameter and degenerated foreign bodies could not be detected on MR images. Finally, a histological diagnosis of foreign-body granuloma was made by preoperative or intraoperative biopsy in all cases. A palpable tumor adjacent to a previous surgery scar is therefore a warning that it might represent a granuloma, in spite of various image findings.

Intra-osseous ganglion of the proximal humerus: a case report

We report a 72-year-old woman with a type-1 intra-osseous ganglion in the proximal humerus, extending to the bone surface. We conducted a systemic review of intra-osseous ganglion cases in Japan to identify clinical features and pathogenesis of this condition. The anatomical distribution between intra-osseous ganglia without a communicating soft tissue ganglion (type 1) and those with (type 2) is different. The origins of intra-osseous ganglia vary and depend on their anatomical location. They can arise from within the bone or in the adjacent soft tissue, and can progress to a type-2 lesion in either an outside-in or inside-out fashion.

Soft-tissue sarcoma mimicking large haematoma: a report of two cases and review of the literature

We report on 2 patients with soft-tissue sarcomas mimicking large haematomas. Neither patient had a medical history of trauma or bleeding tendency. In a patient with a large leiomyosarcoma in the buttock, insufficient biopsy material from initial surgeries precluded a correct diagnosis. In the second patient with epithelioid sarcoma of the forearm, fasciotomy was repeatedly performed for compartment syndrome arising from the tumour. It is important to reconfirm prior trauma and investigate the clinical course and images of patients with an unusual history of haematoma in the extremities. The possibility of a malignant tumour should be suspected, and repeated biopsies should be performed if necessary.

Intraneural metastasis of a synovial sarcoma to a peripheral nerve

We describe a case of intraneural metastasis of a synovial sarcoma, the first published case of a metastasis of a soft-tissue sarcoma to a peripheral nerve.

Intraneural metastasis of a synovial sarcoma to a peripheral nerve

We describe a case of intraneural metastasis of a synovial sarcoma, the first published case of a metastasis of a soft-tissue sarcoma to a peripheral nerve.

Calcium hydroxyapatite ceramic implants in bone tumour surgery. A long-term follow-up study

We reviewed the results of 51 patients with benign bone tumours treated by curettage and implantation of calcium hydroxyapatite ceramic (CHA). The mean follow-up was 11.4 years (10 to 15.5). Post-operative fractures occurred in two patients and three had local recurrences; three had slightly limited movement of the adjacent joint and one had mild osteoarthritis. There were no allergic or neoplastic complications. In all cases, radiographs showed that the CHA was well incorporated into the host bone. Statistical analysis showed that absorption of the implanted CHA was greater in males (odds ratio, 6.2; 95% CI, 1.6 to 23.7) and younger patients (odds ratio, 0.6 for increase in age of 10 years; 95% CI, 0.91 to 0.99). However, the implanted CHA was not completely absorbed in any patient. We conclude that CHA is a useful and safe bone substitute for the treatment of benign bone tumours.

Eleven cases of intraosseous lipoma of the calcaneus

Intraosseous lipomas are rare benign primary bone tumors, with an incidence of one per thousand bone tumors. We studied eleven cases of intraosseous lipoma of the calcaneus. All the patients received radiographic examinations and MRI with T1-and T2-weighted images with Gd-DTPA enhancement. Seven patients received tumor curettage. Plain radiographs demonstrated that all of the lesions showed clear osteolysis surrounded by a sclerotic margin in the central body of the calcaneus. MRI revealed that all the lesions had demarcated homogenous high signal intensity lesions on both T1- and T2-weighted images, which strongly suggested adipose tissue. In 5 cases, the center of the lesion showed low signal intensity lesions on T1-weighted images, suggesting the existence of central necrosis or cyst formation. After excising the tumors of 7 patients, there was no local tumor recurrence. Surgical intervention was considered unnecessary in all cases after the diagnosis of an intraosseous lipoma was determined by MRI.

Multiple bone lesions after allogeneic bone marrow transplantation in a patient with relapsed adult acute lymphoblastic leukemia: minimal residual disease analysis may predict extramedullary relapse

We describe a patient with acute lymphoblastic leukemia (ALL, L2) who relapsed with multiple bone lesions after allogeneic bone marrow transplantation (allo-BMT). Allo-BMT was performed from an HLA-identical sibling during the first hematological complete remission (CR). Minimal residual disease (MRD) assessed by polymerase chain reaction (PCR) with primers for T cell receptor delta (TCRdelta) gene became positive in the bone marrow sample on day 46 after allo-BMT. On day 113, the patient complained of a painful tumor at the right clavicle. The examination of biopsy specimen revealed infiltration of leukemic cells. After partial response was achieved by local radiotherapy, disseminated bone lesions were demonstrated by 99mTC scintigraphy scan, followed by bone marrow relapse on day 137. The patient died of cardiac tamponade on day 236 after Allo-BMT. MRD assessed by PCR assay for TCRdelta gene in the bone marrow is useful for the prediction of extramedullary as well as medullary relapse after BMT.

DNA cytofluorometric analysis of chondrocytes in human articular cartilages under normal aging or arthritic conditions

OBJECTIVE

Since most chondrocytes in articular cartilage are in the resting phase (G0) of the cell cycle, it has been difficult to investigate their cell kinetics using 3H-thymidine autoradiography, or immunohistochemistry. In the present study, DNA cytofluorometry, which is useful to analyse the cell kinetics even for such inactive cell populations as in the G0 phase, was applied to human chondrocytes of the articular cartilages under normal aging and pathologic conditions such as osteoarthritis (OA), rheumatoid arthritis (RA), and aseptic necrosis (AN).

DESIGN

The human articular cartilages for the study were obtained from autopsy and surgical materials. Fifty joints were used for the study of aging, 54 for the study of OA, 20 for studying RA, and 10 for AN study. The isolated chondrocytes were quickly prepared from fresh articular cartilages, using a combination method of enzymatic digestion with papain and collagenase, followed by mechanical cell separation by churning and homogenization.

RESULTS

The DNA histograms obtained by cytofluorometry with propidium-iodide staining showed that most chondrocytes had diploid DNA content (2c) in all cartilages studied, suggesting that they were in the G0 phase. However, there were a few chondrocytes having tetraploid DNA content (4c) in the normally aged articular cartilages, and there were some cells having DNA content between 2c and 4c in the diseased cartilages. The former cells were considered to be G0-phase cells of the 4c chondrocytes, while the latter cells were considered to be in the DNA synthetic (S) phase or G2-phase of the 2c chondrocytes. The frequency of 4c chondrocytes in aged cartilage was significantly increased, compared to that in the young cartilage. In contrast to the normal cartilage, the frequency of S- and G2-phase cells, which was expressed as the S- G2 index, in diseased cartilages (OA, RA and AN) was significantly high (P< 0.0001). In OA cartilage, the S-G2 index was much higher in the severe or moderate stage than in the mild stage, suggesting that the chondrocytes in clusters may actively proliferate.

CONCLUSION

These results showed that in normal articular cartilages most chondrocytes are in the G0 phase, while some became 4c polyploid cells, and that these G0-phase chondrocytes had a potential to proliferate under diseased conditions.

Bone reaction induced by femoral stem of titanium alloy endoprosthesis for malignant bone tumors at the distal femur

We demonstrated radiological evaluations after limb salvage surgery with an uncemented titanium endoprosthesis possessing a rotating hinge-type knee joint for 7 patients with malignant bone tumors at the distal femur. Although radiographically, cortical hypertrophy and new bone formation at the junction between implant and cortex appeared in all cases, there was a small quantity of subsidence of the implant in all cases. Loosening of the stem was found in 2 patients at 4 and 9 years after surgery. However, after revision surgery, the function restored as before. The latest average functional score according to the system of the International Society of Limb Salvage was good, being 73%.

Ceramic endoprosthesis for aggressive giant cell tumors near the knee: eight cases followed for more than 10 years

Eight patients with locally aggressive giant cell tumor were treated with marginal resection and implantation of a ceramic endoprosthesis with a non-hinged knee joint. The patients have been followed-up for between 10 to 16 years. Newly formed bone appeared at the junction between implant and cortex and in 2 cases subsidence of the implant was seen. All the patients had good function of the knee and no revision was needed.

Extra-articular wide tumor resection and limb reconstruction in malignant bone tumors invading the knee joint

We demonstrate our procedure of extra-articular wide tumor resection and its clinical outcome. The knee joint including the femorotibial, patellofemoral and the proximal tibiofibular joints was totally resected without any view of articular cartilage and synovium. The resected limb was reconstructed with endoprosthesis of the knee joint. The average score of the limb function evaluated by ISOLS criteria was 69.3% in all patients. The limb function of these patients was almost the same as that of the patients who received the intra-articular procedure. The procedure of extra-articular resection was theoretically necessary and clinically practical.

Effectiveness of activated vitamin D3 on improving prognosis of osteosarcoma patients

We examined the survival prognosis of patients with osteosarcoma after orally administering the active form of vitamin D3, 1alpha (OH) D3 (alphaD3). The 29 patients, ranging in age from 9 to 58 years (mean, 19 years), with osteosarcoma were treated in our department between 1983 and 1995. The surgical stage was IIB in all patients. Among the 29 patients, alphaD3 was administered to 18 patients, and the remaining 11 patients served as controls. These patients underwent chemotherapy mainly with adriamycin and cisplatin, and wide tumor resection. In the alphaD3-treated group, the 5- or 10-year survival rate was 61.1%, while in the untreated group, the 5-year survival rate was 63.6%, and 10-year survival rate was 33.9%. Prognosis of the patients treated with alphaD3 tended to be better than that of untreated patients, but there was no significant difference in the survival rate between the groups (p=0.3823). The survival rate in the group treated with a total dose of alphaD3 more than 1,500 microg was also higher than that in the untreated group, but the difference was not significant (p=0.0740). Therefore, we concluded that alphaD3 at the dose used in this study was not effective in improving the prognosis of osteosarcoma patients.

Relationship between histologic grade and cytofluorometric cellular DNA and RNA content in primary bone tumors

The diagnosis and grading of bone tumors remains a challenging problem. We studied the relationship between histologic grade and cytofluorometric cellular DNA and RNA content in 108 primary bone tumors. The data included DNA ploidy, mean DNA content (MDC), S-phase fraction (SPF), mean RNA content (MRC) and RNA/DNA ratio (RDR; MRC/MDC) which represents the RNA content normalized for the DNA content. Benign tumors had a diploid stem line with low MDC (mean; 1.04), low SPF (0.9), high MRC (2.41) and high RDR (2.31). Giant cell tumors of bone, which are locally aggressive benign tumors, showed diploidy with relatively higher MDC (1.07, p < 0.01) and SPF (2.6, p < 0.01) and lower MRC (1.81, p < 0.01) and RDR (1.69, p < 0.01). Similar results were obtained in low-grade sarcomas. In high-grade sarcomas, the data depended on the histologic findings. Pleomorphic sarcomas such as osteosarcomas revealed aneuploidy with remarkably higher MDC (1.70 in osteosarcomas, p < 0.01) and SPF (6.5, p < 0.01), but lower RDR (1.70, p < 0.01). In contrast, small cell sarcomas, such as Ewing's sarcomas, showed diploidy with low MDC (1.11 in Ewing's sarcomas, N.S.) and SPF (2.5, p < 0.01) and extremely low RDR (1.34, p < 0.01). The RDR value was higher in well-differentiated tumors than in primitive tumors, rendering it useful in grading bone tumors with a diploid stem line. By combining the RDR value with the MDC value, 96% of diploid sarcomas could be distinguished from benign tumors. These results indicate that cellular DNA and RNA content analysis may be of value in assessing the malignant potential of diploid as well as aneuploid bone sarcomas.

Acridine orange induces binucleation in chondrocytes

OBJECTIVE

Although it is well known that binuclear cells commonly appear among the chondrocytes of normal cartilages as well as among neoplastic chondrocytes of chondrosarcomas, the mechanism of binucleation is still unclear. Therefore, this study was undertaken to clarify the mechanism of binucleation in chondrocytes, using primary culture cells of growth plate cartilage.

DESIGN

These chondrocytes were exposed to acridine orange (AO) which is a fluorescent dye for differentiating certain DNAs and RNAs in nuclei and cytoplasm, and which inhibits mitosis. After exposure to 0.5 microg/ml AO, for 0, 6, 24, 48, and 96 h, the following parameters were investigated: (1) cell growth rate (GR); (2) frequency of hyperdiploid cells (%HDC) by DNA cytofluorometry; (3) mitotic index (MI); (4) BrdU labeling index (LI); (5) frequency of binuclear cells (%BNC).

RESULTS

Compared with the control cells, which were cultured in AO-free medium, the GR was remarkably inhibited at 24 h. MI was also decreased from 6 to 24 h, and LI decreased at 48 h. However, these parameters were recovered at 96 h. The %HDC was increased from 6 to 96 h, and the %BNC was also increased to a maximum of six times that of the control cells at 96 h.

DISCUSSION

These results suggested that the binuclear cells observed among the cultured chondrocytes may be formed from G2 arrested cells by amitotic nuclear division, but not by mitosis without cytoplasmic division or cell fusion.

Oral administration of 1 alpha hydroxyvitamin D3 inhibits tumor growth and metastasis of a murine osteosarcoma model

We studied the effect of oral administration of 1 alpha hydroxyvitamin D3 (1-D3) on the growth and metastatic ability of Dunn murine osteosarcoma model. A solution of 1-D3 or vehicle alone was administered daily for 2 weeks to tumor-bearing mice using an esophageal tube and tumor size was serially monitored. In 1-D3-treated mice, the growth of Dunn osteosarcoma was significantly suppressed in a dose-dependent manner. Histologically, tumor cells in the control mice proliferated in marginal regions of the tumor with wide central necrosis, whereas in the 1-D3-treated mice, tumor cells were distributed as scattered islands among extensive necrotic tissue. The mean tumor necrosis area was 55.7% in the control tumors and 94.6% in 1-D3-treated tumors (p < 0.001). There were no substantial differences in the cytofluorometric cell cycle distribution or the histological mitotic index between control and 1-D3-treated tumors. When 1-D3 was administered to mice from 2 days before to 2 weeks after transplantation of the tumor, there were significantly fewer metastatic foci in the lungs in 1-D3-treated mice than in control mice. We also tested the effect of coadministration of 1-D3 and doxorubicin on the growth of Dunn osteosarcoma and found that these two drugs act additively to suppress tumor growth. These results indicated that 1-D3 given orally inhibits tumor growth and metastases in a Dunn osteosarcoma model. Although the mechanism remains unknown, oral administration of 1-D3 might be promising as a new method of treating human osteosarcoma.

Extraskeletal osteosarcoma arising in myositis ossificans

A 53-year-old woman had extraskeletal osteosarcoma that developed from a soft tissue bony mass present on the volar aspect of the left wrist for 4 years. Initially, the bony mass was soft and movable, but during the first year it became hard and fixed. The patient had no history of trauma. Because the lesion did not grow or cause any symptoms, the patient did not come to the hospital until 4 years after she first noticed the lesion. Radiologically, the bony mass had features characteristic of mature myositis ossificans, showing "eggshell" ossification. A nonmineralized soft tissue mass occurred between the surface of the radius and the bony shell. Histologically, a high-grade osteosarcoma was present between the surface of the radius and the well-differentiated bone tissue, which included fatty and hematopoietic marrow. All the findings indicated that our patient had an extremely rare case of malignant transformation of myositis ossificans.

Drug resistance modification using pulsing electromagnetic field stimulation for multidrug resistant mouse osteosarcoma cell line

Multidrug resistance (MDR) is one of the major problems in osteosarcoma chemotherapy. Therefore, methods of overcoming MDR are urgently needed. In this study, we investigated the effects of pulsing electromagnetic field stimulation (PEMFs) on a MDR murine osteosarcoma cell line which strongly expresses P-glycoprotein (P-gp). To assess the reversal effects of PEMFs on doxorubicin (DOX) resistance, MTT assay was applied. Viable cells were assessed by the trypan blue exclusion test. Fluorescence intensity of DOX binding to nuclear DNA of each cell was measured using a cytofluorometer. Changes in P-gp expression in each cell were detected by the indirect immunofluorescence method using an antibody to Pgp. PEMFs increased DOX binding ability to nuclear DNA and inhibited cell growth, although it had no significant effect on P-gp expression. These findings indicated that PEMFs reversed the DOX resistance of the MOS/ADR1 cells by inhibiting P-gp function. The results suggested that PEMFs may be useful as a local treatment for MDR osteosarcoma.

Development of bone canaliculi during bone repair

We recently found that silver impregnation staining with protargol (silver protein), that is, a modified Bodian method, is useful for histologically identifying the details of bone canaliculi structure, using thin sections of decalcified bone tissues. With this staining method, we conducted the present study to assess the development of bone canaliculi during the process of intramembranous ossification using a fracture-like stimulation model of the rat femur. After making a drill-hole in the cortex of the rat femur, decalcified thin sections were obtained after 3, 5, 7, and 14 days by the standard paraffin-embedding procedure. Silver staining for bone canaliculi was performed using our previously reported technique. The results showed that woven bone covered the fracture surface of the cortex after 5 days, then immature lamellar bone attached to the woven bone after 7 days, and finally the lamellar bone matured and became thick with appositional growth after 14 days. The osteocytes in the woven bone appeared at an early stage of bone repair and developed a few canaliculi that were short and irregularly distributed in the osteoid matrix, while the osteocytes in the lamellar bone at a late stage formed many bone canaliculi that were long and regularly distributed in mature bone matrix. Therefore, we concluded that woven bone osteocytes may be necessary for induction of the lamellar bone osteocytes followed by active appositional growth of the lamellar bone at the early stage of bone repair, and also that both bone tissues could be clearly distinguished from one another based on the pattern of development of bone canaliculi by the osteocytes, as seen with the use of our sensitive staining method.

DNA cytofluorometric analysis of benign and malignant nerve sheath tumors

The present study was undertaken to examine the ploidy patterns of benign and malignant nerve sheath tumors using PI-DNA cytofluorometry and to clarify the relationship between the ploidy patterns and pathological findings for these lesions. The benign nerve sheath tumors (schwannomas and neurofibromas) were found to be dipolid or to be euploid-polyploidization, with a few DNA synthetic cells. The number of polyploid cells increased with increase in the frequency of cells with large and atypical nuclei in histology, regardless of the natures of cellular arrangements. Malignant schwannomas were composed of many polyploid and aneuploid cells with DNA synthetic cells, indicating their active cell proliferation. Thus, benign nerve sheath tumors exhibited low-proliferative ploidy patterns that were clearly different from those of malignant nerve sheath tumors. As Takeshita has already stated, it is difficult to ascertain why some of the neurogenic tumors show euploid-polyploidization (19). Further investigations will be needed in this direction. Finally, it is clear from the results of this study that the cytofluorometric analysis mentioned above is useful for assessing malignancy and that it may be useful for predicting prognosis of nerve sheath tumors.

Binuclear cells induced by acridine orange in giant cell tumor of bone

We have recently found the presence of many binuclear cells among isolated and smeared cells in giant cell tumor of the bone (GCT). These binuclear cells are possibly associated with the formation of multinuclear cells. Therefore, this study was undertaken to clarify the mechanism of binucleation in GCT, using primary culture cells exposed to acridine orange (AO) which is a fluorescent vital staining dye for the cytoplasm and nucleus and which inhibits mitosis. The cells were isolated from explants of fresh tumor materials obtained from two GCT patients (GCT1 and GCT2). These cells were cultured in Dulbecco's modified Eagle medium (DMEM) with 10% Fetal calf serum (FCS). After exposure to 0.5 microgram/ml AO, for 0, 6, 24, 48, 96 and 144 hours the following parameters were investigated: 1) cell growth rate (GR); 2) frequency of hyperdiploid cells (%HDC) by DNA cytofluorometry; 3) mitotic index (MI); 4) BrdU labeling index (LI); 5) frequency of binuclear cells (%BNC). Compared to the control cells which were cultured in AO-free medium, the GR of both GCT cells exposed to AO was remarkably inhibited. The MI was 0 from 24 to 144 hours. The %HDC was increased at 24 hours and was maintained high until 144 hours. The LI was temporarily increased at 6 hours, but was decreased at 48 hours. The %BNC was gradually increased. AO inhibited DNA synthesis and cell mitotic activity in cultured GCT cells and it finally caused inhibition of cell growth. However, the frequencies of G2 arrest cells and binuclear cells were increased. These results suggested that the binuclear cells in GCT may be formed from G2 arrest cells by amitotic nuclear division, but not by mitosis without cytoplasmic division, or by cell fusion.

Assessment of chemosensitivity in patients with malignant bone and soft tissue tumors using thallium-201 scintigraphy and doxorubicin binding assay

This study was performed to compare the accumulation of thallium (Tl)-201 which is correlated with malignancy and the doxorubicin binding ability, which is correlated with chemosensitivity, in nine patients who received preoperative chemotherapy with doxorubicin and cisplatin. Tl-201 scintigraphy was performed at 15 minutes (early image) and 3 hours (delayed image) after injection of 111 MBq of Tl-201. The change of degree of the radionuclide uptake between the early and delayed images was evaluated before and after preoperative chemotherapy. The doxorubicin binding ability (%DB) to nuclear DNA in living tumor cells isolated from biopsy materials was assessed by doxorubicin binding assay. The histologic response to preoperative chemotherapy was evaluated by the percentage of tumor necrosis. Before preoperative chemotherapy no changes of Tl-201 uptake between the early and delayed images was detected in any tumors. Five patients, who had no change of Tl-201 uptake after preoperative chemotherapy, showed a poor histologic response and had a %DB ranging from 10% to 70% (mean: 36.0%). The other four patients, who had a %DB greater than 90%, showed a good histologic response. All of these four patients had decreased Tl-201 uptake after preoperative chemotherapy. This study demonstrated that doxorubicin binding assay and midcourse Tl-201 scintigraphy are useful methods to assess the response to chemotherapy early in malignant bone and soft tissue tumors.

Case report of secondary chondrosarcoma showing spontaneous regression after frequent recurrences

We report a case of secondary chondrosarcoma arising in the ilium showing spontaneous regression after frequent local tumor recurrences followed by multiple surgeries of marginal or intralesional excision. The patient was a 16-year-old boy who had been diagnosed as having multiple exostosis from 9 years of age. He experienced an increasing abdominal tumor mass that formed a huge tumor. Although marginal resection of the tumor was attempted, intraperitoneal dissemination was caused by rupture of the tumor capsule and the peritoneum, as a result of severe tumor adhesion to the peritoneum. During the 5 years after the initial operation, local recurrences occurred seven times in various areas of the intra- or retro-peritoneum and marginal or intralesional excision was performed every time for a total of 14 tumors. However, since the seventh operation, the patient has had no evidence of recurrence or metastasis of the disease for more than 10 years. Therefore, we considered that the cancer might have spontaneously regressed.

Nerve contact with muscle component in neuromuscular hamartoma

Neuromuscular hamartoma is a very rare soft tissue tumor, of which only 20 cases have been reported previously. None of these reports has described the relation between hamartomatous skeletal muscle and nerve fibers in the tumor. We experienced a patient with neuromuscular hamartoma arising at the brachial plexus. In this tumor, the localization of synaptophysin (SYP), S-100 protein (SP), neuron-specific enolase (NSE) neurofilament protein (NFP) and myoglobin (MG) was immunohistochemically detected. The results showed that SYP and MG were diffusely localized in the hamartomatous muscle fibers, SP in the schwann cells, and NSE and NFP in the axons of the hamartomatous nerve. Therefore, it is suggested that in the neuromuscular hamartoma, the structure of the neuromuscular junction may be similar to that in the motor end-plate of the normal muscle, but it may not be functional, because the hamartomatous muscles could not contract by nerve stimulation.

Fluorovisualization effect of acridine orange on mouse osteosarcoma

If the localization of musculoskeletal sarcomas could be visualized during surgery, it would be possible to completely resect the tumor with minimum damage to normal tissues and the patients could retain a functional limb. Therefore, we conducted the present study to clarify the usefulness of acridine orange (AO) for fluorovisualization of tumors using a mouse osteosarcoma model. At 2 hours after injection of 10 mg/kg AO to mice inoculated with MOS mouse osteosarcoma cells, fluorovisualization of mouse osteosarcoma reached the maximum level. Even a 1-mm-diameter lesion of pulmonary metastasis was visualized. The results suggested that AO may be useful for specific fluorovisualization of human osteosarcomas during surgery.

Extraabdominal desmoid tumor with dissemination detected by thallium-201 scintigraphy

Extraabdominal desmoid tumor is a locally aggressive tumor despite being histologically benign. To avoid local recurrence, it is important to preoperatively detect the exact localization and extension of the infiltrating or disseminating lesion in this tumor. We report a case of recurrent extraabdominal desmoid tumor, which arose in the posterior thigh region, detected with Tl-201 (Tl) scintigraphy. In this case, Tl accumulated in the small disseminating lesion and to the recurrent tumor. This lesion was not identified by palpation because of its small size, deep localization and absence of symptoms, although MR imaging, which was performed after the Tl scintigraphy, clearly showed the lesion. After tumor resection, Tl did not accumulate in any region. These results suggest that Tl scintigraphy may be useful, not only for the diagnosis of extraabdominal desmoid tumor, but also for the detection of the exact localization or extension of small infiltrating or disseminating lesions before treatment.

Relationship between doxorubicin binding ability and tumor volume decrease after chemotherapy in adult malignant soft tissue tumors in the extremities

We have previously reported that the doxorubicin (DOX) binding ability detected by the DOX (or adriamycin) binding assay closely correlated with the chemosensitivity of human osteosarcomas (1). We performed the present study to clarify the relationship between the DOX binding ability (%DB) and the histologic response, rate of decrease in tumor volume of malignant soft tissue tumors after preoperative chemotherapy and prognosis. Nine malignant soft tissue tumors (4 liposarcomas, 3 synovial sarcomas, one malignant fibrous histiocytoma (MFH) and one extraskeletal osteosarcoma (EOS)) which arose at the extremities of adult patients were analyzed by the DOX binding assay using freshly biopsied specimens. After preoperative chemotherapy including DOX or pirarubicin (THP), the rate of decrease in tumor volume was measured using magnetic resonance imaging, and the histologic response expressed as tumor necrosis to chemotherapy was also investigated. All the patients, apart for one, were continuously disease-free after treatment. One patient with EOS died of metastatic disease before surgery. The histologic response in 8 tumors without EOS was poor. The %DB of 5 tumors was greater than 80% (average: 95.90%), whereas that of 4 tumors was less than 80% (average: 38.33%). Although there was no correlation between the %DB and the histologic response, or prognosis, a significantly positive correlation was found between the %DB and the rate of decrease in tumor volume (r = 0.7455, p < 0.05). These results suggest that in malignant soft tissue tumors, the rate of decrease in tumor volume after chemotherapy might be a better indicator for chemosensitivity than the histologic response and also that the DOX binding ability might be a good predictor for chemosensitivity before chemotherapy.

Total tumor cell elimination with minimum damage to normal tissues in musculoskeletal sarcomas following photodynamic therapy with acridine orange

Acridine orange (AO) has unique biological actions enabling tumor visualization (fluorovisualization) and a strong cytocidal effect (photodynamic therapy: AO-PDT) under illumination with blue light. Accordingly, in this study, we attempted to develop a new surgical technique for total tumor cell elimination using these photodynamic reactions with AO in a mouse osteosarcoma model. The results showed that local tumor recurrence was significantly inhibited (23%) in the group treated with curettage under fluorovisualization and AO-PDT, compared to that (80%) in the control group treated with curettage alone under ordinary light. Therefore, we concluded that the combination of curettage under fluorovisualization and AO-PDT may be useful for total tumor cell elimination with minimum damage to normal tissue in musculoskeletal sarcomas.

Intrinsic resistance to chemotherapeutic agents in murine osteosarcoma cells

BACKGROUND

There are two general categories of drug resistance: acquired and intrinsic. The mechanisms involved in acquired drug resistance have been extensively studied, and several mechanisms have been described. However, the mechanisms responsible for intrinsic drug resistance have not been elucidated, to our knowledge. The purpose of the present study was to investigate the cytological and biochemical differences between acquired and intrinsic drug resistance in osteosarcoma cells.

METHODS

We previously isolated a clonal cell line (MOS/ADR1) to study acquired resistance in osteosarcoma by exposure of parental murine osteosarcoma cells (MOS) to doxorubicin. In the present study, we cloned a new, intrinsically resistant cell line (MOS/IR1) by single-cell culture of MOS cells and we investigated the differences in cell phenotype and the mechanisms of resistance in both of these resistant clones.

RESULTS

The MOS/ADR1 and MOS/IR1 cells were sevenfold and fivefold more resistant to doxorubicin than the parental murine osteosarcoma cells. Morphologically, the MOS/ADR1 cell line was composed of polygonal cells, whereas the MOS/IR1 cell line consisted of plump spindle cells with long cytoplasmic processes. The MOS/IR1 cells showed a much lower level of alkaline phosphatase activity than did the MOS/ ADR1 and MOS cells. There were no substantial differences in the cellular DNA content or the doubling time among these three lines. Overexpression of the P-glycoprotein involved in the function of an energy-dependent drug-efflux pump was detected in the MOS/ADR1 cells but not in the MOS/ IR1 cells. After the cells were incubated with doxorubicin for one hour, the two resistant lines had less accumulation of the drug than did the parent line (p < 0.05). The addition of a P-glycoprotein antagonist, verapamil, or the depletion of cellular adenosine triphosphate resulted in a marked increase in the accumulation of doxorubicin in the MOS/ADR1 cells (p < 0.05) but not in the MOS/ IR1 cells. The MOS/ADR1 cells were found to exhibit cross-resistance only to substrates for P-glycoprotein (such as doxorubicin, vincristine, and etoposide), whereas the MOS/IR1 cells were resistant to all of the drugs studied (including cisplatin and methotrexate). The degree of drug resistance in the MOS/IR1 cells was found to be associated with the molecular weight of the drugs (p < 0.05). Permeabilization of the plasma membrane by saponin increased both the accumulation of doxorubicin (p < 0.05) and the cytotoxic activity of this drug in all lines, but the effects were most pronounced in the MOS/IR1 cells.

CONCLUSIONS

Taken together, this data suggests that reduced drug accumulation in the MOS/IR1 cells may be due to the effect of decreased permeability of the plasma membrane on the transport of drugs from the extracellular environment into the cytosol of the cell and that this may be the mechanism responsible for intrinsic resistance to multiple drugs in the MOS/IR1 cell line.

CLINICAL RELEVANCE

Current drug treatment for human osteosarcoma may include multiple chemotherapeutic agents, such as doxorubicin, cisplatin, and methotrexate. These drugs exhibit different cytotoxic actions and, thus, the mechanisms of resistance to individual drugs vary. Clinical resistance to multidrug chemotherapy may be observed in tumors that recur after repetitive chemotherapy and in previously untreated tumors. In the former group, a tumor cell may express multidrug resistance by combining several different mechanisms due to its exposure to various drugs. In the latter group, however, this is not likely. Decreased intracellular drug accumulation due to reduced permeability of the plasma membrane, found in the MOS/IR1 cells, is one possible mechanism and may explain the intrinsic resistance to multidrug chemotherapy for the treatment of osteosarcoma. Further study regarding the resistance mechanism in the MOS/IR1 cells may help to overcome the intrinsic drug resistance in oste

More than 10 years of follow-up of two patients after total femur replacement for malignant bone tumor

One patient with osteosarcoma and one with Ewing's sarcoma of the femur were in 1987 and 1988 treated with prosthetic replacement of the femur and chemotherapy. There has been no loosening of the prostheses and no recurrence of the tumor. The patients have maintained 60% and 63% limb function scores evaluated by ISOLS criteria.

Relationship between binuclear and multinuclear cells in giant cell tumor of bone

Giant cell tumor of bone (GCT) consists of stromal and multinuclear type tumor cells. Although most people believe that the stromal cells are mononuclear, we recently found the existence of many binuclear cells among stromal cells using DNA cytofluorometric examination. This study, using 18 tumors of GCT was conducted to elucidate the cell biological significance of the binuclear cell, especially its relationship to multinuclear cell formation or tumor cell proliferation. The investigation was carried out by means of DNA-RNA cytofluorometry with acridine orange (AO) and histological method. Using fluorescence microscopic observation, we counted the numbers of both mononuclear and binuclear cells and calculated the index of % BNC, which expresses the frequency (percentage) of binuclear cells in a population of mononuclear and binuclear cells. The index of % S-G2 obtained by DNA-RNA cytofluorometry showed the frequency (percentage) of mononuclear cells in the S and G2 phases of the cell cycle. In the histological study, we counted the numbers of multinuclear giant cells with more than 3 nuclei in the cytoplasm and stromal cells including mononuclear and binuclear cells and calculated MNS/SC, which showed the percentage of multinuclear cells in the stromal cells in the microscopic field. Eight tumors showed a value of % BNC greater than 10% and 2 had a value of 40%. The index of % BNC significantly correlated with the average value of MNC/SC in all tumors. There was no significant correlation between % BNC and the average value of % S-G2, in 18 tumors although 4 tumors having a % BNC value greater than 20% showed a % S-G2 value greater than 12% in 18 tumors. These results revealed the presence of many binuclear cells among stromal cells of GCT and suggested that these binuclear cells might be formed in association with the active proliferation of mononuclear cells and closely relate to the formation of multinuclear giant cells.

Bilateral metachronous periosteal tibial amyloid tumors

Localized primary periosteal amyloid tumors are extremely rare. A case of bilateral tibial amyloid tumor is presented. A 62-year-old woman initially presented with a painful mass in the anterior aspect of the right leg. There was no evidence of underlying systemic disease, including chronic infection or malignancy. Based on the results of resistance with Congo red staining to treatment with potassium permanganate and positivity for kappa light chain, we classified this particular case as AL-type amyloidosis. The patient noticed a swelling in the opposite leg 2 years later. The second tumor was also an AL-type amyloidoma. Amyloid tumors are generally solitary. This is the first case of bilateral periosteal amyloid tumors of the AL-type occurring in the tibiae.

Angiomyolipoma arising in the thigh

A 41-year-old man presented with an asymptomatic mass in the right medial thigh. Magnetic resonance imaging (MRI) revealed a well-demarcated, 10-cm mass in the right adductor muscles. The margins of the mass exhibited high signal intensity and the rest showed low or iso signal intensity on T1-weighted MR images. However, the high signal intensity was decreased on T2-weighted images with fat suppression. The central part of the tumor was of inhomogeneous high signal intensity on T2-weighted images; after Gd-DTPA injection it enhanced in homogeneously on T1-weighted images with fat suppression. On dynamic computed tomography (CT) in the arterial phase, there were strongly enhancing spotty areas in the tumor. At surgery, a yellow-whitish tumor was resected and a pathological diagnosis of angiomyolipoma (AML) in the thigh was made.

Osteoblastic differentiation and P-glycoprotein multidrug resistance in a murine osteosarcoma model

A recent study of multidrug resistance (MDR) 1 gene transfected osteosarcoma cells found a cause-effect relationship between increased expression of P-glycoprotein (P-gp) and a low aggressive phenotype. However, several experimental and clinical studies have observed contradictory findings in that P-gp expression has been associated with tumour progression. In the present study, we characterized P-gp-positive and P-gp-negative single-cell clones of a murine osteosarcoma, to further investigate the relationship between P-gp expression and changes in cell phenotype. Although these clones were all selected by doxorubicin (DOX) exposure, they were heterogeneous with respect to MDR1 gene expression. The P-gp-positive clones revealed MDR phenotype, whereas the P-gp-negative clones showed no resistance to drugs. Morphological and functional analysis showed that both the P-gp-positive and P-gp-negative clones were more differentiated than the parent cells in terms of enhanced activity of cellular alkaline phosphatase, an increase in well-organized actin stress fibres and enhanced osteogenic activity. Moreover, these subclones all displayed a decrease in malignant potential such as oncogenic activity, tumour growth rate and metastatic ability, regardless of their P-gp status. These results indicate that the observed osteoblastic differentiation and less aggressive phenotype in DOX-selected osteosarcoma cells may not only be explained by the direct effect of P-gp, and accordingly, consideration of the effect of DOX, as well as P-gp, appears to be important.

Photodynamic inactivation with acridine orange on a multidrug-resistant mouse osteosarcoma cell line

Overcoming multidrug resistance (MDR) is an urgent issue to improve the prognosis of osteosarcoma patients. In this study, we undertook to clarify the effect of photodynamic therapy (PDT) with acridine orange (AO) on the MDR mouse osteosarcoma (MOS / ADR1) cell line, by comparing the outcome with the effect on a chemosensitive osteosarcoma (MOS) cell line. Cultured cells of MOS and MOS / ADR1 cell lines were exposed to AO at various concentrations for various times, followed by long- or short-term (10 or 1 min) illumination with blue light (466.5 nm) for excitation. Living cells were counted by means of the trypan blue exclusion test. The results showed that AO rapidly bound to DNA, RNA and lysosomes of living MOS and MOS / ADR1 cells and also that most tumor cells in both cell lines died rapidly (viability ratio to untreated cells: 1/1000) within 48 h under conditions of continuous or 15-min flash exposure to AO at concentrations above 1.0 microg/ml plus 10-min illumination with blue light. Even after flash exposure to AO at concentrations above 1.0 microg/ml plus 1-min illumination, the viability of MOS/ADR1 cells decreased to a viability ratio of less than 1/ 1000 within 72 h. Based on these results, we concluded that AO with photo-excitation has a strong cytocidal effect, not only on chemosensitive mouse osteosarcoma cells, but also on MDR mouse osteosarcoma cells. These results suggested that photodynamic therapy with AO may be a new approach to treating MDR human osteosarcomas.

Polyploidization induced by acridine orange in mouse osteosarcoma cells

This study was undertaken to clarify the in vitro effect of acridine orange (AO) on the cell kinetics of mouse osteosarcoma cells, as well as the mechanism of cell growth inhibition induced by AO. A mouse osteosarcoma cell line (MOS), established from a radiation-induced mouse osteosarcoma, was cultured under exposure to 0.05, 0.5, 5, and 50 micrograms/ml of AO, either continuously or for 10 minutes. The cell kinetic analysis was performed using the following parameters: tumor cell growth by trypan blue exclusion test, mitotic activity, DNA synthetic activity by BrdU labeling and DNA ploidy by cytofluorometry. The results showed that continuous exposure to 5 and 50 micrograms/ml of AO or 10 minute exposure to 50 micrograms/ml of AO quickly killed the tumor cells within 12 hours, whereas continuous exposure to 0.5 microgram/ml of AO or 10 minute exposure to 5 micrograms/ml of AO gradually inhibited tumor cell growth. Under the latter conditions, mitotic activity was rapidly and completely inhibited within 48 hours but DNA synthetic activity was not completely inhibited even after 96 hours. DNA ploidy analysis demonstrated that most of the tumor cells arrested at the S-G2 phase after 12 hours, followed by G2 phase arrest after 24 hours and progressive DNA synthesis to a higher DNA ploidy class after 48 to 96 hours. We therefore concluded that a high concentration of AO has a strong cytocidal effect due to cytotoxicity whilst a moderate concentration of AO induces progressive and synchronous polyploidization by mitotic inhibition without DNA damage in MOS cells. We presume that this in vitro effect on MOS cells may be caused by protein synthetic inhibition after transfer RNA inactivation caused by AO binding.

Intracellular binding sites of acridine orange in living osteosarcoma cells

There have been many reports concerning the intracellular binding sites of acridine orange (AO), although the actual localization of AO in living cells remains controversial. This study was undertaken to clarify the intracellular localization of AO in living mouse osteosarcoma cells by cytochemical staining. A mouse osteosarcoma cell line (MOS) was cultured and continuously exposed to 0.5 microgram/ml of AO. The intracellular localization and stainability of AO the living tumor cells was morphologically detected by a high resolution fluorescence microscope. To detect the intracellular microstructure, cytochemical staining with rhodamin 123 for mitochondria, acid phosphatase for lysosome, Sudan-black for fat vesicle and toluidine blue for glucosaminoglycan were performed using fixed cells. The results showed that both the nucleus and cytoplasm of tumor cells at 10 minutes after exposure to 0.5 microgram/ml of AO emitted green fluorescence, which was especially intense in the nucleolus, but not brilliant in the nucleus and was granular orange to red fluorescence in the perinuclear particles. This stainability of AO was different from that of rhodamin 123, Sudan-black or toluidine blue, but similar to that of acid phosphatase. Based on these results, we conclude that the green fluorescence may have derived from AO binding to double stranded RNA, not to DNA, and that orange fluorescence may have derived from aggregated AO binding to lysosome.

Case report: natural development of osteosarcoma from precancerous lesion

We encountered a very rare case that suggested the natural development of osteosarcoma from a precancerous lesion. The patient presented with a huge osteosarcoma in the distal femur on the initial consultation to our hospital. He had undergone X-ray examination twice previously, due to a knee injury. The findings of the lesion detected by the first X-ray examination were similar to a fibrous cortical defect (FCD), differing from those of an osteosarcoma lesion detected by second and last X-ray examinations. We retrospectively estimated the growth rate of the FCD-like and osteosarcoma lesions and found that FCD-like lesion was not osteosarcoma, but might have been a precancerous lesion. We also speculated that this osteosarcoma lesion might have appeared 18 months before the patient consulted our hospital.

Acquisition of multidrug resistance in osteosarcomas, analyzed by doxorubicin binding assay, and histologic response to chemotherapy

BACKGROUND

The mechanism by which multidrug resistance is acquired in human osteosarcomas remains unclear. In this study, we analyzed the changes in doxorubicin (DOX) binding ability (%DB), showing chemosensitivity before and after chemotherapy with DOX and cisplatin (CDDP), and evaluated the histologic response of human osteosarcomas to chemotherapy.

MATERIALS AND METHODS

Eight osteosarcomas were analyzed. %DB by the DOX binding assay was measured in fresh tumor tissues at biopsy and at resection after preoperative chemotherapy. The histologic response to chemotherapy was also evaluated.

RESULTS

Changes in %DB before and after chemotherapy were classified into 4 patterns; A: high (> 80%) to low (< 80%), B: high to high, C: low to low, D: low to high. The two tumors, classified as type A and B were responders (> 90% necrosis), whereas the 6 tumors of type C and D were classified as non-responders (< 90% necrosis). Based on these data, we speculated that the fraction of cell populations with different chemosensitivities to DOX and CDDP varied and found that type B tumors have no population of resistant cells, whereas type C tumors have a large fraction of resistant cells.

CONCLUSION

We concluded that osteosarcomas are composed of mixed cell populations with different chemosensitivities to anticancer agents and also that survival of multidrug resistant cell populations may be the most important mechanism in acquisition of multidrug resistance of osteosarcomas after chemotherapy.

Clinical outcome of total scapulectomy in 10 patients with primary malignant bone and soft-tissue tumors

BACKGROUND AND OBJECTIVES

Limb reconstruction after total scapulectomy for malignant bone and soft-tissue tumors around the scapula is difficult. This study was undertaken to clarify the clinical results of total scapulectomy in patients with malignant bone and soft-tissue tumors around the shoulder girdle in our institute between 1984 and 1998.

METHODS

Ten patients undergoing total scapulectomy had an age range of 12-82 years (average = 56 years). There were 5 cases of bone tumor and 5 cases of soft-tissue tumor. The follow-up period ranged from 8 months to 13 years 5 months.

RESULTS

Seven patients are currently alive; the remaining 3 patients died of other diseases. One case of local recurrence was detected. The 2-year survival rate of all cases was 78.8%, and the 5-year survival rate was 52.5%. The average function evaluated by Enneking's criteria was 64.6%. Although the range of motion in the shoulder joint was seriously limited in all patients, the elbow and hand functions were almost normal. Recently, we have used a bone-anchoring system to suture between the clavicle and muscles, including the biceps, triceps, and deltoid muscles.

CONCLUSIONS

Patients who undergo total scapulectomy may achieve much better upper limb function than those who undergo forequarter amputation (interscapulothoracic amputation).