Long-term outcomes of an extracorporeal irradiated autograft for limb salvage operations in musculoskeletal tumours

Aims

We analyzed the long-term outcomes of patients observed over ten years after resection en bloc and reconstruction with extracorporeal irradiated autografts

Patients and Methods

This retrospective study included 27 patients who underwent resection en bloc and reimplantation of an extracorporeal irradiated autograft. The mean patient age and follow-up period were 31.7 years (9 to 59) and 16.6 years (10.3 to 24.3), respectively. The most common diagnosis was osteosarcoma (n = 10), followed by chondrosarcoma (n = 6). The femur (n = 13) was the most frequently involved site, followed by the tibia (n = 7). There were inlay grafts in five patients, intercalary grafts in 15 patients, and osteoarticular grafts in seven patients. Functional outcome was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system.

Results

There were no recurrences in the irradiated autograft and the autograft survived in 24 patients (88.9%). Major complications included nonunion (n = 9), subchondral bone collapse (n = 4), and deep infection (n = 4). Although 34 revision procedures were performed, 25 (73.5%) and four (11.8%) of these were performed less than five years and ten years after the initial surgery, respectively. The mean MSTS score at the last follow-up was 84.3% (33% to 100%).

Conclusion

Considering long-term outcomes, extracorporeal irradiated autograft is an effective method of reconstruction for malignant musculoskeletal tumours Cite this article: Bone Joint J 2019;101-B:1151–1159

Effect of incadronate on proliferation of mesenchymal tumor cells with or without activated Ras mutation

The present investigation examined the effect of bisphosphonates on six mesenchymal tumor cell lines and the mechanisms of inhibition of tumor cell proliferation. HT-1080, a fibrosarcoma cell line that exhibits increased Ras activity due to a mutation of the Ras gene, demonstrated significantly reduced tumor cell proliferation upon treatment with incadronate. The other cell lines, however, which lack mutation of the Ras gene, showed no influence upon treatment with incadronate. Autoradiography demonstrated no difference in the uptake of 3H-labelled incadronate between susceptible and unaffected cells. The anti-proliferation of HT-1080 was reversed by the addition of geranylgeranyl pyrophosphate. Etidronate exhibited no influence on all tested cell lines. On the basis of these data, we hypothesized that incadronate inhibits the mevalonate pathway and blocks oncogenic Ras signaling. In an effort to confirm this hypothesis, the influence of incadronate on an oncogenic Ras transfected BALB/3T3 cell line (Bhas 42) and a parental BALB/3T3 cell line were compared. The parental BALB/3T3 cells showed slight inhibition upon treatment with incadronate, however, the proliferation of Bhas 42 cells was significantly reduced. These results suggest that incadronate suppresses oncogenic Ras-activated mesenchymal tumors through the inhibition of Ras signaling pathways.

Congenital dermatofibrosarcoma protuberans with fibrosarcomatous and myxoid change

This report describes a case of congenital dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous (FS) and myxoid areas. Immunohistochemical results showed that tumour cells in ordinary DFSP areas were diffusely positive for CD34, whereas in the FS and myxoid areas, few tumour cells were positive for this antigen. Ki-67 positive tumour cell numbers were greater in the FS (11.8%) and myxoid areas (19.8%) relative to ordinary DFSP areas (2.2%). Reverse transcription polymerase chain reaction and sequence analysis showed the presence of an identical COL1A1-PDGFB fusion transcript in ordinary DFSP (plaque-like area), FS, and myxoid areas of DFSP. These results indicate that the three components of DFSP have a common histogenesis. This study documents the first application of gene analysis involving the myxoid area of DFSP.

Extracorporeal irradiated autogenous osteochondral graft

We examined osteochondral autografts, obtained at a mean of 19.5 months (3 to 48) following extracorporeal irradiation and re-implantation to replace bone defects after removal of tumours. The specimens were obtained from six patients (mean age 13.3 years (10 to 18)) and consisted of articular cartilage (five), subchondral bone (five), external callus (one) and tendon (one). The tumour cells in the grafts were eradicated by a single radiation dose of 60 Gy. In three cartilage specimens, viable chondrocytes were detected. The survival of chondrocytes was confirmed with S-100 protein staining. Three specimens from the subchondral region and a tendon displayed features of regeneration. Callus was seen at the junction between host and irradiated bone.

Treatment of pathological fracture of the femur due to diffuse haemangioma in the lower limb

We describe two patients with a diffuse haemangioma of the lower limb complicated by pathological fracture of the femoral shaft, one of whom was treated by a bone graft and immobilisation in a cast, and the other by external fixation and injection of bone marrow. A review of the literature identified difficulty in control of bleeding and obtaining bony union.

Painful Schmorl's node treated by lumbar interbody fusion

STUDY DESIGN

A case report of painful lumbar Schmorl's node is presented.

OBJECTIVE

To describe diagnostic evidence and the result of surgical treatment of a rare case of painful Schmorl's node.

SETTING

Niigata, Japan.

CASE REPORT

A 55-year-old housewife was diagnosed with painful Schmorl's node of L3 by discography, which depicted leakage of the contrast medium into the L3 vertebra through a disruption of the central part of the cranial end plate with concomitant back pain. Segmental fusion surgery was performed. Mechanical low back pain of the patient improved just after surgery. Histologic examination demonstrated that fibrocartilaginous tissue herniated through a disruption of the superior end plate and forced into the vertebral spongiosa.

CONCLUSIONS

Painful Schmorl's node can be diagnosed by discography, which demonstrates an intravertebral disc herniation with concomitant back pain. Surgical treatment should be considered in a patient with persistent disabling back pain. When surgical treatment is indicated, eradication of the intervertebral disc including Schmorl's node and segmental fusion are preferable.

Coxsackievirus and adenovirus receptor (CAR)-positive immature osteoblasts as targets of adenovirus-mediated gene transfer for fracture healing

Adenovirus vectors are expected to be a powerful tool for gene therapy to treat severe fractures. Adenovirus invades cells through binding to the coxsackievirus and adenovirus receptor (CAR) on the cell membrane. CAR expression is low in normal adult animals, but it is induced on regenerating cells in some experimental models. We made a rib fracture model in mice and evaluated the histological changes and CAR mRNA expression by RT-PCR 1, 5, 10, 14, and 21 days after the fracture. CAR mRNA was expressed exclusively in the fractured ribs at each time point, but not in the normal ribs. We detected the CAR protein immunohistochemically in fibroblast-like cells in the fracture callus on days 10 and 14 after fracture. In situ hybridization showed that these fibroblast-like cells expressed mRNA of type I collagen and osteopontin, but not osteocalcin, defining the cells as immature osteoblasts. We then transferred small doses (10(4)-10(8) PFU) of lacZ-expressing adenovirus vector into immature osteoblasts on day 14. beta-galactosidase was detected only on the immature osteoblasts at every dose. Immature osteoblasts play an important role in the matrix replacement step in fracture healing. CAR-mediated gene transfer into immature osteoblasts can be reasonable for adenovirus-mediated treatment of fracture healing.

Treatment of myxoid liposarcoma by marginal or intralesional resection combined with radiotherapy

Local recurrence-free survival rate for myxoid liposarcoma (MLS) is related to negative surgical margins. The goal of surgery in the treatment of MLS is to obtain tumor-free surgical margins. When a tumor is adjacent to critical structures, wider resection, which can result in amputation, would be selected for local control. While recognizing that marginal or intralesional resection is associated with high risk of recurrence, circumstances occur that lead surgeons to conduct conservative surgery. To determine whether marginal or intralesional resection combined with radiotherapy can achieve local control, 10 cases (12 tumors) were reviewed involving MLS treated with marginal (8 tumors) or intralesional resection (4 tumors) followed by postoperative radiotherapy (50-70 Gy, average 59.2 Gy). No recurrences of MLS were observed locally at the mean follow-up of 58.1 months. The development of severe radiation-related complications was not detected. This medium follow-up study suggested that this method can achieve a high rate of local control.

Increase in serum 1,25-dihydroxyvitamin D and hypercalcaemia in a patient with inflammatory myofibroblastic tumour

Hypercalcaemia complicates the clinical course of a substantial number of patients with advanced cancer. This report describes a patient with an inflammatory myofibroblastic tumour in soft tissue who developed an inflammatory reaction, hypercalcaemia, and a high serum concentration of 1,25 dihydroxyvitamin D. Serum concentrations of 25-hydroxyvitamin D, parathyroid hormone, and parathyroid hormone related protein were normal. Histological examination of the tumour revealed fibrosarcoma with abundant macrophage infiltration. mRNA for 25-hydroxyvitamin D-1alpha-hydroxylase was identified in the tumoral tissue. In view of this case, inflammatory myofibroblastic tumour should be added to the list of diseases that are responsible for vitamin D mediated hypercalcaemia.

A PCR-ELISA assay for the detection of disseminated osteosarcoma cells in a mouse metastatic model

Circulating tumor cells in the blood play a central role in the metastatic process. There have been no reports describing the relationship between lung metastasis and circulating osteosarcoma cells. We developed a system with a polymerase chain reaction assay based on an enzyme-linked immunosorbent assay (PCR-ELISA) to detect circulating osteosarcoma cells in a mouse metastatic model. Osf2/Cbfa1, hereafter called Osf2, a member of the runt family of transcription factors, was used as a target gene. One splicing variant of Osf2 mRNA was identified and its expression was restricted to the bones and osteosarcomas. The amount of the splicing variant of Osf2 mRNA was significantly higher in the blood of mice with metastasis than in the blood of the control group. The PCR-ELISA using Osf2 mRNA is a potential method to detect circulating osteosarcoma cells in peripheral blood.

Myxoid liposarcoma metastatic to the thoracic epidural space without bone involvement: report of two cases

Myxoid liposarcoma can frequently metastasize to extrapulmonary sites. We present two cases of myxoid liposarcoma metastatic to the epidural space. Both patients complained of back pain, but plain radiography revealed no abnormality. MR imaging clearly demonstrated metastatic tumors in the epidural space, but no involvement of vertebra. When patients with myxoid liposarcoma complain of back pain, metastasis in the epidural space should be considered even in patients without bone involvement.

Presacral schwannoma with purely cystic form

STUDY DESIGN

Case report.

OBJECTIVE

To point out that presacral schwannoma can display markedly cystic degeneration.

SUMMARY OF BACKGROUND DATA

Benign schwannoma sometimes displays degenerative changes, such as cyst formation, calcification, hemorrhage, and hyalinization. Usually these degenerations are partially seen in the tumors.

METHODS

Medical history, physical findings, imaging features, and histologic findings were reviewed in a case with a large presacral schwannoma.

RESULTS

A 62-year-old woman presented with an 18-month history of right sciatic pain. Magnetic resonance images detected a large cystic, presacral tumor. Initially the tumor was misdiagnosed as a cystic ovarian tumor. Preoperative diagnostic workup led to the diagnosis of cystic schwannoma. Intralesional curettage achieved good pain relief.

CONCLUSIONS

This tumor was unusual in its totally cystic appearance and resemblance to a cystic ovarian tumor or anterior sacral meningocele. Preoperative diagnosis is important to prevent major neurologic deficit at surgery.

Retroperitoneal malignant peripheral nerve sheath tumor associated with scoliosis in neurofibromatosis

Neurofibromatosis 1 is an autosomal dominant disorder characterized by distinctive clinical problems including scoliosis and malignant peripheral nerve sheath tumors. We present two cases of retroperitoneal malignant peripheral nerve sheath tumor associated with scoliosis in neurofibromatosis. Presence of spinal deformity resulted in delay of the diagnosis of the sarcoma.

Intra-abdominal metastases in musculoskeletal sarcomas

This study examined the incidence, histological type, clinical symptoms, and prognosis in patients with intra-abdominal metastases of musculoskeletal sarcomas. The medical records of 505 patients with musculoskeletal sarcomas were reviewed for examples of intra-abdominal metastases. The incidence of intra-abdominal metastases (excluding lung) was: 4% in the liver (20 patients), 1.2% in gastrointestine (6 patients), 0.8% in pancreas (4 patients), and 0.8% on the peritoneal surface (4 patients). Patients with a previous hisory of lung metastases and those with high-grade liposarcoma tended to show metastasis in the intra-abdominal organs. Most patients with liver metastasis had no symptoms. Patients with gastrointestinal metastasis had abdominal pain, anemia, and melena. Patients with pancreatic metastasis had diabetes and jaundice. Six patients underwent surgical treatment, and two of them survived for more than 2 years. Metastases within the abdomen must be considered as a possible site for dissemination of musculoskeletal sarcomas, especially in patients with advanced disease and those with liposarcoma.

Recurrent malignant variant of phosphaturic mesenchymal tumor with oncogenic osteomalacia

Phosphaturic mesenchymal tumor is a rare neoplasm which causes osteomalacia or rickets. The tumor typically follows a benign clinical course. Even in the rare malignant cases, local recurrence and distant metastasis are uncommon. We report on an example of a malignant phosphaturic mesenchymal tumor which recurred several times over 16 years concurrently causing hypophosphatemia, bone pain, and osteomalacia. Following each surgery, symptoms and hypophosphatemia improved. The patient died of disease 17 years after the first surgery. Histologically, the initial tumor was composed of small spindle cells with clusters of giant cells, prominent blood vessels, poorly formed cartilaginous areas, and crystalline material. Cytological atypia was minimal. Following multiple recurrences, the tumor demonstrated areas of high-grade sarcoma exhibiting marked pleomorphism, numerous mitotic figures, and p53 overexpression. This case illustrates the potential lethality of incompletely removed phosphaturic mesenchymal tumors.

Elevation of serum alkaline phosphatase in clear cell chondrosarcoma of bone

BACKGROUND

Clear cell chondrosarcoma is a rare bone tumor, which is sometimes misdiagnosed as a different bone neoplasm.

MATERIALS AND METHODS

The files of 6 patients with clear cell chondrosarcomas were reviewed. Histological slides, radiographic studies, and pre- and post-operative serum alkaline phosphatase (ALP) levels were evaluated. Molecular and histochemical analyses of ALP were documented in one case of clear cell chondrosarcoma.

RESULTS

Pre-operative serum ALP levels were elevated in 3 patients, and were normal in another 3 patients. After removal of the tumors, the enzyme levels decreased in all patients and returned to normal in 3 patients, who had pre-operative high ALP levels. Enzyme histochemical and molecular analyses demonstrated that the tumor produced ALP.

CONCLUSION

Clear cell chondrosarcoma produces ALP, which can be used as a tumor marker in diagnosis and follow-up.

Solitary osseous hemangioma outside the spinal and craniofacial bones

Bone hemangioma is mainly seen in the skull and spine, and rarely occurs in other bones. We report herein four cases of osseous hemangioma arising in rare sites: In two cases, on a rib; a faintly painful mass in one case located on the scapula; and progressive pain in one case located on the ischium. The tumors presented clinically as incidental lesions on radiographs. All cases had an aggressive appearance, such as defect of the cortex, a soft-tissue mass, and a sunburst-like appearance. Markedly high signal intensity on T2-weighted magnetic resonance images was a characteristic finding. Open biopsy resulted in severe blood loss, but needle biopsy was performed safely under computed tomography guidance. It is important to note that bone hemangiomas may be misdiagnosed as malignant tumors.

Deep-seated segmental neurofibromatosis without café au lait spots

Segmental neurofibromatosis is a rare disease characterized by neurofibromas with or without café au lait spots localized to one segment of the body. The majority of reported cases have had cutaneous neurofibromas, and patients with deep involvement have rarely been described. We report on two patients with deep-seated segmental plexiform neurofibromatosis and review the literature. All reviewed cases including the present two had no café au lait spots, axillary freckling, Lisch nodules, family history or malignant progression of disease. Differential diagnoses from neuro-fibromatosis 1 (von Recklinghausen disease) and malignant peripheral nerve sheath tumor are important for genetic counseling and avoiding overtreatment.

Collagenous fibroma of the arm: a report of two cases

A recently proposed addition to fibrous tumors in soft tissue was first described as desmoplastic fibroblastoma and later renamed collagenous fibroma. This tumor is clinically and morphologically distinct and benign. However, only a few series have been reported, and the clinicopathologic features are not widely recognized. We present two cases of collagenous fibroma of the arm. Both patients presented with an enlarging, well-circumscribed and mobile soft tissue mass. Magnetic resonance imaging showed areas of low signal intensity on both T1- and T2-weighted sequences. Needle aspiration cytology revealed nondiagnostic samples because of the low cellularity of the tumors. Each of the resected tumors was composed of low-cellular spindle- to stellate-shaped cells in a fibrous matrix with clear margination. After the marginal excisions, no recurrences were observed. Clinicians should be aware of this entity to prevent overtreatment, because imaging findings and cytologic features are similar to those of desmoid tumor.

Well-differentiated liposarcoma of the hand. Case report

Malignant lipomatous tumours of the hands are extremely rare. A 62-year-old man complained of an enlarging, soft, painless mass in his left hand. Magnetic resonance imaging showed a fatty tumour with irregular septa, and an incisional biopsy showed it to be a well-differentiated liposarcoma. The tumour was resected en bloc and he had a course of external beam radiotherapy. Apart from a slight reduction in grip strength he was well 15 months later with no sign of recurrence.

Repeated dedifferentiation of low-grade intraosseous osteosarcoma

Low-grade intraosseous osteosarcoma is an uncommon bone tumor that is characterized by minimum cytological atypism and a much better prognosis than conventional osteosarcoma. This report describes a patient who had a low-grade osteosarcoma that mimicked fibrous dysplasia (FD). The tumor had an area of high-grade sarcoma at the initial diagnosis. Ten years after incomplete resection of FD-like tumor, local recurrence with areas of high-grade tumor developed. This case illustrates the potential of dedifferentiation in low-grade intraosseous osteosarcoma.

Simultaneous anterior-posterior approach for excision of malignant paraspinal tumor and subsequent reconstruction. Technical note

In cases of primary malignant extradural tumors of the spine, the main goal of the surgery is en bloc resection and reconstruction of the spine. After placing the patient in the lateral position, an en bloc resection of a chondrosarcoma that arose from the right seventh rib head and invaded the adjacent vertebra was performed using a simultaneous anterior-posterior approach followed by spinal reconstruction. The technical details are reported. Paraspinal malignant tumors of the thoracic spine can be safely removed en bloc and the spine reconstructed using this approach.

Osteosarcoma metastatic to the kidneys without lung involvement

Symptomatic renal metastasis is very rare in osteosarcoma. A few reported cases had pulmonary metastases before renal involvement. We present a case of metastatic renal osteosarcoma without pulmonary involvement. The patient presented with hematuria 8 years after initial treatment of osteosarcoma of the left distal femur. Computed tomography revealed a bilateral calcified renal mass. The patient died of disease 4 months after detection of the metastases. At autopsy, metastatic osteosarcoma was discovered in the bilateral kidney, both renal veins, inferior vena cava and right atrium. There was no pulmonary involvement. We emphasize the need for renal evaluation for the follow-up of patients with osteosarcoma.

Solitary infantile myofibromatosis involving the clavicle

A rare case of solitary infantile myofibromatosis of bone is reported in the right clavicle of a 15-year-old boy. A radiograph demonstrated an osteolytic lesion with a sharp margin and a sclerotic rim. CT revealed a circumscribed lesion with slight expansion of the cortex. On MRI the lesion appeared isointense to muscle on T1-weighted images, bright on T2-weighted images, and showed marked gadolinium enhancement. The patient was well, without evidence of recurrence or metastasis, 4 years and 5 months following resection.

Brain metastases in musculoskeletal sarcomas

BACKGROUND

In musculoskeletal sarcomas, brain metastases are rare, but severely affect quality of life.

METHODS

All patients with musculoskeletal sarcomas who were treated at our institutions from 1975 to 1997 were reviewed for examples of brain metastasis.

RESULTS

Of 480 sarcoma patients, 179 had distant metastases, including 20 patients with brain metastases (4.2%). Alveolar soft part sarcoma (3/4), extraskeletal Ewing's sarcoma (2/8), rhabdomyosarcoma (2/13) and bone Ewing's sarcoma (2/18) tended to metastasize to the brain. All 20 patients had distant or local relapses and 16 of the 20 patients had pulmonary metastases. Three patients underwent surgical treatment and two of them survived over 1 year. Mean survival after diagnosis of brain metastasis was 5.1 months.

CONCLUSIONS

Patients with alveolar soft part sarcoma, Ewing's sarcoma, rhabdomyosarcoma and pulmonary metastases have a high risk of brain metastasis.

Tumors of peripheral nerves: correlation of symptoms, clinical signs, imaging features, and histologic diagnosis

OBJECTIVE

To distinguish between benign and malignant tumors in the peripheral nerves.

DESIGN AND PATIENTS

The clinical, imaging and histologic findings of 99 benign and 16 malignant tumors in the peripheral nerves were reviewed retrospectively.

RESULTS

Preoperative motor weakness was observed in only six of 99 benign tumors and was mild, while slight to severe motor weakness was present in 15 of 16 malignant lesions. Pain at rest was present in five of 99 benign tumors and in 15 of 16 malignant tumors. All benign lesions showed a smooth tumoral margin, while half the malignant lesions showed an invasive margin on CT or MRI. Thirteen of 28 benign lesions on CT and nine of 23 on MRI showed round to geographic central enhancement, but this pattern was not seen in malignant lesions.

CONCLUSION

Absence of severe motor weakness and a central enhancement pattern strongly suggest a benign nature, while severe rest pain and invasive tumor margin suggest malignant lesions in peripheral nerve tumors.

Extraskeletal Ewing's sarcoma mimicking traumatic hematoma

We describe the clinical course of a 16-year-old baseball player with a history of recurrent hematoma of the thigh. The lesion was aspirated percutaneously several times and curetted under the diagnosis of traumatic hematoma. Microscopical examination revealed massive hemorrhage, necrosis, and a small number of Ewing's sarcoma cells. He died of multiple metastases. With recurrent hematoma in the soft tissue, neoplastic lesions should be ruled out.

Origin of histiocyte-like cells and multinucleated giant cells in malignant fibrous histiocytoma: neoplastic or reactive?

The origin of histiocyte-like cells in malignant fibrous histiocytoma (MFH) remains controversial. To determine whether histiocyte-like cells and multinucleated giant cells show reactive or neoplastic proliferation, we transplanted human storiform-pleomorphic MFH to nude mice and investigated the origin of histiocyte-like cells using the DNA in situ hybridization (ISH) system. In addition, we analyzed the mRNA expression of mouse c-fms and human colony stimulating factor-1 (CSF-1); immunohistochemical expression of markers detectable in cells of monocyte/macrophage lineage. The DNA ISH revealed neoplastic proliferation of fibroblastic cells and bizarre multinucleated giant cells of human origin. Monocyte/macrophage lineage cells were seen in parental tumors, whereas they did not participate in neoplastic proliferation in transplanted tumors. The parental tumors expressed human CSF-1 mRNA and the histiocyte-like cells in transplanted tumors expressed 'mouse' c-fms mRNA. These results suggest that MFH induce infiltration of monocyte/macrophage and CSF-1 is one of the mediators involved in this phenomenon, because the human CSF-1 can act as a ligand to the mouse c-fms. Histiocyte-like cells in MFH should be considered as a reactive monocyte/macrophage lineage rather than as an element of neoplasm.

Bone tumors of the coracoid process of the scapula

Bone tumors of the coracoid process of the scapula are rare, and diagnosis and treatment often are delayed. The records of 18 patients with bone tumors of the coracoid process were reviewed. Histologic types included eight cases of ordinary chondrosarcoma, three cases of dedifferentiated chondrosarcoma, two cases of osteoid osteoma, and one case each of osteosarcoma, plasmacytoma, lymphoma, giant cell tumor, and aneurysmal bone cyst. All 18 patients had shoulder pain, and eight of them had been treated with steroid injections for nonneoplastic conditions. Radiologically, chondrosarcoma did not always show clear cortical destruction, and one giant cell tumor had features mimicking those of chondrosarcoma. Five patients (three with dedifferentiated chondrosarcoma, one with chondrosarcoma, one with plasmacytoma) died of disease. The coracoid process was the site with a markedly high proportion of chondrosarcomas. Bone tumors of the coracoid process may be difficult to detect on plain radiographs. In the patient with persistent shoulder pain unresponsive to the selected treatment, additional imaging studies should be considered to eliminate the possibility of a bone lesion.

Characterization and chemosensitivity of two human malignant peripheral nerve sheath tumour cell lines derived from a patient with neurofibromatosis type 1

Two new cell lines, designated NMS-2 and NMS-2PC, were established in vitro from a malignant peripheral nerve sheath tumour (MPNST) in the right thigh and a retroperitoneal lesion of a 30-year-old man with neurofibromatosis type 1 (NF1). The NMS-2 cell line was derived from the first tumour, and the NMS-2PC cell line from a retroperitoneal metastatic tumour detected 9 months later. Cultured NMS-2 cells showed epithelioid features, while NMS-2PC cells showed fibroblast-like features. However, both cell lines were strongly positive for S-100 protein. The transplanted NMS-2 and NMS-2PC tumours showed the same histological features typical of MPNST. Chromosomal analysis revealed that only the NMS-2 cells had a t (1;2) chromosomal translocation. Chemosensitivity tests demonstrated that NMS-2PC cells were far more sensitive than NMS-2 cells to Adriamycin and etoposide, which had been used clinically. All-trans-retinoic acid induced a morphological change in NMS-2PC cells so that they were no longer fibroblast-like, but epithelioid cells. We believe the epitheloid components in the MPNST were derived from typical spindle cells.

Ossifying fibromyxoid tumor resembling parosteal osteosarcoma

Ossifying fibromyxoid tumor (OFMT) is a rare soft tissue neoplasm which varies in the amount of bone tissue laid down. We report on a case of OFMT in a 59-year-old male which mimicked a large parosteal osteosarcoma on radiography, MRI, and CT. T1-weighted MR images showed high-intensity areas which reflected fatty marrow. The metaplastic bone was connected to the cortex of the femur, but the tumor did not involve the medullary cavity. The tumor was irradiated and the patient was administered chemotherapy. Wide excision of the tumor and hip rotation plasty was performed. The patient has been disease free for 18 months.

Malignant melanoma extending along the ulnar, median, and musculocutaneous nerves: a case report

We analyzed a case of malignant melanoma that resembled malignant peripheral nerve sheath tumor with marked neurotropism. The subungual tumor in the right ring finger extended along the ulnar nerve for a distance of 30 cm, as well as along the median and musculocutaneous nerves, with lymph nodal metastases. The tumor consisted of interlacing spindle-shaped cells with large nuclei and distinct nucleolei. Immunohistochemically, the tumor cells were diffusely positive for S-100 protein. Five years after forequarter amputation, the patient is alive without disease. Malignant melanoma has the potential of invading several major peripheral nerves and must be distinguished from malignant peripheral nerve sheath tumor, which rarely metastasizes to regional lymph nodes.

Multiple schwannomas in the peripheral nerves

Multiple tumours of peripheral nerves are often seen in patients with neurofibromatosis of type 1 or 2. Multiple schwannomas may occur without other manifestations of neurofibromatosis. We have reviewed 12 patients with multiple schwannomas arising from peripheral lesions who did not fulfil the criteria for either type of neurofibromatosis. Four had spinal and one an intracranial lesion in addition to the peripheral tumours. Two patients had one and three café-au-lait spots, respectively, and another had a probable family history. The largest tumours were 45 to 250 mm in size. Three patients had been referred as having von Recklinghausen's disease. The large size of tumours, the difficulties of histological diagnosis on biopsy, and the confusion with neurofibromatosis can lead to overtreatment. Malignant change seldom, if ever, occurs in patients with multiple schwannomas.

Multiple schwannomas in the peripheral nerves

Multiple tumours of peripheral nerves are often seen in patients with neurofibromatosis of type 1 or 2. Multiple schwannomas may occur without other manifestations of neurofibromatosis. We have reviewed 12 patients with multiple schwannomas arising from peripheral lesions who did not fulfil the criteria for either type of neurofibromatosis. Four had spinal and one an intracranial lesion in addition to the peripheral tumours. Two patients had one and three café-au-lait spots, respectively, and another had a probable family history. The largest tumours were 45 to 250 mm in size. Three patients had been referred as having von Recklinghausen's disease. The large size of tumours, the difficulties of histological diagnosis on biopsy, and the confusion with neurofibromatosis can lead to overtreatment. Malignant change seldom, if ever, occurs in patients with multiple schwannomas.

Origin of bone-forming cells in human osteosarcomas transplanted into nude mice--which cells produce bone, human or mouse?

Osteosarcomas are malignant tumours producing osteoid and/or bone. It is difficult to distinguish tumour bone formation from reactive, based on their morphological features alone. The objective of this study was two-fold: to clarify the origins of bone-forming cells in human osteosarcoma transplanted into nude mice; and to examine the role of bone morphogenetic proteins (BMPs) in the tumour-induced osteogenesis. DNA in situ hybridization was carried out with digoxigenin (DIG) polymerase chain reaction (PCR) labelled DNA probes for human-specific 'Alu' and mouse-specific 'mouse L1 (m-L1)' genes. Human osteosarcoma cells, established cell lines of NOS-1, NOS-2, and HuO9, were transplanted separately into nude mice. Bone-forming cells of the bone in the NOS-1 or NOS-2 tumours were positive for Alu, while they were negative for m-L1. The cells lining the surface of trabeculae in the HuO9 tumour were positive for Alu, but a few of them were also positive for m-L1. The m-L1-positive cells expressed mouse osteocalcin and type 1 collagen mRNAs. These facts suggest that the mouse cells were involved in osteoid synthesis of the HuO9 tumour. The NOS-1 or NOS-2 tumours expressed human BMP 2-7 mRNAs, whereas the HuO9 tumour expressed human BMPs 2, 4, 5, and 7. The osteogenetic potential of the tumours may depend on the expression patterns of BMPs. These results demonstrate two distinct types of bone formation, by tumour cells and by an admixture of tumour and non-tumour cells. The present study showed that the HuO9 tumour produces chimeric bone formation. This is the first report to demonstrate the relationships between tumour cells and non-tumour cells in bone formation, using genetic markers.

Chondrosarcoma of small bones of the hands and feet

BACKGROUND

Cartilaginous tumors of the hands and feet are not uncommon. Most are enchondromas, but they tend to show high cellularity, enlargement of nuclei, and many double-nucleated cells. Hence, differentiation between a benign lesion and chondrosarcoma may be difficult.

METHODS

The files of patients treated at the Mayo Clinic and the consultation files were reviewed for examples of chondrosarcoma of small bones of the hands and feet. Histologic features and clinical charts were reviewed in all cases, and radiographs were reviewed in 111 cases.

RESULTS

Seventy-five lesions involved the feet and 88 involved the hands. Bones of the fifth finger and the calcaneus were the most common sites of involvement. Nineteen tumors were secondary. Of the 104 intramedullary lesions studied radiologically, 96 showed cortical destruction, 83 a soft tissue mass, and 52 a permeative lytic pattern. Histologically, soft tissue extension and permeation of preexisting bone indicated malignant disease. One hundred sixteen tumors were Grade 1, 44 were Grade 2, and 3 were Grade 3. Of the 12 patients with distant metastasis from chondrosarcoma, 7 died of disease. Chondrosarcomas of the calcaneus and the talus were more likely to metastasize.

CONCLUSIONS

Chondrosarcoma of small bones of the hands and feet has the potential to be fatal.

Periosteal chondrosarcoma invading the medullary cavity

We present a case of periosteal chondrosarcoma of the femur, in which a tumor invaded the medullary cavity and the lesion was clearly demonstrated only on MRI. To the best of our knowledge, there have been no previous reports of an intramedullary lesion caused by periosteal chondrosarcoma demonstrated on MRI.

Human osteosarcoma (OST) induces mouse reactive bone formation in xenograft system

To distinguish the origin of bone-forming cells in the osteosarcoma (OST) tumor inoculated into nude mice, we have developed a novel in situ hybridization technique. The system used digoxygenin (DIG) labeled DNA probes that encoded human specific repetitive gene, Alu, and mouse specific repetitive gene, mouse L1 (m-L1). The chondrogenic and osteogenic cells in the tumor had strongly positive signals for m-L1 probe without any signals for Alu probe. The expression of bone matrix proteins was also examined by in situ hybridization. The bone-forming cells were positive for mRNAs of mouse osteonectin, osteopontin, and osteocalcin relating to calcification during bone formation, while these were negative for human mRNAs of these bone matrix proteins. The OST cells in the tumor expressed the human bone morphogenetic proteins (BMPs) mRNAs by RT-PCR. These data indicated that the mouse cells, not the human sarcoma cells, are responsible for cartilage and bone formation in the OST tumor inoculated into nude mice, and we speculated that BMPs, at least in part, could play an important role in this ossification.

Ossifying fibromyxoid tumor of the retroperitoneum

A case of ossifying fibromyxoid tumor (OFMT) in an unusual site, the retroperitoneum, in a 71 year old Japanese man is reported. The well demarcated tumor contained a large amount of mature bony tissue within the tumor. The tumor cells were round to spindle-shaped, and showed a high cellularity in some areas and were loosely arranged in other areas. Although the majority of tumor cells expressed vimentin, neuron specific enolase and Leu-7, there were no tumor cells positive for S-100 protein, myogenic or epithelial markers. We would like to emphasize that tumors classified as OFMT contain a wide spectrum of histologic features and heterogeneity.

Expression of bone morphogenetic proteins in human osteogenic and epithelial tumor cells

In addition to osteosarcomas some epithelial tumors also show bone induction, which is supposedly due to bone morphogenetic proteins (BMPs). However, the types of BMPs expressed in different kinds of tumors have not been studied extensively. In this study five human osteosarcoma and six human carcinoma cell lines were examined to investigate the bone induction and BMP mRNA expression. The cultured cells were transplanted in the subcutaneous tissue of athymic nude mice with or without diffusion chambers. Reverse transcription-polymerase chain reaction (RT-PCR) was used for the detection of BMP mRNAs. All osteosarcoma cell lines expressing all BMPs (BMP-1 to 7) examined, successfully formed bone or osteoid tissue irrespective of the use of a diffusion chamber. Bone formation was induced by diffusion chamber in an osteosarcoma cell line OST and a gastric adenocarcinoma cell line MKN45. OST cells lacked BMP-3 and 7, and MKN45 cells lacked BMP-3, 5 and 6. Our data suggest that BMP-3, 5, 6 and 7 are not always essential for bone induction in tumor cells.

Clear cell chondrosarcomas arising from rare sites

Three cases are reported of clear cell chondrosarcoma arising from unusual sites: talus, rib and vertebra. Radiographically, two tumors showed osteolytic features and the vertebral tumor showed osteoplastic change. Histologically, all tumors consisted of clear cells that had a centrally placed nucleus surrounded by clear cytoplasm, osteoclast-like giant cells, areas of conventional chondrosarcoma, and various amounts of reactive bone. The tumor in the talus was initially diagnosed as benign chondroblastoma, but it recurred. The rib tumor showed marked cystic formation stimulating aneurysmal bone cyst. The osteoplastic radiographic feature in vertebral tumor was considered to be due to the abundant bone formation.

In vitro differentiation and proliferation in a newly established human rhabdomyosarcoma cell line

A newly established cell line, designated NRS-1, was derived from an alveolar rhabdomyosarcoma that developed in the left forearm of a 7-year-old girl. The cell line had a t(2; 13) chromosomal translocation. Reverse transcription-polymerase chain reaction demonstrated that 5' PAX3-3' FKHR chimeric transcript was expressed in NRS-1 cells. NRS-1 cells showed myogenic differentiation without any particular stimulus in vitro and exhibited various kinds of muscle markers. All-trans retinoic acid promoted cell differentiation in the myogenic direction. Transforming growth factor-beta (TGF-beta) inhibited myogenic differentiation of those cells and promoted cell proliferation.

Bone formation in vitro and in nude mice by human osteosarcoma cells

Osteosarcomas contain variable amounts of bony tissue, but the mechanism of bone formation by osteosarcoma is not well understood. While a number of cultured human osteosarcoma cell lines have been established, they are maintained by different media and differ qualitatively with regard to bone formation. We examined different media for their ability to support bone formation in vitro and found the alpha-modification of Eagle's minimal essential medium supplemented with beta glycerophosphate was best for this purpose, because it contained the proper calcium and phosphate concentrations. Subsequently, we compared seven human osteosarcoma cell lines under the same experimental conditions to clarify their ability to induce bone formation. NOS-1 cells most frequently exhibited features of bone formation in vitro and in nude mice. Collagen synthesis by tumour cells themselves seemed to be the most important factor for bone volume. However, even HuO9 cells, which lacked collagen synthesis and failed to form bone in vitro, successfully formed tumours containing bone in nude mice. Histological analysis of HuO9 cells in diffusion chambers implanted in nude mice and the findings of polymerase chain reaction indicated that the phenomenon was probably due to bone morphogenetic protein.