Dedifferentiated chondrosarcomas arising in preexisting osteochondromas

BACKGROUND

Dedifferentiated chondrosarcomas that arise in osteochondromas are extremely rare lesions for which very little information on treatment and outcome is available in the literature. The purpose of the present study was to describe the specific clinical, radiographic, and histologic features of this lesion and to evaluate the oncologic outcome after different treatment strategies.

METHODS

We reviewed the files of the Rizzoli Institute between 1970 and 2002 and identified eighteen patients for whom adequate records and histologic images were available and in whom a high-grade sarcoma had been diagnosed at the same location as a preexisting osteochondroma. Radiographic studies, histologic slides, and clinical records were reviewed, the features of those studies were tabulated, and prognostic features and the results of treatment were identified.

RESULTS

The patients included twelve men and six women with an average age of forty-six years (range, twenty-two to seventy-four years). Eight lesions occurred in patients with multiple osteochondromas, and ten occurred in patients with solitary lesions. The most common locations were the pelvis (six lesions) and the femur (five lesions). Symptoms included pain, swelling, and a growing mass; the average duration of symptoms was eighteen months. Radiographically, ten lesions appeared as a conventional secondary chondrosarcoma arising in an exostosis, whereas eight showed typical signs of dedifferentiation. Histologic evaluation of the cartilage component demonstrated thirteen grade-1 and two grade-2 chondrosarcomas. In three cases, no cartilage component was recognized. The dedifferentiated component was considered to be an osteosarcoma in nine cases (including six cases in which it was osteoblastic and three in which it was fibroblastic), a malignant fibrous histiocytoma in eight, and a fibrosarcoma in one. The dedifferentiated component represented an average of 59% (range, 20% to 100%) of the lesion. For the fifteen patients who were managed at the authors' institution, the two and five-year survival rates were 47% and 29%, respectively; the median survival time was fourteen months. Patients who were managed with a combination of surgery and chemotherapy had a better overall survival rate than did those who were managed with surgery alone (p = 0.03).

CONCLUSIONS

Dedifferentiated chondrosarcoma arising in a preexisting osteochondroma is an extremely rare lesion with a poor prognosis. In the present small series, overall survival was better when wide surgical resection was combined with adjuvant chemotherapy.

Adjuvant and neoadjuvant chemotherapy for Ewing sarcoma family tumors in patients aged between 40 and 60: report of 35 cases and comparison of results with 586 younger patients treated with the same protocols in the same years

BACKGROUND

The clinical and pathologic features of 46 patients 40 to 60 years old with Ewing sarcoma family tumor (ESFT) diagnosed at the authors' institute between 1972 and 2000 were reviewed.

METHODS

Ten patients with metastatic tumors at presentation went elsewhere for treatment; 35 of 36 remaining cases with localized disease were treated at the authors' institution according to different chemotherapy protocols activated in successive years. In patients with nonmetastatic tumors local treatment was surgery in 9 patients, radiotherapy in 16, and surgery followed by radiotherapy in 10.

RESULTS

At follow-up times ranging from 6 and 34 years (mean, 17.8 years), 15 patients (42.9%) remained continuously disease-free, 19 experienced recurrence, and 1 died of chemotherapy-related toxicity. The 5- and 10-year event-free survivals were 42.9% and 35.2%, respectively, and the 5- and 10-year overall survivals were 46.1% and 42.8%, respectively. Comparing this group of patients with 586 cases of younger patients seen in the same period at Rizzoli, the only difference between the 2 groups was a significantly higher rate of tumors located in the soft tissues with a larger volume in the older group. The results achieved were comparable in the 2 groups, although the older group had a lower chemotherapy dose-intensity and a higher rate of WHO grade 4 hematologic toxicity.

CONCLUSIONS

For patients with localized disease treated with adjuvant and neoadjuvant chemotherapy the results were essentially comparable in the 2 groups. It is concluded that patients 40 years or older with ESFT should be treated in the same way as younger patients and included in treatment trials for these tumors.

Protein expression of KIT and gene mutation of c-kit and PDGFRs in Ewing sarcomas

Ewing sarcoma is a highly malignant tumor of bone preferentially arising in children and young adults. Its 5-year survival rate is only 50% despite the use of multimodal therapeutic approaches, requiring a search for new therapeutic targets and the development of novel therapeutic modalities. KIT and PDGFRs are type III receptor tyrosine kinases, and activating mutations in c-kit (which encodes KIT) and PDGFRs have been reported as oncogenic events in many malignancies. Imatinib is a selective inhibitor of KIT, PDGFR, and ABL tyrosine kinase activity and exerts different anti-tumor effects according to the regions of mutations in c-kit and PDGFR genes. Thus, we evaluated the immunohistochemical expression of KIT protein and the mutational status of exons 9, 11, 13, and 17 of the c-kit gene, exons 12 and 18 of the PDGFRA gene, and exon 12 of the PDGFRB gene in 71 formalin-fixed, paraffin-embedded Ewing sarcomas to increase our understanding of the potential, if any, of imatinib treatment for this malignancy. Of the 71 samples, 27 (38%) were immunohistochemically positive for KIT; however, activating mutations in c-kit were found in only 2 of 71 Ewing sarcomas (2.6%) within exon 9. No activating mutations in the PDGFRA and PDGFRB genes were found, but pleomorphism was identified in exon 18 of the PDGFRA gene. Our results for KIT protein expression agree with those of previous studies. This is the largest series of c-kit mutational analysis in Ewing sarcoma to date, and the results definitively show that c-kit activating mutations are not coincident with KIT protein expression in Ewing sarcoma in most samples. These findings imply other mechanisms for KIT activity and leave open the question of whether imatinib would be efficacious in the treatment of Ewing sarcoma.

No correlation between methotrexate serum level and histologic response in the pre-operative treatment of extremity osteosarcoma

Our objectives were to evaluate the behavior of different doses of pre-operative methotrexate (MTX) pharmacokinetics, and assess correlations between the osteosarcoma histologic response and MTX serum peak concentrations. In total, 336 patients with osteosarcoma of the extremities were treated with three neoadjuvant protocols of chemotherapy including high-dose MTX (different doses for each protocol), cisplatin and doxorubicin (same doses in all protocols). The doses of MTX were 8 g/m2 in 124 patients, 10 g/m2 in 110 patients and 12 g/m2 in 102 patients. The mean value of peak serum MTX was 801 micromol/l (range 298-1831) with significant intra- and inter-patient variability. For patients treated with 8, 10 and 12 g/m2 it was 587, 735 and 1114 micromol/l, respectively (P < 0.0001). The histologic response to pre-operative chemotherapy was 90% or above tumor necrosis in 62.8% of patients and less than 90% in 37.2%. The grade of histologic response significantly correlated with the histologic subtype of the tumor, whereas no significant association was found between the mean peak of serum MTX and the histologic response. Thus, increasing the dose of MTX increases the MTX serum peaks, but does not correlate with the histologic response of the tumor.

Second malignant neoplasm in patients with osteosarcoma of the extremities treated with adjuvant and neoadjuvant chemotherapy

We evaluated the rate of second malignancies in 1205 patients with osteosarcoma of the extremity treated at our Institution with different protocols of adjuvant and neoadjuvant chemotherapy. Twenty-six patients (2.15%) developed a second malignant neoplasm at a median of 7.6 years (1 to 25 y) after primary osteosarcoma treatment. Of these, 2 developed a third cancer which were not considered in the series. Second neoplasms were leukemia (10), breast (7), lung (2), kidney (2), central nervous system cancer (2), soft tissue (1), parotid (1), and colon (1). The rate of second neoplasms was significantly higher in female patients, and the latent period shorter in hematologic tumors compared with solid tumors. Ten of these 26 patients are disease free at a median of 7.7 years (range 1 to 15 y) after the last treatment. The rate of second malignancies observed in the osteosarcoma group was significantly higher than that observed in the control group of 1160 patients with benign tumors treated in the same period at our Institute (2.2% vs. 0.8%, P<0.009). Our study showed that the risk of second neoplasm within 15 years increased and then leveled off and that although secondary solid tumors could be explained as unrelated cases, leukemias seem to be over represented.

Aggressive clear cell chondrosarcomas: do distinctive characteristics exist?: a report of 4 cases

CONTEXT

Clear cell chondrosarcoma (CCC) is commonly considered to be a low-grade subtype of chondrosarcoma. However, a few cases of CCC behave as high-grade lesions (with early metastases or multiple/synchronous locations).

OBJECTIVE

To investigate morphologic features that can help predict the aggressiveness of these CCCs.

DESIGN

To investigate possible hallmarks of this aggressiveness, we are presenting the clinicopathologic features of 6 cases of CCC, 4 of which presented aggressive features and 2 low-grade behavior. The patients were 5 men and 1 woman; their ages ranged from 22 to 47 years. Histologic appearance, ultrastructure, and immunohistochemical expression of metalloproteinase 1 and 2 and their inhibitors were evaluated in all 6 cases.

RESULTS

Pain was the most common symptom; the lesions were located in the femur (4), humerus (2), and vertebral body (1), with 1 patient presenting a double/synchronous lesion. Although no major differences were detected using conventional light microscopy, an ultrastructural analysis--at variance with usual cases--showed a lack of superficial microvilli in more than 50% of neoplastic cells in the aggressive cases, therefore suggesting a less differentiated phenotype. In addition, metalloproteinase 2 was more diffusely expressed in the aggressive tumors than in the conventional CCCs, whereas p53 labeling was always negative.

CONCLUSIONS

The aggressive behavior of some CCCs may be, at least in part, correlated to a lesser degree of cell differentiation and to the expression of tumor cell proteins, such as metalloproteinase 2, which are able to favor neoplastic spreading.

Ezrin in osteosarcoma: Comparison between conventional high-grade and central low-grade osteosarcoma

Ezrin is a cytoskeleton linker protein that is actively involved in the regulation of growth and metastatic capacity of cancer cells. Recently, it has been demonstrated that a significant correlation exists between high ezrin expression levels and the poor outcome of pediatric osteosarcoma patients. The expression of ezrin was compared in conventional high-grade and central low-grade osteosarcoma lesions to investigate the role of ezrin overexpression in the metastasis of osteosarcoma. We compared the expression levels of the ezrin protein in 32 cases of high-grade osteosarcomas and 21 cases of low-grade osteosarcomas using immunohistochemistry. Ezrin protein expression levels were examined in three different human osteosarcoma cell lines by Western blotting. In addition, the mRNA expression levels of ezrin in these osteosarcoma cell lines and control fibroblasts were evaluated by real-time quantitative PCR. Ezrin immunoreactivity was present in 43.7% of high-grade osteosarcoma specimens. All low-grade osteosarcomas were negative for ezrin. The expression of ezrin was detected by Western blotting in all three osteosarcoma cell lines. The tested osteosarcoma cell lines showed marked amplification of ezrin mRNA compared to control cells. Taken together, ezrin appears to play a role in the progression of tumors, such as the metastasis of osteosarcoma. However, further data are needed before ezrin can be considered in clinical decision-making about osteosarcoma patients.

Upregulation of the oncogenic helix-loop-helix protein Id2 in Ewing sarcoma

AIMS AND BACKGROUND

Id helix-loop-helix proteins function as regulators of cell growth and differentiation. However, they can induce malignant transformation when overexpressed. The EWS/ETS chimeric proteins in Ewing sarcoma act as aberrant transcription factors leading to tumorigenic processes. An enhanced expression of the Id2 gene in Ewing sarcoma cells was previously shown by gene array techniques. We investigated the expression of Id2 at the protein and gene level in Ewing sarcoma.

METHODS

We evaluated the expression of Id2 protein using immunohistochemistry in formalin-fixed, paraffin-embedded specimens from a total of 71 cases of Ewing sarcoma. Additionally, a Ewing sarcoma cell line was examined by real-time quantitative PCR.

RESULTS

Id2 expression was observed in 65 cases (91.5%) of the 71 total cases examined and a high level of Id2 expression was observed in 45 of these cases (63.8%). In tumor cells, Id2 proteins displayed cytoplasmic as well as nuclear localization. The amplification of the Id2 gene was not noted in a Ewing sarcoma cell line using real-time quantitative PCR. The crossing points of Id2 in the Ewing sarcoma cell line, control fibroblast, and osteosarcoma cell line were 18.54 +/- 0.16, 18.25, and 18.34, respectively.

CONCLUSIONS

Our data support a role for increased Id2 protein expression in Ewing sarcoma. However, this overexpression of the Id2 protein could not be confirmed by a corresponding change at the gene level in a Ewing sarcoma cell line.

Chordoma of the mobile spine: fifty years of experience

STUDY DESIGN

A consecutive series of 52 chordomas of the mobile spine observed over a 50-year period includes a retrospective review of 15 cases treated prior to 1991 and a prospective group of 37 cases treated from 1991 to 2002.

OBJECTIVES

This series reviews epidemiologic issues as well as clinical patterns of spinal chordomas. We attempt to correlate tumor extent, treatment, and outcomes over time.

SUMMARY OF BACKGROUND DATA

Chordoma is the most frequent primary tumor of the mobile spine. Due to slow growth, both initial symptoms and recurrences after treatment arise later, making it difficult to evaluate the effectiveness of treatment protocols.

METHODS

A prospective series of 37 cases is compared with a retrospective group of 15 patients observed between 1954 and 1991. In the prospective study, all patients had imaging studies, and oncologic and surgical staging. When en bloc resection was not feasible, intralesional extracapsular excision was combined with radiation therapy. The prospective patients were clinically evaluated and imaged. Patients in the retrospective group were evaluated by chart and available images; of these, only one en bloc resection (intralesional margin) was performed. Survivors were all evaluated clinically and had radiographic studies.

RESULTS

Forty-eight patients were available for long-term follow-up. Four died due to post-operative complications, and six due to disease less than 2 years after treatment. Forty-two patients were followed over 2 years; 26 patients had over 5 years follow-up. All patients having radiation alone, intralesional excision, or a combination had recurrences in less than 2 years, and died in some cases after a long survival with symptomatic disease. Intralesional extracapsular excision with radiation had a high rate of recurrence (12 of 16 at average 30 months), but 3 patients are continuously disease-free (CDF) at mean 52 months and 5 are alive with disease at average 69 months (ranging 24 to 146). Twelve of 18 patients having en bloc resection are CDF at average 8 years (48 to 155 months). The remaining 6 recurred and of these 1 died. All of these (6) had been previously treated and/or had en bloc resections with contaminated margins.

CONCLUSIONS

The only treatment protocol associated with CDF at follow-up longer than 5 years is margin-free en bloc resection.

Dedifferentiated central chondrosarcoma

BACKGROUND

The prognosis for patients who develop dedifferentiation of central chondrosarcoma traditionally has been poor. Because not much has been reported about this rare lesion, many uncertainties remain about prognostic factors.

METHODS

In this retrospective study, the clinical, radiographic, and histologic features and the treatments in 123 patients from the Rizzoli Institute were reviewed in an attempt to define which factors may be related to outcome in patients with dedifferentiated central chondrosarcoma.

RESULTS

Among 123 patients who were included in this study, 109 patients were treated at the Rizzoli Institute, and 14 patients were seen in consultation. There were 66 males and 57 females, and their average age was 59 years. The femur (62 patients), pelvis (28 patients), and humerus (20 patients) were the most common locations. Radiographically, a soft tissue mass was present in 87% of patients, and a bimorphic pattern was appreciated in 53% of patients. Histologically, the cartilaginous component was considered Grade 1 in 63% of patients and Grade 2 in 37% of patients. In most patients, the dedifferentiated component showed the features of an osteosarcoma (92 patients), followed by fibrosarcoma (19 patients), and malignant fibrous histiocytoma (9 patients). For 101 patients, surgery was a component of their definitive management. In 25 patients, surgery was combined with chemotherapy. The 2-year and 5-year survival rates were 34% and 24%, respectively. The median survival was 13 months (95% confidence interval, 9-17 months).

CONCLUSIONS

Metastatic disease at diagnosis, malignant fibrous histiocytoma dedifferentiation, and a high percentage of dedifferentiated component were related to poorer outcomes. There was no statistical evidence of any beneficial effect from adjuvant chemotherapy.

Overexpression of metastatic tumor antigen in osteosarcoma: comparison between conventional high-grade and central low-grade osteosarcoma

PURPOSE

The metastatic tumor antigen (MTA) gene is a recently identified metastasis-associated gene which has implications in the signal transduction or regulation of gene expression. However, the expression of MTA in osteosarcoma and its potential relationship with metastasis have not been examined, forming the basis of this study.

MATERIALS AND METHODS

We compared the expression levels of the MTA1 protein between 32 cases of high-grade osteosarcomas and 21 cases of low-grade osteosarcomas by immunohistochemistry. In addition, the mRNA expression levels of MTA1, 2, 3 in these osteosarcoma cell lines and control fibroblasts were evaluated by real-time quantitative PCR.

RESULTS

MTA1 immunoreactivity was present in 81.25% of high-grade osteosarcoma specimens. Its expression was predominantly localized to the nucleus or cytoplasm of osteosarcoma cells. Thirteen (86.6%) of 15 patients who died of osteosarcomas displayed strong MTA1 expression. Both primary bone and pulmonary metastatic lesions exhibited MTA1 expression. All low-grade osteosarcomas were negative for MTA1 except for focal weak reactivity in two cases. The tested high-grade osteosarcoma cell lines showed marked amplification of MTA1 and MTA2 mRNA compared to control cells.

CONCLUSION

These results suggest that MTA might be involved in the progression of high-grade osteosarcoma, particularly in hematogenous metastasis of osteosarcoma.

Genetic analysis of fibrosarcoma of bone, a rare tumour entity closely related to osteosarcoma and malignant fibrous histiocytoma of bone

Fibrosarcoma (FS) of bone is an extremely rare and genetically uncharacterised malignant tumour arising in the skeleton. On the basis of clinicopathologic features it appears to be closely related to either fibroblastic osteosarcoma (OS) or malignant fibrous histiocytoma (MFH) of bone. In this study, 27 decalcified, paraffin-embedded FS of bone were collected for genetic and immunohistochemical characterisation. Good quality DNA, suitable for genetic analyses, was isolated from nine cases (7 primary tumours, 1 local recurrence, and 1 lung metastasis), which were analysed by comparative genomic hybridisation (CGH) on chromosomes and DNA microarrays. DNA sequence copy number changes were found in five out of seven primary tumours (72%), as well as in both, the local recurrence and the metastatic lesion, by CGH on chromosomes. The most frequent aberration was gain of the chromosomal region 22q, which was present in four out of the five primary tumours with genetic changes, in the local recurrence and, as the sole genetic aberration, in the lung metastasis. DNA microarray analysis showed that gain of the platelet-derived growth factor beta (PDGF-B) gene (located at 22q12.3-q13.1) was the most frequent gene imbalance, which was present in three out of the five analysed tumours. In these three cases, real-time PCR revealed a 2.1- to 2.7-fold increase of PDGF-B gene copy numbers. By immunohistochemistry, a positive reaction for B-chain-containing PDGF proteins was revealed in all the cases showing gain of 22q. A more extensive immunohistochemical analysis identified the presence of PDGF-B proteins in 8/20 primary FS of bone (40%), 3/3 lung metastases and in 1/2 local recurrences. A simultaneous positive reaction for PDGF-B proteins and PDGF receptors was found in two third of PDGF-B-positive cases (8/12). Taken together, the genetic and immunohistochemical data indicate that over-representation of the chromosomal region 22q, including particularly the PDGF-B gene, may be important for the pathogenesis of FS of bone. Our results also demonstrate that CGH on chromosomes and DNA microarrays are suitable for the genetic characterisation of decalcified, paraffin-embedded tumour tissue samples and may facilitate, combined with other techniques, the rapid acquisition of data providing insight into the molecular genetic and biologic basis of rare bone sarcomas. Moreover, these findings suggest the possible presence of an autocrine loop in FS of bone, which might be taken into account for planning innovative therapeutic strategies for patients unresponsive to conventional treatments.

Primary high-grade osteosarcoma: comparison between preadolescent and older patients

The medical records of patients with high-grade osteosarcoma observed at the authors' institution between 1972 and 1999 were reviewed to study whether osteosarcoma in preadolescent patients has a different biology and a worse prognosis than in older patients. To assess epidemiologic differences, the first analysis evaluated 1,603 patients regardless of tumor stage and site and treatment received. In the second analysis, only 1,136 patients (317 preadolescent and 819 older patients) with nonmetastatic extremity osteosarcoma, treated with the same protocols of chemotherapy, were evaluated to assess differences in prognosis and in the pattern of relapse. Most preadolescents were female (56% vs. 44%, P < 0.0001), and most tumors were located in the extremity (95% vs. 5%, P < 0.001). The 5-year event-free survival (60% [95% CI 53-67%] vs. 58% [95% CI 46-63%]), the overall survival (67% vs. 65%), the rate of amputation (24% vs. 25%), time (21 vs. 22 months) and type of first relapse (systemic 98% vs. 95%, local 2.3% vs. 4.7%) the site of first metastases (pulmonary, 87% vs. 89%), and good histologic response to preoperative treatment (65% vs. 63%) were essentially the same. The authors concluded that there is no need to employ different therapies for the two groups.

An isolated vertebral metastasis of urachal adenocarcinoma

We describe a case of urachal adenocarcinoma arising in a 30-year-old woman. The patient underwent partial cystectomy. Three years later, she presented with an isolated metastasis to a thoracic vertebra, which was treated by vertebral corporectomy. Histologic findings are described, and the clinical findings, management, and metastatic patterns of this rare tumor, as well as the differential diagnosis on a biopsy specimen, are discussed.

Leiomyosarcoma of the spermatic cord: a light and ultrastructural description of one case

A case of leiomyosarcoma arising in the spermatic cord is described. A 83-year-old man required medical care for an irreducible inguinal hernia. The patient underwent herniorraphy and transinguinal radical orchiectomy. Macroscopically, the spermatic cord was enlarged by a gray-tan and ill-defined neoplasm measuring 4 x 4 x 3 cm. Histologically, this proliferation was composed of atypical spindle cells with blunted end nuclei and eosinophilic cytoplasm. Immunohistochemistry and ultrastructure confirmed the smooth muscle nature of the neoplastic cells. The diagnosis of leiomyosarcoma of the spermatic cord was made. To improve the assignment of this rare lesion to its specific anatomic location, we analyzed the immunohistochemical and ultrastructural characteristics of the smooth muscle tumoral cells and in particular those of the intracellular filament aggregates.

Molecular analysis of p53, MDM2 and H-ras genes in low-grade central osteosarcoma

Low-grade central osteosarcoma is an uncommon form that is characterized by a long premorbid history, and is compatible with prolonged survival after treatment. However, molecular abnormalities are rare in low-grade central osteosarcomas, whereas p53 mutations occur in approximately 20% of conventional high-grade osteosarcomas. In this study, 21 cases of low-grade central osteosarcoma were analyzed for mutations of the p53 gene, amplification of the MDM2 gene, and mutations of the H-ras gene using formalin-fixed, paraffin-embedded materials. We also examined the expression of p53, MDM2, and p21WAF1 protein immunohistochemically and assessed the proliferation activities using the monoclonal antibody MIB-1. One case (4.7%) showed strong p53 immunoreactivity, whereas p53 gene mutations were not detected at all. Seven cases (33.3%) showed immunoreactivity for MDM2 protein. As for gene alterations, MDM2 amplification was found in four cases (19.0%). p21WAF1 expression was detected in 12 cases (57.1%). MIB-1-LI showed very low levels in all the cases and no significant correlation with p53 or MDM2 immuno-reactivity. None of the tumors showed H-ras mutations. In conclusion, the number of p53 gene alterations in low-grade central osteosarcomas is lower than that in conventional high-grade osteosarcomas. MDM2 alterations and p21WAF1 expression might be involved in the tumorigenesis of low-grade central osteosarcomas.

Dedifferentiated parosteal osteosarcoma: The experience of the Rizzoli Institute

BACKGROUND

Dedifferentiated parosteal osteosarcoma (DPOS) is a variant of osteosarcoma in which a high-grade sarcoma coexists with a conventional parosteal osteosarcoma (c-POS), either at presentation (synchronous type) or at the time of recurrence (metachronous type). Only approximately 60 patients have been reported in the literature. The objective of this study was to analyze the clinicopathologic and radiographic features of a relatively large number of patients with DPOS in an attempt to define further the histologic and biologic behavior of this rare entity.

METHODS

In a series of 120 patients with parosteal osteosarcoma who were seen at the Rizzoli Institute from 1958 to 2000, the authors identified 29 patients who were diagnosed with DPOS. The authors reviewed the clinical and radiologic features, histologic sections, treatments, and outcomes in this group of patients with DPOS.

RESULTS

Twelve patients were male, and 17 patients were female. The patients ranged in age from 15 years to 65 yrs (average, 36 years; median, 32 years). One tumor involved the scapula, one involved the ilium, and another involved the skull. All 26 of the other tumors were located in the long bones (14 in the femur, 5 in the humerus, 3 in the tibia, 3 in the fibula, and 1 in the ulna). In 18 patients, radiographic areas of lucency were seen within an otherwise sclerotic lesion. Histologically, the dedifferentiated component was high-grade osteoblastic osteosarcoma in 14 patients, fibroblastic osteosarcoma in 10 patients, giant cell-rich osteosarcoma in 3 patients, and chondroblastic osteosarcoma in 2 patients. All tumors were Stage IIB, and invasion of the medullary canal was detected in 19 patients (65%). Twenty-eight patients underwent surgery, and 18 of those patients received chemotherapy (5 patients received neoadjuvant chemotherapy, and 13 patients received adjuvant). Nine patients were dead and 20 patients were alive (average follow-up, 107 months; range, from 3 months to 36 years) at the last follow-up. Of the nine patients who died, one patient received no treatment, five patients underwent surgery (with three patients achieving adequate margins) in combination with chemotherapy, and three patients underwent surgery only (with adequate margins achieved). Of the 20 patients who remained alive, 13 patients underwent surgery (with 10 patients achieving adequate margins) in combination with chemotherapy, whereas 7 patients underwent surgery only (all with adequate margins). Seven of the nine patients who died had widespread metastases. One patient died of causes unrelated to the tumor, and another patient died shortly after undergoing resection of a lesion in the skull.

CONCLUSIONS

Dedifferentiation occurred in approximately 24% of patients with c-POS. The prognosis for patients with DPOS was better than the prognosis for patients with dedifferentiated central and dedifferentiated peripheral chondrosarcoma.

Desmoplastic fibroblastoma: a light and ultrastructural description of two cases

The authors report 2 cases of collagenous fibroma in which ultrastructural analysis revealed the presence of fibronexus junctions, markers of myofibroblastic differentiation, never described in this rare lesion before. The tumors occurred in the trapezius muscle and in the right arms of a 41 -year-old and a 25-year-old man. They were both intramuscular and showed sharp edges. Grossly, the excised masses were whitish and firm. Microscopically, they were both composed of stellate or spindle-shaped cells separated by a collagenous hypovascular and focally myxoid stroma. Mitotic figures and necrotic areas were not identified. Immunohistochemistry showed positivity for vimentin and focal positivity for smooth and human muscle actin, and flow cytometry showed the tumoral cells to be diploid.

Fibrous dysplasia with degenerative atypia: a benign lesion potentially mistaken for sarcoma

Fibrous dysplasia is a benign disorder of bone in which proliferating fibrous tissue replaces the bony spongiosa. Cytologic atypia is generally not considered a feature of this proliferating tissue. We present a case of fibrous dysplasia with marked atypical nuclear changes consistent with degenerative or regressive changes. A 42-year-old man presented with an osteolytic lesion of the right iliac bone. Histologic study demonstrated a fibro-osseous lesion with woven bone trabeculae and bland-looking fibrous tissue. Several areas showed atypical cells with enlarged pleomorphic nuclei and bizarre features. There was no change in the nuclear-cytoplasmic ratio nor were mitotic figures identified. The differential diagnosis is discussed. When radiographic and other histologic findings suggest fibrous dysplasia, the atypical nuclear changes should not, by themselves, alter the diagnosis.

Simultaneous osteosarcoma lung metastasis and second primary lung cancer

Second malignant neoplasms (SMNs) after treatment of children and adolescent cancers have been extensively studied. Lung cancer as an SMN is rare in all type of primary cancer in children and in osteosarcoma as well. The authors reviewed all cases of osteosarcomas treated at their institution from 1975 to 2000 and found 22 cases of SMN, only 1 involving lung cancer. The authors describe this latter case, a 17-year-old girl with a localized osteosarcoma of the tibia who developed simultaneously lung metastases of osteosarcoma and a primitive lung adenocarcinoma only 18 months from the diagnosis. Lung cancer is unusual in youths as a primary malignancy or as a second primary malignancy. The occurrence of a primitive lung cancer together with lung metastases from osteosarcoma is even more unusual, and examination of all new lung nodules is highly recommended.

Histochemical and ultrastructural study of an elastofibroma dorsi coexisting with a high grade spindle cell sarcoma

Elastofibroma dorsi is a pseudotumoral fibroproliferative lesion characterized by polymorphic fiber-like deposits of elastinophilic material. Several theories have been reported explaining the pathogenesis of elastofibroma. Recent cytogenetic studies have demonstrated chromosomal instability in elastofibromas, not normally observed in non-neoplastic tissues. These chromosomal defects are commonly observed in aggressive fibromatosis too. Such clinical observations suggest a multistage pathogenetic mechanism for the onset of elastofibroma. This study, using histochemical, immunohistochemical staining techniques, and ultrastructural examination, describes the detection of an otherwise typical elastofibroma contextual to a high grade sarcoma. Hence, the coexistence of elastofibroma and high-grade sarcoma may suggest a causal link between the two pathological entities. The results obtained suggest that the coexistence of the two pathological entities is conceivably coincidental.

Osteosarcoma of the pelvis

AIMS

To describe the outcomes of a large number of patients with pelvic osteosarcoma, and to define the guidelines for appropriate treatment.

METHODS

We reviewed 60 consecutive patients with primary pelvic high-grade osteosarcoma. The tumour involved the whole hemipelvis in 15 cases, while the most common location was the iliac wing in 29 cases (48.3%): 25 of these adjacent to or passing the sacroiliac joint.

RESULTS

Thirty patients underwent surgery; there were 16 hindquarter amputations and 14 internal hemipelvectomies. All the patients who presented with metastasis died of their disease. In 18 cases wide margins were achieved, however, eight patients experienced local recurrence. Of the series, only eight patients are still alive.

CONCLUSION

The use of intense chemotherapy and surgical wide margin, hardly seems to achieve local control, however, tumour necrosis was correlated with positive prognosis. When internal hemipelvectomy it is not safe enough, amputation must be considered, particularly for cases with sacrifice of the sciatic nerve roots or for older patients where a shorter surgical procedure can be less risky.