Expression of embryonic lethal abnormal vision (ELAV)-like protein HuR and cyclooxygenase-2 (COX-2) in Ewing sarcoma.

AIMS AND BACKGROUND: HuR is a member of the family of ELAV (embryonic lethal abnormal vision)-like proteins that stabilize several cellular mRNAs by binding to AU-rich elements in the 3' untranslated region of the mRNA. Cyclooxygenase-2 (COX-2) is a well known enzyme that promotes tumor growth and metastasis. Recent studies have shown that HuR can stabilize the mRNA of COX-2, and cytoplasmic expression of HuR is associated with increased COX-2 expression in some cancers. The aim of this study was to investigate the correlation between COX-2 and HuR in Ewing sarcoma. METHODS: The expression patterns for HuR and COX-2 were assessed via immunochemical analysis of 70 Ewing sarcoma samples. RESULTS: Nuclear HuR expression was observed in 12 of 70 (17.1%) cases, but cytoplasmic expression was not observed. COX-2 expression was seen in 25 of 70 (35.7%) samples. Nuclear HuR and COX-2 were simultaneously expressed in 8 of 70 (11.4%) samples. The expression of nuclear HuR was significantly associated with COX-2 expression (P = 0.014). Neither HuR nor COX-2 expression showed a correlation with age or sex. CONCLUSIONS: COX-2 expression in Ewing sarcoma may not be directly related to mRNA stabilization by HuR. However, a correlation between COX-2 expression and nuclear HuR expression through indirect mRNA stabilization can be suggested.

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.

Follow-up study of long-term survivors of osteosarcoma in the prechemotherapy era.

Osteosarcoma is the most common primary bone sarcoma. Several studies published in the 1960s established that approximately one fifth of patients survive when treated with surgery alone. There is no information, however, about the long-term consequences of osteosarcoma. It is especially relevant to know if these patients are at risk for a second malignancy. We reviewed all clinical records from long-term (defined as more than 10 years) osteosarcoma survivors treated at Mayo Clinic in the prechemotherapeutic era from 1900 to 1960. We re-reviewed histological sections for most cases. Patients or next of kin provided follow-up information during telephone interviews. Rates of second malignancy were compared with expected rates in the population at large. We identified 465 patients treated for osteosarcoma. Of these patients, 83 (17.8%) were long-term survivors, including 19 who were alive up to 65 years after treatment. Of the 7 patients with pulmonary metastases, 3 died. A second malignancy developed in 26 patients, 15 of whom died of the malignancy. Although long-term survivors of osteosarcoma have a higher incidence of a second malignant tumor than a normal population, this increase was not statistically significant. No demographic or histological variables predicted long-term survival.

Intraabdominal myositis ossificans: a report of 9 new cases.

Intraabdominal myositis ossificans (IMO) is a rare benign disorder characterized by reactive bone formation in intraabdominal soft tissue that should be distinguished from a malignant condition. We retrospectively searched our patient records and report 9 new cases of IMO. The lesions occurred in 7 men and 2 women with a mean age of 50 years (range, 24--76 years), 5 of whom had previous abdominal surgery. Histologically, all the cases were similar, consisting of a reactive mesenchymal process in adipose tissue. Mitosis was observed, but with no atypical forms, and the lesions lacked malignant cytologic features. IMO is an uncommon benign lesion that develops relatively rapidly. The pathogenesis is related to intraabdominal surgical procedures, but the exact mechanism remains to be determined.

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.

Expression of collagen type II, S100B, S100A2 and osteocalcin in chondroblastoma and chondromyxoid fibroma.

Chondroblastoma and chondromyxoid fibroma (CMF) has been investigated in numerous histological studies, but its biological nature and histogenetic origin are still a matter of debate. We evaluated the expression of type II collagen, S100A2, S100B, and osteocalcin to study the matrix biochemistry and phenotype of the neoplastic cells in these tumors. Immunohistochemically, the expression of type II collagen was diffuse in 15 cases (75%) among total 20 chondroblastomas and 12 (85.7%) among total 14 CMFs. The expression of S100B was also diffuse in all cases (100%) of chondroblastomas and 12 cases (85.7%) of CMFs. We were able to obtain the expression of S100A2, focally. The expression of osteocalcin was focally noted in 18 cases (90%) of chondroblastomas and 8 cases (57.1%) of CMFs. In conclusion, our data support that chondroblastoma and CMF are a distinct tumor entity with the basic expression of chondroid markers. But these tumors also show histologic diversity with focal co-expression of osteoid markers.

Inactivation of the RASSF1A in osteosarcoma.

We investigated the expression and mutation of three isoforms of the Ras effector RASSF1 in 10 primary osteosarcomas and 6 osteosarcoma cell lines. RASSF1A was not expressed in 40% (4/10) of the primary osteosarcomas and 83.3% (5/6) of the osteosarcoma cell lines. RASSF1B and RASSF1C expression was absent in 30% (3/10) and 0% (0/10) of primary tumors, and 100% (6/6) and 0% (0/6) of osteosarcoma cell lines, respectively. Treatment of these cell lines with the DNA methylation inhibitor 5-aza-2'-deoxycytidine reactivated the transcription of RASSF1A, but not that of RASSF1B or RASSF1C. No somatic mutations were noted in RASSF1 in either the primary tumors or cell lines. Our data indicate that epigenetic inactivation of RASSF1A by hypermethylation of its promoter region is a frequent event, and may play an important role in the tumorigenesis of osteosarcomas.

Lack of Bcl10 mutations in malignant cartilaginous tumors.

The Bcl10 gene was recently isolated from the breakpoint region of t(1;14)(p22;q32) in mucosa-associated lymphoid tissue (MALT) lymphomas. Somatic mutations of Bcl10 were found in not only t(1;14)-bearing MALT lymphomas, but also a wide range of other tumors. To clarify the actual frequency and spectrum of Bcl10 mutations in primary malignant chondrogenic tumors, we examined 89 cases of malignant chondrogenic tumors comprising 17 conventional chondrosarcomas, 33 mesenchymal chondrosarcomas, and 39 clear cell chondrosarcomas. Polymerase chain reaction single-stranded conformation polymorphism and sequencing analyses were done. No Bcl10 mutations were found in our series of malignant chondrogenic tumors. While screening for mutations, we also found three polymorphisms at codons 8 exon 1 of the Bcl10 gene. Our results strongly suggest that somatic mutations of Bcl10 are extremely rare in malignant cartilaginous tumors and do not commonly contribute to their molecular pathogenesis.

Radiographic, CT, and MR imaging features of dedifferentiated chondrosarcomas: a retrospective review of 174 de novo cases.

Up to 11% of chondrosarcomas may undergo regional anaplastic change, resulting in a high-grade noncartilaginous sarcoma arising within a typically low-grade chondrosarcoma. Known as dedifferentiated chondrosarcomas, these tumors are highly malignant with a very poor prognosis. The most important factor affecting survival is an accurate preoperative diagnosis. Therefore, the ability to predict the possibility of dedifferentiation in a malignant cartilage tumor on the basis of imaging findings is critical to ensure adequate tumor sampling at the time of biopsy. Imaging findings at radiography, computed tomography (CT), and magnetic resonance (MR) imaging in 174 patients with dedifferentiated chondrosarcoma were reviewed to determine whether there are radiologic features that can help predict dedifferentiation. On approximately one-third of the radiographs, one-third of the MR images, and one-half of the CT scans, the tumors demonstrated bimorphic features (ie, distinctly different tumor features juxtaposed within the lesion), most frequently a dominant lytic area adjacent to a mineralized tumor at radiography and a large, unmineralized soft-tissue mass associated with an intraosseous chondroid-containing tumor at CT and MR imaging. In the initial evaluation of patients with a primary bone tumor, thorough evaluation of the radiologic features of the entire tumor is critical.

Absence of amplification of HER-2/neu (c-erbB-2) gene in Ewing's sarcoma: a real-time polymerase chain reaction method.

Amplification and overexpression of the HER-2/neu (c-erbB-2) oncogene have been observed in many cancers and are associated with a poor prognosis particularly in breast cancer. The human epidermal growth factor (HER)-2 receptor has recently been implicated in Ewing's sarcoma tumor cell line growth and chemosensitivity. The present study evaluates the amplification of HER-2/neu gene in paraffin sections from 42 cases of Ewing's sarcoma by a real-time quantitative polymerase reaction method using LightCycler system (Roche diagnostics, GmbH Mannheim, Germany). The relative copy number of HER-2/neu versus beta-globin was calculated at the crossing point. The mean calculated copy number in these cases of Ewing's sarcoma and normal controls was 26.43 and 26.93, respectively. The p value was 0.215 (p<0.05). Our results demonstrated an absence of HER-2/neu oncogene amplification in Ewing's sarcomas, and we suggest that HER-2/neu is not a biologically or therapeutically important pathway in Ewing's sarcoma.

Chordoma. Cytomorphologic findings in 14 cases diagnosed by fine needle aspiration.

OBJECTIVE: To review the clinical and cytomorphologic features of 14 chordomas diagnosed by fine needle aspiration biopsy (FNAB) at our institution. STUDY DESIGN: The cytology files from January 1985 to February 2000 at Mayo Clinic, Rochester, Minnesota, U.S.A., were searched for all cases diagnosed as chordoma by FNAB. Clinical, radiographic and cytomorphologic findings of each case were reviewed. RESULTS: Ten males and four females (mean age, 55 years; range, 14-78) had tumors involving the sacrum (8), clivus (3) and vertebrae (lumbar, 2; cervical, 1). Pain was the presenting symptom in 11 patients. Most smears (82%) were cellular with a fibrillary background. Chondroid matrix was recognized in nine cases. Small, epitheliallike cells constituted the predominant cellular component in nine cases. Cells with clear, vacuolated cytoplasm were seen in almost 'every case; however, true physaliferous cells were rare. Mitotic figures were seen in four cases, binucleation in six and multinucleated giant cells in seven. Needle biopsies contained diagnostic material in all cases. Of the nine patients with follow-up (mean, 57 months; range, 3-184 months), three patients were alive and free of disease, five were alive with disease, and one was dead of disease at this writing. CONCLUSION: Because various cytologic presentations and overlapping cytologic features occur between chordoma, chondrosarcoma and metastatic clear cell carcinoma, it is important to recognize the various appearances of chordoma in FNAB.

Clinicopathologic features, diagnosis, and treatment of fibrosarcoma of bone.

Fibrosarcoma of bone is a relatively rare tumor; it accounts for less than 5% of bone sarcomas. The anatomical sites most commonly involved are the metaphyses of long tubular bones. Local pain, swelling, limitation of motion, and pathologic fracture are the common clinical signs and symptoms. Typical imaging findings include eccentrically located lytic lesions, with a geographic, moth-eaten, or permeative pattern of bone destruction, and extension into adjacent soft tissues. Surgery is the treatment of choice. The type of surgical procedure depends mainly on histologic grade, local conditions, and tumor location. With a high probability of metastases (>70%) after surgical treatment, perioperative adjuvant treatment modalities should be considered for high-grade tumors. The most important prognostic factors affecting survival include tumor grade, patient's age, and tumor location.

Multicentric osteosarcoma: clinicopathologic and radiographic study of 56 cases.

Multicentric osteosarcoma (M-OGS) is characterized by multicentricity of osseous osteosarcomas, either synchronous or metachronous, without visceral involvement. The study's purpose was to clinicopathologically and radiographically analyze 56 cases of M-OGS (22 synchronous and 34 metachronous). The distal femur was the most common site. Histologically, all tumors were high grade. Of 22 patients with synchronous M-OGS, 16 had 3 or more simultaneous tumors; the axial skeleton was involved in 14 (64%) of 22 cases. In metachronous M-OGS, the second malignancy occurred after a median of 22 months. Treatment was surgery, chemotherapy, radiotherapy, or a combination of these. Patients with metachronous osteosarcoma had a median survival longer than did patients with synchronous tumors. Overall, 8 long-term survivors were treated by aggressive surgery with wide margins (plus chemotherapy and/or radiotherapy). M-OGS combines multiple skeletal locations of high-grade conventional osteosarcomas and has a poor prognosis. Aggressive surgery may result in improved long-term survival, particularly in patients with metachronous disease.

Primary Rosai-Dorfman disease of bone: a clinicopathologic study of 15 cases.

Sinus histiocytosis with massive lymphadenopathy or Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder of unknown etiology. Most patients present with lymph node involvement manifesting as adenopathy; however, RDD may arise primarily in a variety of extranodal sites, including bone. We report herein our experience with 15 cases of primary intraosseous RDD. The patients include 8 females and 7 males, who ranged in age from 3 to 56 (mean 27) years. The lesions arose in a variety of anatomical locations, including the tibia, femur, clavicle, skull, maxilla, calcaneus, phalanx, metacarpal, and sacrum. Radiographically, the lesions were lytic with well defined and usually sclerotic margins. Histologically, the lesions demonstrated the classic features of RDD and consisted of a mixed inflammatory infiltrate with numerous large histiocytes with abundant eosinophilic cytoplasm which exhibited emperipolesis. Some cases also contained numerous neutrophils. Immunohistochemical stains showed that the large histiocytes were S-100 positive. Follow-up information was available for 12 patients. Five patients eventually developed additional extraosseous manifestations, including testicular, lymph node, and subcutaneous lesions. One of these 5 also developed a new bony lesion within the sternum. One patient developed additional lesions within multiple bones of the hand and wrist, without extraosseous disease. One patient had stable bony lesions, whereas 5 remained disease free after treatment.

Incidence, prevalence, and management of intraductal papillary mucinous neoplasm in Olmsted County, Minnesota, 1984-2005: a population study.

OBJECTIVES: Intraductal mucinous papillary neoplasm (IPMN) is being recognized with increasing frequency around the world. The true incidence, however, remains unknown. Our goal was to determine the incidence of IPMN in a population study. METHODS: We used the records-linkage system of the Rochester Epidemiology Project to ascertain age- and sex-adjusted incidence rates of IPMN in Olmsted County, Minn, from January 1, 1984, to December 31, 2005. We also evaluated the number of prevalent cases as of December 31, 2005. RESULTS: We identified 28 incident cases of IPMN. The age- and sex-adjusted cumulative incidence for IPMN in Olmsted County is 2.04 cases per 100,000 persons (95% confidence interval [CI], 1.28-2.80) from 1984 to 2005. Point prevalence on December 31, 2005, was 25.96 cases per 100,000 persons (95% CI, 14.53-37.38 cases) or 1 per 3852. Restricting to county residents 60 years and older, the point prevalence is 99.10 cases per 100,000 persons (95% CI, 54.40-143.79 cases) or one per 1009 persons. Thirty-two percent of patients were treated surgically. The 5-year survival rate after diagnosis was 59.6%. CONCLUSIONS: The incidence of IPMN in Olmsted County is low but increasing. Most patients do not die of complications related to the disease.

Frequency of USP6 rearrangements in myositis ossificans, brown tumor, and cherubism: molecular cytogenetic evidence that a subset of "myositis ossificans-like lesions" are the early phases in the formation of soft-tissue aneurysmal bone cyst.

OBJECTIVE: USP6 rearrangements with several partner genes have been identified recently in primary but not in secondary aneurysmal bone cysts (ABCs). Several lesions show histologic features that may overlap with ABC, including myositis ossificans (MO), brown tumor, and cherubism. The objective of this study was to assess whether these lesions harbored USP6 rearrangements. MATERIALS AND METHODS: Twelve patients with classic radiologic and histologic features of MO, 6 with brown tumors, and 5 with cherubism diagnosed at our institution were studied for the presence of USP6 rearrangements using fluorescence in situ hybridization with probes flanking the USP6 locus on chromosome 17p13. In addition, conventional cytogenetic analysis was performed in 2 patients with cherubism. RESULTS: USP6 rearrangements were identified in 2 patients with radiologic and histologic features consistent with MO. None of the patients with brown tumor or cherubism demonstrated USP6 rearrangements. Cytogenetic analysis of the cherubism patients demonstrated normal karyotypes. CONCLUSION: These findings indicate that a subset of cases with apparent classic histologic and imaging features of MO are rather better classified as being soft-tissue ABC with clonal USP6 rearrangements. In contrast, no USP6 rearrangements were found in patients with cherubism or brown tumor, supporting the prevailing view that these lesions are distinct biologic entities.

Intraoperative diagnosis of isolated cardiac sarcoid.

Cardiac sarcoid is a rare and frequently fatal disease. We report a case of isolated cardiac sarcoid diagnosed during elective cardiac surgery. Although this patient presented with a history that was consistent with sarcoid heart disease, diagnosis is challenging when there is no other organ involvement with sarcoid. The patient was successfully treated with steroids and 8 years later remains clinically free of sarcoidosis.

Ameloblastic carcinoma: an analysis of 14 cases.

OBJECTIVES: To present the classifications of malignant ameloblastomas, provide histopathologic guidelines for the diagnosis of ameloblastic carcinoma, and discuss treatment and long-term follow-up. STUDY DESIGN: Fourteen archival specimens of ameloblastic carcinoma with detailed treatment and follow-up documentation were identified by the authors. RESULTS: Traditional methods of microscopic observation form the basis for diagnosis. Histopathologic features of ameloblastic carcinoma include lack of differentiation, hypercellularity, high mitotic index, vascular invasion, and neural invasion. CONCLUSION: The long-term follow-up findings in this study support the concept that aggressive surgical intervention provides the best chance for survival. Patients treated otherwise had recurrence. The patients with the highest number of recurrences did not survive the disease.

Periosteal osteoblastoma: report of a case with a rare histopathologic presentation and review of the literature.

Osteoblastoma is an uncommon benign bone tumor most commonly located in the vertebral column or metaphysis of a long bone. Periosteal location is rare. We report a periosteal-based osteoblastoma, arising from the proximal tibia, in a 20-year-old woman who presented with knee swelling and pain of 2-year duration. Imaging studies showed a metaphyseal surface-based lesion with patchy radiodensities. The cortico-medullary junction was intact. The lesion was totally excised. Histopathologic evaluation disclosed immature bone and osteoid deposition in a vascularized stroma, associated with numerous osteoblasts and osteoclasts rimming the bony trabeculae. Plate-like arrangements of cartilage in the margin of the neoplastic tissue were also identified. At 16 months postoperatively, the patient was well without recurrence. Although extremely unusual, the presence of cartilage does not necessarily exclude the diagnosis of osteoblastoma.