Aggressive osteoblastoma: a case report involving a unique chromosomal aberration.

Osteoblastomas are rare bone-producing neoplasms that generally occur in the young and can be misdiagnosed as an osteosarcoma if correlation with clinical history, radiology, and histology is not carefully considered or if the several variants of osteoblastoma are not recognized. These variants lie on a morphologic spectrum between conventional osteoblastoma and osteosarcoma. Aggressive osteoblastoma is one such subtype. As the name implies, the histologic features of aggressive osteoblastoma may appear malignant, and its biologic behavior may separate it from conventional osteoblastoma. We report a case of aggressive osteoblastoma occurring in the femoral diaphysis of a 12-year-old girl; this osetoblastoma was dyssynchronous from the radiologic appearance and a diagnostic challenge. Cytogenetic evaluation of the neoplasm revealed a pseudodiploid clone with a balanced translocation involving chromosomes 4, 7, and 14. Using the premise that cytogenetics might be useful as a diagnostic tool for a more specific classification, we reviewed the literature in order to compare our findings with known chromosomal aberrations.

Using a higher cutoff for the percentage of HER2+ cells decreases interobserver variability in the interpretation of HER2 immunohistochemical analysis.

The effect of using a 30% cutoff for the proportion of HER2+ cells on the interobserver variability in the interpretation of HER2 immunohistochemical results was evaluated. Immunostained sections from 96 cases of breast carcinoma were reviewed by 10 pathologists and scored as positive (3+) when uniform strong membranous staining was identified in at least 10% of tumor cells; the actual percentage of cells with such staining was also estimated. The agreement rates and the kappa values using a 30% cutoff were compared with those using a 10% cutoff. These proved to be higher in 62% and 66% of measurements, respectively, with average interobserver rates and kappa values of 72% and 0.54 using the 30% cutoff and 70% and 0.49 using the 10% cutoff (P=.001 for all comparisons). Using a 30% cutoff for the percentage of HER2+ cells by immunohistochemical analysis modestly decreased interobserver variability in the interpretation of HER2 immunohistochemical results.

Expression of c-kit and platelet-derived growth factor receptors in ovarian granulosa cell tumors.

OBJECTIVE: This study aimed at evaluating the expression of tyrosine kinase receptors c-kit, (platelet-derived growth factor receptor-alpha (PDGFR-alpha), and PDGFR-beta in ovarian granulosa cell tumors (GCTs). STUDY DESIGN: Primary ovarian GCT specimens were obtained for immunohistochemical staining.The expressions of c-kit, PDGFR-alpha, and PDGFR-beta were analyzed and scored by a semiquantitative (SQ) method. Normal ovarian tissue from the same patients' specimens served as internal controls. RESULTS: A total of 21 specimens were available for evaluation. C-kit was expressed in only 2 samples, whereas both PDGFR-alpha and PDGFR-beta stained positive in 100% of tumors. PDGFR targets demonstrated strong positive expression in intensity and amount of tissue stained. Normal ovarian tissue demonstrated complete absence of staining for all 3 antibodies evaluated. CONCLUSIONS: The data demonstrated significant expression of PDGFR targets of imatinib mesylate in GCTs, whereas normal ovarian tissues had a complete absence of staining.This expression profile provides the rationale to investigate the role of imatinib mesylate in PDGFR-positive GCTs.

Juxtacortical chondromyxoid fibroma of bone: a unique variant: a case study of 20 patients.

BACKGROUND: Chondromyxoid fibroma (CMF) is a rare neoplasm of the appendicular skeleton of young adults. We report 20 cases of a poorly recognized subtype which arises on the surface of long bones and erodes the cortical surface causing a periosteal reaction. This entity should be included in the differential diagnosis of bone surface lesions as it may be mistaken for a more aggressive neoplasm. DESIGN: A retrospective review at the Mayo Clinic identified 259 CMF cases, 13 of which were parosteal. Additionally, 2 cases were diagnosed at the University of Alabama at Birmingham and 5 cases were from one of our authors' files. We reviewed the clinical radiographic and pathologic findings of all 20 cases. RESULTS: Juxtacortical CMF occurred over a large age range (12 to 82 y) with a median age of 40.2 years. A slight male predilection (5:4) was seen. The most common presentation was bone pain. All 20 cases showed solitary, radiolucent surface lesions with sclerotic margins and extension into the overlying soft tissues. Most of the lesions were in the proximal tibial metaphysis. Histologically, the tumors had characteristic features of CMF. Several cases contained distinctive areas of calcification, which is not a feature of conventional CMF. Eleven of 12 cases were cured with simple excision. CONCLUSION: CMF should be included in the differential diagnosis of bone surface lesions. The clinical and radiologic findings must be known. The morphology of this lesion is similar to conventional CMF with the exception of focal exuberant calcification. Conservative therapy is the treatment of choice.

Mucinous expression in benign and neoplastic glandular lesions of the uterine cervix.

CONTEXT: Mucins are glycoproteins produced by both normal and neoplastic glandular epithelial cells including endocervix. OBJECTIVE: To determine the expression of mucins in uterine cervical glandular lesions and whether mucin expression correlates with the nature and origin of the glandular lesions. DESIGN: Antibodies to MUC1, MUC2, MUC4, and MUC5AC were applied on 52 cases including 14 endocervical adenocarcinomas (including 4 adenosquamous carcinomas), 9 endometrial carcinomas (8 endometrioid adenocarcinomas and 1 adenosquamous carcinoma), 8 adenocarcinoma in situ (AIS), 2 glandular dysplasias, 6 tubal metaplasias, 10 microglandular hyperplasias, and 3 normal endocervix. The presence of any staining was considered positive. RESULTS: All benign endocervical epithelia, including tubal metaplasia and microglandular hyperplasia, expressed MUC1, MUC4, and MUC5AC but not MUC2. Almost all endocervical AIS and carcinomas and all endometrial adenocarcinomas expressed MUC1; the exceptions were 2 cases of endocervical adenocarcinoma and 1 case of adenosquamous carcinoma of the endocervix. MUC2 staining was noted in 25%, 40%, and 22% of AIS, endocervical adenocarcinomas, and endometrial adenocarcinomas, respectively. About 38% of AIS, 75% of endocervical adenocarcinomas, and 44% of endometrial adenocarcinomas expressed MUC4. Half of AIS, most of endocervical adenocarcinomas, and 22% of endometrial adenocarcinomas expressed MUC5AC. The difference in MUC4 and MUC5AC expression between benign endocervical lesions and AIS and the difference in MUC5AC expression between endocervical and endometrial neoplasms were statistically significant. CONCLUSIONS: Mucin expressions differed among benign endocervical lesions and AIS and among endocervical and endometrial malignancies. These results suggest that mucin staining may potentially be helpful in differentiating various uterine cervical glandular lesions.