Intimal Sarcoma with MDM2/CDK4 Amplification and p16 Overexpression: A Review of Histological Features in Primary Tumor and Xenograft, with Immunophenotype and Molecular Profiling.

Intimal sarcomas (IS) are rare malignant mesenchymal tumors arising in large blood vessels of the systemic and pulmonary circulation and also in the heart. They are morphologically similar to other spindle cell, poorly differentiated sarcomas. The prognosis is poor and depends mainly on surgical options. Three cases of IS were collected from two institutions. Clinical data were retrieved and histological study was performed. A wide immunohistochemical panel was analyzed. FISH of MDM2 gene was performed, and a molecular study with NGS was implemented in all cases. The mean age of our cases was 54 years. Histologically, the tumors presented a diffuse growth pattern with heterogeneous atypical epithelioid or spindle cells and extensive thrombosed areas. All cases presented intense immunoexpression for MDM2, CDK4, CD117, c-myc, PDGFRA, and p16. PDGFRA, HTERT, and pan-TRK gained expression, while p16 lost intensity, being weaker in both the local recurrences and xenografts. The three cases showed amplification of MDM2 by FISH. NGS analysis revealed amplifications in the CDK4, PDGFRA, and KIT genes, together with BRAF mutation and KRAS amplification. P16 was expressed in all cases, losing intensity in local recurrence and xenografts. Two new alterations, a BRAF mutation and a KRAS amplification, were detected by NGS in different tumors, opening up new therapeutic options for these patients.

Extraskeletal myxoid chondrosarcoma: p53 and Ki-67 offer prognostic value for clinical outcome - an immunohistochemical and molecular analysis of 31 cases.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant soft tissue tumor of unpredictable clinical behavior. The morphological spectrum of EMC based on histology alone can be difficult. There is no precise immunohistochemical (IHC) profile that together with the clinical parameters is able to predict the clinical outcome. We studied 31 cases confirmed as EMC. Clinical and follow-up data were recorded. Histopathological, molecular, and IHC studies were performed. Association among histopathological parameters was assessed using a chi-square test to determine homogeneity or linear trend for ordinal variables. The Kaplan-Meier proportional risk test (log rank) was used to study the impact of the histological, IHC, and molecular factors on progression-free survival (PFS) and disease-specific survival (DSS). Most EMCs showed a typical architectural pattern. Only a few cases presented an atypical histology (higher cellularity and solid pattern). IHC positivity (focal or diffuse) was present for CDK4 (100%), STAT-6 (90%), CD117 (84%), HNK-1 (81%), SATB2 (68%), and S-100 (58%). Synaptophysin and INSM1 were expressed in 22.6% and 38.7% of cases respectively. The EWSR1::NR4A3 rearrangement was found in 19 cases and 7 tumors presented the TAF15::NR4A3 fusion. Positive surgical margins together with atypical histology and expression of p53 and Ki67 correlated with worse clinical prognosis. EMCs express several IHC markers which are also seen in other soft tissue sarcomas. The molecular detection of NR4A3 rearrangement supports the differential diagnosis. Positive surgical margins together with atypical histology and positive expression of p53 and Ki-67 seem to predict a poor clinical outcome with worse prognosis, increased rate of recurrence, metastasis, and poor overall survival.

Comparative assays for the HER-2/neu oncogene status in breast cancer.

CONTEXT: Tumor marker assays, especially those used to indicate the right therapy, should be standardized. OBJECTIVE: To analyze the current methods for the HER-2/neu (h2n) oncogene status by immunohistochemical (IHC) analysis, fluorescence in situ hybridization (FISH), and chromogenic in situ hybridization (CISH) and compare those results with the chromosome 17 copy number and the status of the topoisomerase II alpha (TPIIalpha) gene. DESIGN: We tested 50 infiltrating ductal breast carcinomas (pTNM status varied from pT1 N0 to pT4 N1) using the Food and Drug Administration (FDA)-approved methods HercepTest and Pathway for overexpression of h2n. We also used FISH and CISH to test for h2n amplification and CISH to test for chromosome 17 (c17) and TPIIalpha. The p53 and Ki-67 factors were also evaluated by IHC analysis. RESULTS: h2n overexpression (3+) and amplification were observed in only 6 (12%) of 50 cases by IHC analysis, FISH, and CISH. Three cases that initially scored 3+ and 2+ had 4 to 5.95 signals (equivocal) by FISH but when corrected by the h2n/c17 ratio were nonamplified. TPIIalpha isomerase was amplified in only 2 (4%) of the 50 cases. Nineteen (38%) of the 50 cases were aneuploidic. All h2n amplified cases had high proliferative activity, but only 2 of 6 had p53 protein alterations. CONCLUSIONS: The HercepTest and Pathway IHC assay h2n were fully concordant for the 3+ cases. The 3+ cases had to be confirmed in 75% of the tumor area examined. These 2 IHC assays were fully concordant with FISH and CISH. The 2 in situ hybridization (ISH) assays were 94% concordant for the 50 cases. The cutoff signal points for both ISH assays should be 6 or more. Thus, there is no need for the c17 ratio correction. Tumor heterogeneity appears not be a major problem, but our percentage of amplified cases is lower than previously reported. The FDA-approved IHC and ISH assays should give relatively uniform results when used following our recommendations.