TBX2 is preferentially amplified in BRCA1- and BRCA2-related breast tumors.

The chromosome 17q23 region is frequently amplified in breast tumors. Gain of the region is present in 50% of BRCA1-associated breast tumors and 87% of BRCA2-associated breast tumors. The amplification frequency of the RPS6KB1 and TBX2 oncogenes from this amplicon was compared in 27 BRCA1 and BRCA2 mutant breast tumors, 15 breast tumors from high-risk patients with no BRCA1 or BRCA2 mutations, and 62 matched sporadic breast tumor controls. TBX2 was determined to be preferentially amplified and overexpressed in BRCA1 and BRCA2 mutant tumors, whereas RPS6KB1 was not, suggesting a role for TBX2 amplification in the development of BRCA1- and BRCA2-associated breast tumors.

Pericardial ectopic thymoma.

Primary intrapericardial thymoma is an unusual localization. We report a case of a patient with an isolated and primary pericardial thymoma. This 72-year-old woman presented with dyspnea, dysphony and myalgia. The radiological evaluation revealed an intrapericardial mass. Surgical exploration showed a hemorrhagic and infiltrative tumor in the pericardial sac, while the mediastinum was free of tumor. Surgical biopsies and, later, an ablation of pericardial mass were done. The tumor was a thymoma, composed of large epithelial cells and immature T lymphocytes and was classified B2 according to the World Health Organization classification (1999). Clinically, a myasthenia gravis was revealed. We discuss the few cases reported in the literature.

[Buerger's disease or thromboangiitis obliterans revealed by an enteric ischemia. Case report and literature review]. / La maladie de Buerger ou thromboangéite oblitérante révélée par un infarctus mésentérique.

Thromboangiitis obliterans or Buerger's disease is a rare arteritis affecting mainly young male smokers. Distal limb symptoms are well-known. Digestive manifestations, especially when inaugural, are less known and sometimes misdiagnosed. We report the case of a 37-year-old man who developed a large mesenteric infarct with diffuse ischemic colitis and ischemia in the hepatic artery field. Histopathological findings were consistent with thromboangiitis obliterans. Unexplained abdominal pain, even if inaugural, in young male smokers, should evoke the possibility of Buerger's disease.

Recurrent and non-recurrent pigmented villonodular synovitis 1.

Pigmented villonodular synovitis (PVNS) is a benign intra-articular lesion. Patients are at risk for local recurrence. Factors that predict recurrence are not established. Two groups of patients were retrieved from our files. One consisted of 25 patients who had one or more recurrences within 5 years after primary surgery. The second group contained 18 historical controls free of recurrence for at least 5 years after primary surgery. Patient medical records and surgical notes were reviewed. We compared proliferative activity and DNA ploidy using digital image analysis, and other clinicopathologic features between the 2 groups of patients. The location of PVNS was significantly different between the two groups (p=0.03). In the recurrence group, there were 7 (28%) cases with disease in the knee. However, none of the controls had disease in the knee. Among recurrent cases, tumors in the knee were, on average, larger than tumors in the small joints. The size of all recurrent tumors was not significantly different than non-recurrent tumors (median of 1.8 cm versus 1.3 cm, respectively; p=0.06). There were no significant differences in age, sex, completeness of surgical removal, MIB-I index, DNA ploidy, or the percent of tumor nuclei in the diploid, S-phase, tetraploid, or hypertetraploid DNA histogram categories between the two groups. Our results indicate that recurrent PVNS tumors were more likely to be located in the knee, which may be related to larger tumor size. Patient age, sex, completeness of surgical removal, DNA ploidy, and MIB-I proliferation were not significantly different between recurrent and non-recurrent lesions.

Skin metastases from unknown origin: role of immunohistochemistry in the evaluation of cutaneous metastases of carcinoma of unknown origin.

Determining the primary origin of skin metastases might be a challenging issue for pathologists, especially when there is no primary history or when this history is unavailable. The poor specificity of morphological appreciation is challenging, emphasizing the need for ancillary studies. We have retrieved 44 cases of skin metastases from our pathology files. Paraffin blocks were collected and homemade tissue arrays were made. We have tried to assess the primary origin based on morphological data alone, and then using 13 antibodies (cytokeratins (CK) 5/6, 7, 19, 20, thyroid transcription factor-1, carcinoembryonic antigen, PS100, tumor-associated glycoprotein 72, BerEP4, estrogen receptor (ER), progesterone receptor (PR), CD10, and E-cadherin). Most metastases in our series were from breast (13) and colorectal cancers (six) as they are the main clinical activity in our hospital. Only 44% of cases were correctly assessed based on the sole morphology, emphasizing the need for ancillary studies. CK 20, ER, and PR were the most helpful markers to determine the primary origin of skin metastases by highlighting colorectal origin and mammary origin, respectively. By far, clinical information and morphological evaluation are more reliable than the use of ancillary techniques, which have to be used in the absence of the former one and the poor differentiation of the latter ones. Azoulay S, Adem C, Le Pelletier F, Barete S, Francès C, Capron F. Skin metastases from unknown origin: role of immunohistochemistry in the evaluation of cutaneous metastases of carcinoma of unknown origin.

Microsatellite instability in hereditary and sporadic breast cancers.

Sporadic cancers and familial breast cancers are characterized by an increase in genetic instability. Little is known about whether mismatch repair defects accompany this genetic instability. We investigated invasive and/or in situ breast cancers from 30 women with deleterious BRCA1/2 mutations and unclassified variant BRCA1/2 alterations. Forty cases of sporadic breast cancers were also investigated, including 7 medullary carcinomas. Malignant and benign lesions were examined from all cases to better understand tumor progression. Automated immunohistochemistry, with antibodies directed against hMLH1 and hMSH2, was used to screen cases for possible mismatch repair defects. When loss of expression was noted, DNA ploidy was performed by cytomorphometry. DNA, after laser microdissection, was extracted from a majority of familial cases and their corresponding controls, and microsatellite instability analysis was performed. None of the familial or sporadic cases had loss of hMSH2 expression. All but one lesion, a DCIS arising in a deleterious BRCA2 mutation carrier, had loss of hMLH1 expression and a tetraploid profile by image cytomorphometry. There was no MSI in any explored lesions (n = 34), as determined by molecular analysis, including the DCIS with loss of hMLH1 expression. We conclude that DNA mismatch repair defects involving hMLH1 and hMSH2 underexpression are extremely rare events in sporadic and familial breast cancer. Mismatch repair gene mutations may be secondary random events in breast cancer progression.

ERBB2, TBX2, RPS6KB1, and MYC alterations in breast tissues of BRCA1 and BRCA2 mutation carriers.

Breast cancer risk is greatly increased in women who carry mutations in the BRCA1 or BRCA2 genes. Because breast cancer initiation is different between BRCA1/2 mutation carriers and women who do not carry mutations, it is possible that the mechanism of breast cancer progression is also different. Histopathologic and genetic studies have supported this hypothesis. To test this hypothesis further, we utilized a large cohort of women who underwent therapeutic mastectomy (TM) and contralateral prophylactic mastectomy (PM). From this cohort, we developed case groups of women with a family history of breast cancer with BRCA1/2 deleterious mutations, with unclassified variant alterations, and with no detected mutation and matched these cases with sporadic controls from the same TM and PM cohort. Fluorescence in situ hybridization was performed on paraffin sections by use of dual-color probes for ERBB2/CEP17, MYC/CEP8, TBX2/CEP17, and RPS6KB1/CEP17. All malignant and benign lesions, including putative precursor lesions, were studied. The invasive cancers from deleterious mutation carriers had a higher prevalence of duplication of MYC (P = 0.006) and TBX2 (P = 0.0008) compared to controls and a lower prevalence of ERBB2 amplification (P = 0.011). Coduplication of MYC and TBX2 was common in the in situ and invasive lesions from the deleterious mutation carriers. The odds ratio of having a BRCA1/2 mutation is 31.4 (95% CI = 1.7-569) when MYC and TBX2 are coduplicated but ERBB2 is normal. Unclassified variant carriers/no mutation detected and sporadic controls had a similar prevalence of alterations, suggesting that hereditary patients with no deleterious mutations follow a progression pathway similar to that of sporadic cases. With the exception of one atypical ductal hyperplasia lesion, no putative precursor lesion showed any detectable alteration of the probes tested. There was no significant intratumoral heterogeneity of genetic alterations. Our data confirm that a specific pattern of genomic instability characterizes BRCA1/2-related cancers and that this pattern has implications for the biology of these cancers. Moreover, our current and previous results emphasize the interaction between phenotype and genotype in BRCA1/2-related breast cancers and that a combination of morphologic features and alterations of ERBB2, MYC, and TBX2 may better define mechanisms of tumor progression, as well as determine which patients are more likely to carry BRCA1/2 mutations.

Pathologic characteristics of breast parenchyma in patients with hereditary breast carcinoma, including BRCA1 and BRCA2 mutation carriers.

BACKGROUND: BRCA1 and BRCA2 alterations are associated with an increased risk of developing breast carcinoma. The authors hypothesized that the progression of breast neoplasia may differ between patients with hereditary disease and patients with nonhereditary disease and that this difference in progression may be visualized by studying the prevalence of precursor lesions and neoplastic lesions. METHODS: The authors developed two case cohorts of high-risk patients with a strong family history of breast carcinoma who underwent prophylactic mastectomy. The first cohort was comprised of women who underwent therapeutic mastectomy and contralateral prophylactic mastectomy, and the second cohort was comprised of women who underwent bilateral prophylactic mastectomy. Patients without a family history of breast carcinoma who underwent unilateral or bilateral prophylactic mastectomy were selected as a control group. DNA from peripheral blood leukocytes was screened for BRCA1 and BRCA2 mutations. The available pathologic materials were reviewed independently by two pathologists, and all neoplastic and precursor lesions were identified and classified. Proliferation activity was assessed using MIB-1 immunohistochemistry on all available lesions from the unilateral mastectomy cohort. RESULTS: The 28 women from the unilateral cohort with deleterious BRCA1/2 mutations had a lower prevalence of proliferative fibrocystic changes (PFC) (7%) compared with their matched control group (25%) (P = 0.075) and with patients who had a family history but no BRCA1/2 mutation (22-33%). None of the 11 deleterious mutation carriers from the bilateral cohort (0%) had PFC compared with 36% of women in the matched control group (P = 0.03). There was no major difference in the prevalence of other precursor lesions (including in situ carcinoma) in either cohort. Invasive carcinomas from the deleterious mutation carriers in the unilateral cohort were of higher grade compared with the control group (P = 0.003) and patients without a mutation (P < 0.0001) but were of similar grade compared with carriers of unclassified variant BRCA1/2 alterations (P = 0.20). Neoplastic lesions from the deleterious mutation carriers in the unilateral cohort had higher MIB-1 proliferation indices compared with other patients with and without a family history of breast carcinoma. CONCLUSIONS: The current data suggest that the progression rate of breast neoplasia is accelerated in women who carry BRCA1/2 deleterious mutations compared with other patients who have breast carcinoma with or without a family history. This increased progression rate should be taken into account when considering the surveillance of asymptomatic women.