Theodore H. Niemann

Epigenetic PTEN silencing in malignant melanomas without PTEN mutation.

A tumor suppressor gene at 10q 23.3, designated PTEN, encoding a dual specificity phosphatase with lipid and protein phosphatase activity, has been shown to play an important role in the pathogenesis of a variety of human cancers. Germline mutations in PTEN cause Cowden syndrome (CS), which is characterized by multiple hamartomas and a high risk of breast and thyroid cancers. Frequent loss of heterozygosity at 10q is found in both early and advanced-stage sporadic melanomas; however, mutations or deletions in PTEN are detected mainly in melanoma cell lines. In this study, we examined PTEN expression in 34 unselected sporadic melanomas (4 primary melanomas, 30 metastases) using immunohistochemistry and correlated this with the results of structural studies of this gene. Immunostaining of 34 melanoma samples revealed no PTEN expression in 5 (15%) and low PTEN expression in 17 (50%), whereas the rest of the tumors (35%) had high levels of expression. Hemizygous deletion was found in 32% of the tumors but neither intragenic PTEN mutation nor biallelic deletion was found in any of the samples. Of the 5 melanomas showing no PTEN expression, 4 had no mutation or deletion of PTEN. Of the 13 tumors having weak PTEN immunoreactivity and informative loss of heterozygosity results, 6 had evidence of hemizygous allelic loss of PTEN while the remaining 7 had intact PTEN. These results strongly support PTEN as a major tumor suppressor on 10q involved in melanoma tumorigenesis and suggest an epigenetic mechanism of biallelic functional inactivation not previously observed in other cancers where PTEN might be involved.

HER-2/neu amplification and overexpression in endometrial carcinoma

HER-2/neu is a proto-oncogene associated with poor prognosis in women with breast and ovarian carcinoma. The significance of HER-2/neu in endometrial carcinoma is less clearly established. The authors compared HER-2/neu gene amplification using fluorescence in situ hybridization and protein overexpression using immunohistochemistry with survival in patients with endometrial carcinoma. Fluorescence in situ hybridization and immunohistochemical staining were performed on 72 formalin-fixed, paraffin-embedded endometrial carcinoma specimens. Vysis combination HER-2/neu and centromere 17 probe mixture was applied to isolated tumor cell nuclei. A minimum of 200 nuclei were scored for each specimen using standard signal enumeration criteria. A specimen was considered amplified with 5% or greater amplified nuclei. Tissue sections were immunostained with polyclonal antibody against p185erb-2 transmembrane glycoprotein. Immunohistochemical reactivity was scored on a three-tiered scale. HER-2/neu gene amplification and protein overexpression were detected in 15 of 72 (21%) and 12 of 72 (17%) of the specimens, respectively, with 2 cases of normal copy overexpression and 5 cases of amplification without overexpression. Both amplification and overexpression were associated with higher grade tumors. Amplification was associated with clear cell and serous subtypes (p = 0.002), and overexpression with only clear cell type (p = 0.006). Using the proportional hazards model of survival, amplification was found to have significant negative predictive value beyond stage, grade, and cell type (p = 0.002). HER-2/neu gene amplification as detected by fluorescence in situ hybridization in archival material has significant prognostic value.

The value of second opinion in gastrointestinal and liver pathology.

OBJECTIVE The value of routine second opinion review of liver and gastrointestinal pathologic material was evaluated to determine whether there were discrepancies in diagnoses and if these discrepancies had an impact on treatment or prognosis. MATERIALS AND METHODS All gastrointestinal and hepatobiliary histopathology referral diagnoses made during a 1-year period for patients being treated at Ohio State University Medical Center were compared with the outside pathologic diagnosis. All major discrepant diagnoses were reviewed by at least 2 pathologists. Diagnoses were classified as no diagnostic disagreement, diagnostic disagreement, or no diagnostic disagreement but pertinent information missing or terminology unclear. Discrepant cases were also classified according to the clinical significance of the discrepancy. RESULTS Pathology reports from 194 hepatobiliary and gastrointestinal cases were reviewed. Of the hepatobiliary cases, 57 (64.8%) of 88 cases showed no discrepancies. Discrepancies were noted in 31 cases (35.2%), including missing information or unclear terminology in the diagnosis in 23 cases (26.1%) and diagnostic disagreement in 8 cases (9.1%). Of the cases with discrepancies, 6 (6.8%) were of major significance. Of the gastrointestinal cases, 87 (82.1%) of 106 cases showed no discrepancies. Discrepancies were noted in 19 cases (17.9%), including missing or unclear information in 3 cases (2.8%) and diagnostic disagreements in 16 cases (15.1%). The cases with discrepancies included 8 cases (7.5%) for which the change was of major clinical significance. CONCLUSIONS Routine pathologic review of gastrointestinal and hepatobiliary cases revealed notable discrepancies in diagnoses. In 14 cases (7.2%), the change in diagnosis or additional information had a significant effect on the proper treatment or a significant prognostic implication. Routine review of all pertinent pathologic material should be performed on all patients being transferred to a second institution for treatment or second opinion.

Pathologic Findings in Reduction Mammaplasty Specimens

Reduction mammaplasty (RM) is a common surgical procedure that yields a variable amount of tissue for pathologic examination. Occult breast carcinomas are detected rarely in these specimens. We evaluated the pathologic findings in RM specimens performed in our institution during an 11.5-year period (July 1989 to December 2000). A total of 560 patients who had undergone RM were identified, 503 bilateral and 57 unilateral. The average number of blocks submitted per breast was 3.9 (range, 1-23). Pathologic changes were present in 338 cases (60.4%). Unsuspected carcinomas (small invasive carcinomas, 3; ductal carcinoma in situ, 1) were found in 4 cases (0.7%). Atypical ductal and/or atypical lobular hyperplasia were identified in 8 cases (1.4%). Lesions associated with a mildly increased carcinoma risk (moderate/florid ductal hyperplasia, sclerosing adenosis, and papilloma) were identified in 52 cases (9.3%). Other findings included fibrocystic changes, fibrosis, mild ductal hyperplasia, fibroadenoma, and adenosis. Pathologic examination of RM specimens provides important clinical information and should be performed routinely.

Quality assurance of second opinion pathology in gynecologic oncology

OBJECTIVE To determine the effect of routine second review of pathologic material that was sent to Ohio State University before initiation of therapy. METHODS All the gynecologic-oncologic histopathology review diagnoses made during a 1-year period were compared with original pathologic diagnoses. When there was a discrepant diagnosis with the second interpretation, the case was reviewed by at least two pathologists. Discrepancies were coded as no diagnostic disagreement, no diagnostic disagreement but pertinent information not included, diagnostic disagreement without clinical consequences, diagnostic disagreement with minor clinical significance, or diagnostic disagreement with major clinical significance. Proportions and confidence intervals were calculated. RESULTS Pathology reports from 295 referred patients were reviewed. Two hundred forty-five (83.1%) showed no discrepancy. Discrepancies were found in 50 cases (16.9%). There was significant information missing in four cases (1.4%), diagnostic disagreement with no clinical significance in 22 cases (7.5%), and diagnostic disagreement with minor clinical significance in 10 cases (3.4%). In 14 cases (4.7%, 95% confidence interval 2.28, 7.12) the changes in diagnoses had major therapeutic or prognostic implications that included changes from malignant or low malignant potential to benign (seven cases), malignant to low malignant potential (three cases), change in tumor type (two cases), and assessment of invasion (two cases). The cost of reviewing 295 specimens was approximately

Carcinosarcoma of the Urinary Bladder—An Aggressive Tumor With Diverse Histogenesis A Clinicopathologic Study of 4 Cases and Review of the Literature

39,235. The cost of identifying each major discrepancy was about

MOC31 immunoreactivity in primary and metastatic carcinoma of the liver. Report of findings and review of other utilized markers.

2802. CONCLUSION Routine pathology review of gynecologic-oncologic cases before definite treatment revealed notable discrepancies in diagnoses. In 4.7% of cases, the change in diagnosis had a major effect on proper treatment planning or a significant prognostic implication.

Hereditary and somatic DNA mismatch repair gene mutations in sporadic endometrial carcinoma

OBJECTIVE Carcinosarcomas of urinary bladder are rare malignant neoplasms. Seventy-eight cases have been previously described. The histologic composition of these tumors is variable, but diagnosis requires the presence of both epithelial and mesenchymal malignant components. We report 4 additional cases, with an emphasis on unusual histologic features. METHODS Histologic and immunohistochemical examinations were performed on bladder tumors from 4 patients. Clinicopathologic features of previously reported and current cases were reviewed and summarized. RESULTS Four patients (3 men, 1 woman) age 54 to 77 years were found to have polypoid masses in the urinary bladder. In all cases, histologic examination showed biphasic neoplasms with distinct mesenchymal and epithelial components. The morphologic and immunohistochemical characteristics of the tumors varied. One of the cases was remarkable for the presence of liposarcoma, malignant peripheral nerve sheath tumor, and micropapillary urothelial carcinoma. Two of the patients died 2 years after diagnosis, which is consistent with the previously reported aggressive nature of urinary bladder carcinosarcomas. CONCLUSIONS Carcinosarcomas of the urinary bladder are rare, aggressive malignant neoplasms. To our knowledge, a liposarcomatous component has been reported in only 1 case previously, and components of micropapillary urothelial carcinoma and malignant peripheral nerve sheath tumor have not been reported previously in carcinosarcomas of the urinary bladder. Because of the aggressive biologic behavior of these tumors, they should be identified promptly and treated appropriately.

Seminal vesicle cystadenoma : A case report and literature review

Differentiating between primary tumors of the liver and metastatic lesions can, at times, be difficult. Various histochemical and immunohistochemical methods have been used in an effort to better delineate between hepatocellular carcinoma (HCC), especially the microglandular variant, primary cholangiocarcinoma, and metastatic adenocarcinoma; these ancillary studies can yield less than satisfactory results. Recently, anti-MOC31, a monoclonal antibody directed against a cell surface glycoprotein, has been shown to be helpful in distinguishing between adenocarcinoma and mesothelioma. This study addresses whether this antibody might be helpful in distinguishing between HCC, primary cholangiocarcinoma, and metastatic adenocarcinoma in the liver. Formalin-fixed, paraffin-embedded tissue sections from 15 HCC (including 10 microglandular variants), 14 primary cholangiocarcinomas, and 33 metastatic adenocarcinomas (7 colon, 1 lung, 8 breast, 4 GE jct/gastric, 9 pancreas, 2 small intestine, 1 renal, 1 ovary) were immunostained with anti-MOC 31 (1:40, Dako) after protease digestion and biotin block using a modified ABC technique. Positive staining was limited to membrane based reactivity; controls stained appropriately. Immunoreactivity for MOC31 was observed in 14 of 14 cholangiocarcinomas and 33 of 33 metastatic tumors. Staining was diffuse, intense, and readily interpretable, with rare exceptions. All 15 cases of HCC were negative. We conclude that cholangiocarcinoma and metastatic adenocarcinoma from a variety of sites express MOC31; HCC is uniformly negative for this marker. Anti-MOC31 may prove useful in the evaluation of liver neoplasms where primary hepatocellular and adenocarcinoma enter the differential diagnosis; it is not useful in separating primary cholangiocarcinoma from metastatic adenocarcinoma.

Diffuse leiomyomatosis of the uterus: a case report with clonality analysis

Editor—Endometrial cancer (EC) is the second most common malignancy in the hereditary non-polyposis colorectal cancer (HNPCC) syndrome.1 In a recent large study, cumulative cancer incidences by the age of 70 in HNPCC mutation carriers were: colorectal 82%, endometrial 60%, gastric 13%, and ovarian 12%.2 Interestingly, in female mutation carriers the incidence of endometrial cancer (60%) exceeded that of colorectal cancer (CRC) (54%), as had been suggested earlier.2 3 Predisposition to HNPCC is the result of germline mutations in the mismatch repair genes.4 Detectable mutations in the two major genes, MLH1 and MSH2 , account for some 3% of all colorectal cancers.5 One might therefore assume that a similar proportion of all endometrial cancer patients would have such mutations; however, in a number of studies addressing this question, extremely few germline mutations have been found. Summarising the studies by Katabuchi et al ,6Kobayashi et al ,7 Lim et al ,8 Gurin et al ,9 and Kowalski et al ,10 only one germline mutation (in MLH1 ) was found in a total of 352 EC patients (0.3%). In these studies, mutations were sought in all patients whose tumours were microsatellite instability (MSI) positive. Recent reports have suggested that MSH6 might account for many endometrial cancers and that families with these mutations show atypical features of HNPCC with endometrial and ovarian cancers outnumbering colorectal cancers.11 12Additionally, MSI, a hallmark of HNPCC, was low in most tumours associated with MSH6 mutations or was preferentially shown by mononucleotide repeats rather than dinucleotide repeats.12-14 Previous studies have reported that 9-25% of sporadic endometrial cancers display microsatellite instability .7 9 15-18 In the majority of cases, this instability arises through hypermethylation of the MLH1 promoter region.9 19-21 This epigenetic change results …