Prophylactic salpingectomy for prevention of ovarian cancer at the time of elective laparoscopic cholecystectomy

Background

Most serous ovarian cancers are now understood to originate in the fallopian tubes. Removing the tubes (salpingectomy) likely reduces the risk of developing high‐grade serous ovarian cancer. Numerous gynaecological societies now recommend prophylactic (or opportunistic) salpingectomy at the time of gynaecological surgery in appropriate women, and this is widely done. Salpingectomy at the time of non‐gynaecological surgery has not been explored and may present an opportunity for primary prevention of ovarian cancer.

Methods

This study investigated whether prophylactic salpingectomy with the intention of reducing the risk of developing ovarian cancer would be accepted and could be accomplished at the time of elective laparoscopic cholecystectomy. Women aged at least 45 years scheduled for elective laparoscopic cholecystectomy were recruited. They were counselled and offered prophylactic bilateral salpingectomy at the time of cholecystectomy. Outcome measures were rate of accomplishment of salpingectomy, time and procedural steps needed for salpingectomy, and complications.

Results

A total of 105 patients were included in the study. The rate of acceptance of salpingectomy was approximately 60 per cent. Salpingectomy was performed in 98 of 105 laparoscopic cholecystectomies (93·3 per cent) and not accomplished because of poor visibility or adhesions in seven (6·7 per cent). Median additional operating time was 13 (range 4–45) min. There were no complications attributable to salpingectomy. One patient presented with ovarian cancer 28 months after prophylactic salpingectomy; histological re‐evaluation of the tubes showed a previously undetected, focal serous tubal intraepithelial carcinoma.

Conclusion

Prophylactic salpingectomy can be done during elective laparoscopic cholecystectomy.

[Mesenchymal and mixed uterine tumors : Current overview and practical aspects]

Benign leiomyomas are the most frequent mesenchymal tumors of the uterus. In contrast, uterine sarcomas are very rare. Leiomyosarcomas are the most frequent sarcomas followed by endometrial stromal sarcomas (ESS). Leiomyosarcomas are characterized by marked nuclear atypia and high mitotic count and may also show tumor cell necrosis and myometrial and vascular invasion. For cases of diagnostic uncertainty, the category of smooth muscle tumor of uncertain malignant potential (STUMP) may be considered but should be rarely used. Besides low-grade ESS and stromal nodules, a category of high-grade ESS was reconsidered by the WHO in 2014. High-grade ESS are characterized by fibromyxoid and round cell histology, myoinvasive growth, and immunoreactivity for cyclin D1 and BCOR and distinct gene fusions involving YWHAE and BCOR, respectively. The very rare undifferentiated uterine sarcomas need to be redefined due to overlap with high-grade ESS. Uterine tumors resembling ovarian sex cord tumors (UTROSCT) rarely behave malignant, but need to be distinguished from endometrial carcinomas. Mixed epithelial and mesenchymal tumors of the uterus are rare with carcinosarcomas occurring more frequently than adenosarcomas. For prognosis of adenosarcomas the recognition of sarcomatous overgrowth is crucial. Carcinosarcomas are histologically heterogeneous although genetically clonal; biologically they are considered as undifferentiated carcinomas. There will be an increasing importance of molecular pathology for the classification of rare and unusual mesenchymal uterine tumors.

[Precursor lesions of endometrial carcinoma]

The 2014 WHO classification distinguishes between endometrial hyperplasia without atypia (EH) and atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN). AEH/EIN is characterized by crowded glands with cytologically atypical epithelium separated by little intervening stroma. Cellular atypia is characterized by nuclear enlargement and rounding, pleomorphism, loss of polarity, and presence of nucleoli. The diagnosis of atypia is facilitated by comparison with areas of adjacent normal and non-atypical glands, respectively. AEH/EIN is often associated with squamous but also secretory and mucinous metaplasia. Loss of PTEN and/or PAX2 immunoreactivity occurs in up to two thirds of AEH/EIN. In contrast, invasive low-grade endometrioid carcinoma shows confluent growth with loss of stroma and formation of labyrinth-like or cribriform structures. Differential diagnosis includes different forms of metaplasias, papillary proliferations, and hyperplastic polyps. Epithelial metaplasia may be present in various benign endometrial lesions as well as in endometrioid adenocarcinoma. AEH/EIN may also occur in endometrial polyps. Progestin therapy of AEH/EIN has low level of evidence but frequently leads to complete regression. Serous intraepithelial carcinoma (SEIC) is characterized by high-grade cellular atypia and polymorphism, detachment of cells, a mutant immunoreactive pattern for the P53 and an increased Ki67 labeling index. Although designated as precursor of serous carcinoma of the endometrium, biologically it is considered a non-invasive serous carcinoma since it may already be associated with massive extrauterine spread.

[Pitfalls and common problems in the differential diagnosis of epithelial ovarian tumors]

Epithelial ovarian tumors may cause various diagnostic problems of practical relevance. For the distinction between cystadenomas and borderline tumors/atypically proliferative tumors, a minimum extent of 10% of the atypical epithelial proliferation has been suggested by the WHO. The micropapillary variant of serous borderline tumors is more frequently associated with invasive growth and extraovarian lesions. Extraovarian lesions of borderline tumors are relevant for prognosis and cause a higher stage; their classification is crucial. Traditionally, they were classified into noninvasive and invasive implants based on their morphology. Based on the 2014 WHO classification, invasive lesions should be designated as low-grade serous carcinomas whereas only noninvasive lesions are considered implants. The most frequent invasive growth pattern in low-grade serous carcinomas consists of haphazardly arranged tumor cell nests and small papillae in clefts, whereas mucinous and endometrioid carcinomas mainly show a confluent glandular pattern with maze-like and cribriform structures. For metastatic mucinous tumors a nodular growth pattern is characteristic; ruling them out requires clinical information including imaging and immunohistochemistry. Differential diagnosis between low-grade and high-grade serous carcinoma is based on the degree of nuclear polymorphism and mitotic count. The seromucinous tumor category replaces the endocervical subtype of mucinous tumors and resembles histologically, biologically, and on the molecular level serous and endometrioid tumors. Endometrioid tumors with fibromatous stroma need to be distinguished from tumors with Sertoli cell differentiation and well-differentiated neuroendocrine tumors. For differential diagnosis of epithelial ovarian tumors, in particular carcinomas, a panel of antibodies for immunohistochemistry is very useful under consideration of histomorphology.

[Categorization of uterine cervix tumors : What's new in the 2014 WHO classification]

In the 2014 WHO classification, squamous cell precursor lesions are classified as low-grade and high-grade intraepithelial lesions. LSIL corresponds to CIN1, HSIL includes CIN2 and CIN3. Only adenocarcinoma in situ (AIS) is accepted as precursor of adenocarcinoma and includes the stratified mucin-producing intraepithelial lesion (SMILE). Although relatively rare, adenocarcinoma and squamous cell carcinoma can be mixed with a poorly differentiated neuroendocrine carcinoma. Most cervical adenocarcinomas are low grade and of endocervical type. Mucinous carcinomas show marked intra- and extracellular mucin production. Almost all squamous cell carcinomas, the vast majority of adenocarcinomas, and many rare carcinoma types are HPV related. For low grade endocervical adenocarcinomas, the pattern-based classification according to Silva should be reported. Neuroendocrine tumors are rare and are classified into low-grade and high-grade, whereby the term carcinoid is still used.

[Metastatic mechanisms of uterine malignancies and therapeutic consequences]

Malignancies of the uterus metastasize by direct invasion of neighboring structures, lymphatically or hematogenously. Endometrial and cervical cancers lymphatically spread to the pelvic and para-aortic lymph nodes. For endometrial cancer the depth of myometrial invasion, lymphosvascular space involvement (LVSI) and a microcystic, elongated and fragmented (MELF) glandular invasion pattern are predictors for lymph node metastases. Metastases to the pelvic lymph nodes occur in approximately 10 % of endometrial cancer patients and in 30 % of these cases the para-aortic lymph nodes are also involved. Sentinel lymph node biopsy is possible for clinical stage I endometrial cancer and early stages of cervical cancer but is not yet routine. The presence of LVSI is considered to be the strongest predictor of distant metastases, particularly if assessed by immunohistochemistry with antibodies against factor VIII-related antigen or CD31. Endometrioid and clear cell carcinomas can hematogenously metastasize to the lungs, bones, liver and brain and can rarely be manifested as a solitary metastasis. In contrast, serous carcinomas can show extensive peritoneal spread. To date molecular biomarkers cannot predict the occurrence of distant metastasis. Overexpression of P53, p16 and L1CAM have been identified as negative prognostic factors and are associated with the prognostically unfavorable serous tumor type. The metastatic spread of squamous cell cervical cancer is strongly associated with tumor volume. Microinvasive carcinomas have a very low rate of parametrial and lymph node involvement and do not require radical hysterectomy. In contrast, lymph node metastases occur in up to 50 % of bulky stages IB and II cervical cancers. Distant metastases can occur in the lungs, liver, bones and brain. Molecular biomarkers have not been shown to predict metastatic spread. In well-differentiated adenocarcinoma of the cervix the pattern of invasion is strongly predictive for the presence of lymph node metastases, irrespective of tumor size and depth of invasion.

Pathologisch-anatomische Aufarbeitung und Befundung von Dysplasien und Karzinomen der Cervix uteri*

A careful macroscopic description with selection of representative tissue for histological examination is required for quality assurance, for assessing prognostic factors and for answering legal questions in (pre)cancerous lesions of the cervix uteri. Exact and standardized gross inspection and preparation are decisive for the quality of the histopathological statement. The extent of cervical carcinomas should be given in three dimensions, including the relative depth of invasion into the cervical wall. The report should include size, type (according to the WHO classification) and grading of the tumor, the presence of lymphatic as well as blood vessel invasion and perineural involvement. The statement for resection margins should include the vaginal, parametrial, rectal and vesical directions. It is also mandatory to document the number of lymph nodes with metastatic disease in relation to the total number of nodes investigated. The staging should follow the TNM system. In the handling of conisation specimens, it is important to appropriately document localization, horizontal expansion, depth of invasion including microinvasion of any dysplastic or malignant lesions. Clockwise dissection of the conisation specimen, total submission, and step sections are recommended. The preparation of exenteration specimens is a highly skilled job: the exact tumor dimension should be given in its relation to all resected organs and structures with special focus on resection margins.

Pathologisch-anatomische Aufarbeitung und Befundung von Lymphknoten bei gynäkologischen Malignomen

The nodal status is one of the strongest prognostic factors in gynecologic malignancies. Metastatic involvement of regional and distant lymph nodes represents the selection basis for adjuvant therapy in a large number of solid neoplasms. The number of resected lymph nodes is one of the most important parameters in the quality control of the surgical procedure, in particular with respect to radicality. The present paper provides recommendations for gross dissection, laboratory procedures and reporting for lymph node biopsies, lymph node dissections and sentinel lymph node biopsies (SLN) for cancers of the vulva, vagina, uterine cervix, endometrium, Fallopian tubes and the ovaries, submitted for the evaluation of metastatic disease. The pathologic oncology report should include information about the number and size of resected lymph nodes, the number of involved lymph nodes with the maximum size of metastases and the presence of paranodal infiltration. In addition, the detection of isolated tumor cells should be reported, particularly with respect to the detection method (immunostains or molecular methods). In cases of metastatic disease and carcinoma of unknown primary (CUP-syndrome), information should be given regarding the primary tumor.

[Dualistic model of molecular pathogenesis in endometrial carcinoma]

Sporadic endometrial carcinoma can be divided into two biologically and clinically distinctive subtypes of which one is estrogen-related (type I), the other estrogen-unrelated (type II). Type I carcinomas occur at younger age, express estrogen (ER) and progesterone receptors (PR), are frequently associated with endometrial hyperplasia and show a good prognosis. Type II carcinomas occur at older age, are negative for ER and PR, arise in the background of atrophic endometrium and show poor prognosis. Histologically, endometrioid carcinomas correspond to type I carcinomas whereas serous carcinoma is the prototype of type II carcinomas. Endometrioid and serous carcinomas are significantly different with respect to their molecular changes. Endometrioid carcinomas frequently show microsatellite instability (MIN), PTEN and K-ras mutation but infrequently p53 mutations, loss of p16 expression and her2/neu amplification, respectively. In contrast, serous carcinomas show a high frequency of p53 mutations and often loss of p16 expression whereas MIN and PTEN and K-ras mutations are uncommon. Familial endometrial carcinoma associated with HNPCC occur about two decades earlier than sporadic carcinomas, show endometrioid histology and are frequently MIN positiv due to germline mutations of mismatch repair genes (mostly MLH1 and MSH2). During the progression of endometrioid carcinoma PTEN mutations and MIN are considered early changes since they are present in a high frequency in atypical endometrial hyperplasia whereas p53 mutations, loss of p16 expression and her2/neu amplification are considered late events since they are predominantly found in poorly differentiated tumors. In contrast, p53 mutations are considered an early event in the pathogenesis of serous carcinoma occurring already in its putative precursor endometrial intraepithelial carcinoma (EIC). The future research will focus, besides the discovery of new relevant genes, on the interaction of known genes as well as their clinical relevance.

Selective decrease of serum immunoglobulin G1 as marker for early stages of invasive breast cancer

The diagnostic value of the decrease in percentage of immunoglobulin G1 (%lgG1) in breast cancer was analyzed with special emphasis on early tumor stages. IgG1 and total IgG were preoperatively measured in the sera of a total of 801 individuals using a modified quantitative affinity chromatography. Group A consisted of 174 healthy individuals of both sexes, group B of 324 female patients with benign breast disease, and group C of 303 patients with invasive and non-invasive breast cancer. Within group C, 13 patients presented with intraductal carcinoma, and 22 patients with a pT1a-tumour (diameter less than 0.5 cm). The %IgG1 values were compared among groups A, B and C. In addition, correlations were sought between %IgG1 values of group C and tumor size, stage (UICC), histopathological grade and oestrogen (ER) and progesteron receptor (PR) expression. The mean value of %IgG1 in group A was 63.3 +/- 0.5 s.e.m., in group B 57.75 +/- 0.4 s.e.m. and in group C 52.37 +/- 0.5 s.e.m. The differences of mean values were highly significant between all three groups. Sensitivity and specificity of %IgG1 to discriminate between group A and C were 75% and 87%, and between group B and C 62% and 63%, respectively. The significant decrease of %IgG1 in total serum IgG is able to distinguish patients with breast cancer of more than 5 mm in diameter from healthy controls and patients with benign breast diseases. Finally, calculated posterior probabilities revealed that within certain concentration limits %lgG1 may provide predictive information with high probabilities.

A binary architectural grading system for uterine endometrial endometrioid carcinoma has superior reproducibility compared with FIGO grading and identifies subsets of advance-stage tumors with favorable and unfavorable prognosis

The International Federation of Gynecology and Obstetrics (FIGO) grading of uterine endometrial endometrioid carcinoma requires evaluation of histologic features that can be difficult to assess, including recognition of small amounts of solid growth, distinction of squamous from nonsquamous solid growth, and assessment of degree of nuclear atypia. The authors describe a novel, binary architectural grading system that uses low-magnification assessment of amount of solid growth, pattern of invasion, and presence of necrosis to divide endometrioid carcinomas into low- and high-grade tumors. The authors analyzed its performance for predicting prognosis and with respect to intra- and interobserver reproducibility. A total of 141 endometrioid carcinomas from hysterectomy specimens were graded according to the FIGO system, nuclear grading, and the binary architectural system. A tumor was classified as high grade if at least two of the following three criteria were present: (1) more than 50% solid growth (without distinction of squamous from nonsquamous epithelium); (2) a diffusely infiltrative, rather than expansive, growth pattern; and (3) tumor cell necrosis. For tumors that were confined to the endometrium, only percent solid growth and necrosis were evaluated, and those with both solid growth of more than 50% and necrosis were considered high grade. All tumors were graded independently by three pathologists on two separate occasions. Both inter- and intraobserver agreement using the binary grading system (kappa = 0.65 and 0.79) were superior compared with FIGO (kappa = 0.55 and 0.67) and nuclear grading (kappa = 0.22 and 0.41). The binary grading system stratified patients into three distinct prognostic groups. Patients with stage I low-grade tumors with invasion confined to the inner half of the myometrium (stages IA and IB) had a 100% 5-year survival rate. Patients with low-grade tumors that invaded beyond the outer half of the myometrium (stage IC and stages II-IV) and those with high-grade tumors with invasion confined to the myometrium (stages IB and IC) had a 5-year survival rate of 67% to 76%. In striking contrast to patients with advance-stage low-grade tumors, patients with advance-stage high-grade tumors had a 26% 5-year survival rate. This binary grading system has advantages over FIGO and nuclear grading that permit greater interobserver and intraobserver reproducibility and should be tested in other studies of endometrial endometrioid carcinomas to validate its reproducibility and use for segregating patients into different prognostic groups.

[Point mutation of thyrotropin receptors as the main cause of autonomously functioning thyroid nodules: experiences in the framework of our Styrian patients]

Autonomously functioning thyroid nodules are frequently associated with mutations of the thyrotropin receptor. We analyzed a part of exon 10 of the thyrotropin receptor gene (base pairs 1762-1976) by direct sequencing and found missense mutations in 5 of 14 cases (codons 629, 631, 632, 633). Histologically, 3 of the 14 nodules were adenomas whereas 11 were hyperplasias. Nodules with mutations did not show significant differences from nodules without mutations with respect to age, histology, size, additional (non-functional) nodules and clinical symptomatology. Our results confirm that thyrotropin receptor mutations are involved in the development of autonomously functioning thyroid nodules. In this context, the terms hyperplasia and neoplasia should be reevaluated.

Altered expression of hMLH1 and hMSH2 protein in endometrial carcinomas with microsatellite instability

Microsatellite instability (MI) has been observed in approximately 20% of presumably sporadic cases of uterine endometrioid carcinoma (UEC). A previous mutational analysis of the 4 known DNA mismatch repair genes (hMSH2, hMLHI, hPMS1, and hPMS2) on a small number of Ml-positive tumors detected mutations in only 2 of 8 cases, both in hMSH2. To further explore the underlying cause of MI in UEC, we analyzed the protein expression of hMSH2 and hMLHI in UEC of known MI status. Formalin-fixed, paraffin-embedded archival tissue from 21 UECs was analyzed by immunoperoxidase staining with monodonal antibodies against hMLH1 and hMSH2 protein. Tumors were evaluated for presence of nuclear staining by 3 investigators. Lack of nuclear hMLHI staining was found in 7 of 13 carcinomas with MI, but in none of 8 carcinomas without MI (Fischer's exact, 0.018). Lack of nuclear hMSH2 staining was found in 3 of the MI-positive cases, but none of the MI-negative cases (not statistically significant). Taken together, lack of nuclear staining of either hMLH1 or hMSH2 was found in 9 of 13 cases with MI and in none of 8 cases without MI (Fischer's exact, 0.005). We conclude that MI in sporadic UEC appears to be associated with lack of expression of either hMLH1 or hMSH2, suggesting that inactivation of these genes may be responsible for MI in most MI-positive sporadic UECs.

The frequency of p53, K-ras mutations, and microsatellite instability differs in uterine endometrioid and serous carcinoma: evidence of distinct molecular genetic pathways

BACKGROUND

The two most common types of uterine endometrial carcinoma, endometrioid (UEC) and serous (USC), differ in their histopathologic appearance and biologic behavior. Recent studies suggest that these differences may be associated with distinct molecular genetic alterations.

METHODS

In the current study, the authors compared the frequencies of K-ras and p53 mutations and microsatellite instability (MI) between UEC and USC by analyzing all 3 molecular genetic changes in one set of tumors. Furthermore, the distribution of these molecular genetic alterations was determined among UECs of different histopathologic grade. The authors analyzed 58 UECs with known MI status for K-ras and p53 mutations. The K-ras and p53 genes were analyzed in 45 and 6 cases of USC, respectively. These results were combined with previous data on p53 mutations (21 cases) and MI (34 cases) in USC.

RESULTS

MI was present in 16 of 57 UECs (28%) but in none of 34 USCs. p53 mutations were found in 7 of 42 UECs (17%) and 25 of 27 USCs (93%) by direct sequencing of exons 5-8. UECs and USCs with p53 mutations showed strong immunoreactivity for p53 in about 85% of the cases, whereas about 15% of the cases were immunonegative. K-ras mutations at codon 12 were found in 15 of 58 UECs (26%) and in only 1 of 45 USC (2%) by dot blot oligohybridization after polymerase chain reaction amplification of exon 1. Notably, the frequency of both K-ras and p53 mutations and MI was significantly different between UEC and USC (P < 0.001). In UECs, MI and K-ras mutations occurred in low grade as well as in high grade tumors, whereas p53 mutations were present almost exclusively in high grade tumors.

CONCLUSIONS

The results of this study suggest that different molecular genetic pathways are involved in the pathogenesis of UEC and USC and that low grade UEC may progress to high grade UEC. These findings support the hypothesis that UEC and USC are separate entities and suggest that different molecular genetic alterations may be responsible for their distinct morphology and biologic behavior.

Characterization of the dose-response of CYP1B1, CYP1A1, and CYP1A2 in the liver of female Sprague-Dawley rats following chronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

One of the current knowledge gaps in the evaluation of risk for human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the relationship between gene expression induced by TCDDmore complex biological responses such as altered growth, differentiation, and neoplasia. This study investigates the dose-dependent expression of CYP1A1, CYP1A2,CYP1B1 in the livers of female Sprague-Dawley rats chronically exposed to TCDD. Animals were treated biweekly for 30 weeks with daily averaged doses of 0 to 125 ng TCDD/kg/day. Immunoblot analysis showed that protein levels for CYP1B1, CYP1A1, CYP1A2 exhibited a dose-dependent induction by TCDD. However, CYP1A1 and CYP1A2 protein levels were approximately 100-fold higher than CYP1B1, which could not be detected by either immunoblot analysis or immunohistochemistry in the livers of rats treated with TCDD for 30 weeks at a dose-equivalent less than 35.7 ng/kg/day. In control animals, CYP1A1CYP1A2 RNA levels, measured by quantitative RT-PCR, were 1100-15,000-fold higher than that of CYP1B1, respectively. TCDD induced CYP1B1 RNA levels at all doses, although absolute TCDD-induced levels of CYP1A1CYP1A2 at the highest dose (125 ng/kg/day) were more than 40-fold higher than that of CYP1B1. While the liver concentration of TCDD required for half-maximal induction of CYP1A1, CYP1A2,CYP1B1 RNA levels was similar, the shaping parameter (Hill coefficient) of the dose-response curve for CYP1B1 was significantly higher than that for CYP1A1 or CYP1A2. The low level of TCDD-induced CYP1B1 expression in the liver relative to that of the CYP1A1CYP1A2 suggest that, if CYP1B1 is involved in TCDD-induced hepatocarcinogenesis, its endogenous function is likely to be uniquenot overlapping with that of CYP1A1 or CYP1A2.

Comparison of estrogen and progesterone receptor, Ki-67, and p53 immunoreactivity in uterine endometrioid carcinoma and endometrioid carcinoma with squamous, mucinous, secretory, and ciliated cell differentiation

An analysis of 77 uterine endometrioid carcinomas was performed to compare pure endometrioid carcinomas and endometrioid carcinomas with various types of cellular differentiation for the expression of estrogen (ER) and progesterone (PR) receptors, p53, and Ki-67 and to correlate these findings with clinicopathologic features. Forty-three pure endometrioid carcinomas and 34 endometrioid carcinomas displaying additional types of cellular differentiation in at least 10% of the tumor (16 squamous, 11 mucinous, four ciliated cell, and three secretory) were analyzed. In 8 of the 16 tumors with squamous differentiation, the squamous component was histologically benign (low grade), and in eight tumors it was histologically malignant (high grade). In tumors showing various types of cellular differentiation except those with a high-grade squamous component, comparison of the endometrioid glandular component with the squamous, mucinous, secretory, and ciliated cell components showed that ER/PR, Ki-67, and p53 expression were generally higher in the glandular component compared with the various differentiated components. These findings parallel the changes that occur in the endometrium in the secretory phase of the menstrual cycle and, therefore, suggest that the differentiated components have undergone terminal differentiation. In contrast, in endometrioid carcinomas with a high-grade squamous component, Ki-67 and p53 expression were the same in the glandular and squamous components suggesting that squamous epithelium in these tumors represented another pathway of cellular differentiation but not one that was terminally differentiated. Endometrioid carcinomas with a high-grade squamous component had significantly higher grade (P = .002), stage (P < .001), cellular proliferation index (P = .0005), and worse outcome (P = .0009) compared with tumors with the other types of cellular differentiation, including those with a low-grade squamous component and pure low-grade endometrioid carcinomas. In addition, carcinomas with a high-grade squamous component occurred in older women and were more frequently associated with atrophic endometrium and less replacement hormone therapy, but the differences were not statistically significant. In conclusion, endometrioid carcinomas with various types of cellular differentiation can be broadly divided into two groups. Tumors with mucinous, secretory, and ciliated cell differentiation and those with a low-grade squamous component are similar to pure low-grade endometrioid carcinomas in that most have high ER and PR expression, low cellular proliferation indices, low p53 immunoreactivity, and good prognosis. In contrast, endometrioid carcinomas with a high-grade squamous component lack expression of ER and PR, have high cellular proliferation indices, often express p53, and have a prognosis similar to poorly differentiated endometrioid carcinomas.

Fatty acid synthase expression in endometrial carcinoma: correlation with cell proliferation and hormone receptors

BACKGROUND

Fatty acid synthase (FAS), a biosynthetic enzyme, normally functions in the liver to convert dietary carbohydrate to fat, but it is minimally expressed in most other normal adult tissues. FAS is expressed at markedly elevated levels in subsets of human breast, ovarian, and prostate carcinomas that are associated with poor prognoses. During the menstrual cycle, the expression of FAS in the human endometrium is closely linked to the expression of the proliferation antigen Ki-67, estrogen receptor (ER), and progesterone receptor (PR).

METHODS

This study reports the expression patterns of these antigens in 35 endometrial carcinomas as determined by immunohistochemical analysis.

RESULTS

All cases demonstrated a close direct correlation between FAS and Ki-67 expression. Average FAS expression levels were correlated with tumor grade. Twenty-five carcinomas that were positive for ER and PR showed close correlation in expression of FAS, Ki-67, and hormone receptors. Individual tumors displayed varying degrees of heterogeneity of expression. A few well-differentiated carcinomas showed very low expression of all four antigens, similar to the antigenic profile of secretory endometrium. Nine high grade carcinomas that were negative for ER and PR also showed close correlation in expression of FAS and Ki-67 with uniformly high expression.

CONCLUSIONS

These data suggest the following hypothesis: In hormone-dependent endometrial cells, FAS expression is part of the estrogen-driven cellular response that leads to proliferation; however, its linkage to proliferation is such that FAS expression is maintained in proliferating cells in endometrial carcinomas that acquire hormone independence. The use of these four antibodies as a panel may increase the diagnostic utility of ER and PR immunohistochemistry for tumor classification and prediction of the responsiveness of tumors to hormonal therapy.

Clear cell carcinoma of the endometrium is characterized by a distinctive profile of p53, Ki-67, estrogen, and progesterone receptor expression

This study was designed to analyze certain clinicopathological features and the profile of p53, Ki-67, estrogen (ER), and progesterone (PR) receptor expression of clear cell carcinoma of the endometrium and to determine whether the pathogenesis of clear cell carcinoma can be accommodated by a dualistic model of endometrial carcinogenesis. In this model, endometrioid carcinoma develops from endometrial hyperplasia under unopposed estrogenic stimulation, and serous carcinoma develops in atrophic endometrium from a putative precursor lesion designated endometrial intraepithelial carcinoma (EIC). Twenty-one clear cell carcinomas of the endometrium were analyzed and compared with 77 endometrioid carcinomas of all grades and 30 serous carcinomas. Clear cell carcinomas showed a distinctive immunoprofile characterized by immunonegativity for ER and PR, low immunoreactivity for p53, and a high Ki-67 proliferation index. ER, PR, and Ki-67 expression were similar to serous carcinoma, but p53 expression was significantly lower in clear cell carcinoma (P < .05). ER and PR expression were significantly lower, and the Ki-67 proliferation index was significantly higher in clear cell carcinoma compared with endometrioid carcinomas (P < .05). p53 expression tended to be higher in clear cell carcinoma compared with endometrioid carcinoma, but the difference was not statistically significant. In contrast to endometrioid carcinoma, clear cell carcinoma was rarely associated with endometrial hyperplasia and serous carcinoma was not. Subdividing clear cell carcinoma morphologically into one that resembled serous carcinoma (clear cell carcinoma with serous features) and another that did not (typical clear cell carcinoma) showed that clear cell carcinoma with serous features had a higher Ki-67 proliferation index than typical clear cell carcinoma, although expression of ER, PR, and p53 were similar. Clear cell carcinoma with serous features was associated with EIC in 50% and was not associated with endometrial hyperplasia. In contrast, typical clear cell carcinoma was associated with endometrial hyperplasia in 40% and was not associated with EIC. In summary, this study provides evidence that clear cell carcinoma of the endometrium, like serous carcinoma, is estrogen independent and shows a high Ki-67 proliferation index. In contrast to serous carcinoma, strong p53 expression occurred less frequently in clear cell carcinoma and predominantly in clear cell carcinoma with serous features. The findings suggest that the molecular events that underlie the development of clear cell carcinoma differ from those of endometrioid and serous carcinoma.

Induction and localization of cytochrome P450 1B1 (CYP1B1) protein in the livers of TCDD-treated rats: detection using polyclonal antibodies raised to histidine-tagged fusion proteins produced and purified from bacteria

Knowledge of the response of cytochrome P450 1B1 (CYP1B1) to exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in both humans and rodents is limited. To improve the analysis of CYP1 proteins, specific CYP1B1 and CYP1A1 polypeptides were expressed as hexahistidine-tagged fusion proteins in Escherichia coli, purified to homogeneity and used to produce polyclonal antibodies in rabbits. Immunoblot analyses showed that these antibodies were specific and sensitive, detecting both the human and rat forms of the respective isozymes and exhibiting negligible cross-reactivity between the two known CYP1 subfamilies. We show that CYP1B1, CYP1A1 and CYP1A2 protein levels were induced in the livers of female Sprague-Dawley rats following either acute (single dose of 25 microg TCDD/kg) or chronic (125 ng TCDD/kg/day for 30 weeks) exposure to TCDD. CYP1B1 protein exhibited a dose-response to TCDD that was different from those of CYP1A1 and CYP1A2. CYP1B1 induction appeared to be less sensitive to TCDD exposure, with induction occurring at higher doses of TCDD than that required for induction of CYP1A1 or CYP1A2. Immunohistochemical analysis showed that in animals chronically exposed to TCDD (35 ng/kg/day for 30 weeks), CYP1B1 was induced only in centrilobular hepatocytes, a pattern of expression similar to that of CYP1A1 and CYP1A2. These observations of cellular co-localization of the CYP1 cytochromes in livers of TCDD-treated rats and apparent differences in both protein amounts and dose-response are indicative of both common and unique regulation of CYP1 induction.

A dualistic model for endometrial carcinogenesis based on immunohistochemical and molecular genetic analyses

Clinicopathological, immunohistochemical and molecular genetic analyses of endometrial carcinoma suggest different pathogenetic pathways for endometrioid and serous carcinoma. Most endometrioid carcinomas are associated with endometrial hyperplasia, are ER/PR positive, p53 negative and express low Ki-67. In contrast, almost all serous carcinomas develop from endometrial intraepithelial carcinoma (EIC) in a background of atrophy. These tumors are ER/PR negative, strongly express p53 and show high Ki-67 labeling. On the molecular genetic level, 25-30% of endometrioid carcinomas show microsatellite instability (MI), 25-30% harbor mutant K-ras and less than 10% have mutant p53. In contrast, more than 90% of serous carcinomas have p53 mutations, 2% K-ras mutations and none MI. Among endometrioid carcinomas, K-ras mutations occur most frequently in FIGO grade 2 and 3 tumors and p53 mutations in FIGO grade 3 tumors. In contrast, MI is equally distributed among all FIGO grades. These findings support the view that endometrioid carcinoma develops slowly in a progressive fashion from endometrial hyperplasia. Mutation of p53 occurs late in tumor progression. Thus, endometrioid carcinogenesis resembles the proposed model for colorectal carcinogenesis. In contrast, serous carcinoma develops rapidly from EIC in a background of atrophy. Mutation of p53 occurs early in serous carcinogenesis and this may account for the highly aggressive behavior of this tumor.

[Point mutations of the thyrotropin receptor gene in autonomously functioning thyroid gland nodules: correlation with clinical findings and morphology]

Seventeen autonomously functioning thyroid nodules (AFTN) were analyzed for the most frequent mutations of the thyrotropin (TSH) receptor gene at codons 619, 631, 632 and 633. DNA was extracted from formalin-fixed, paraffin-embedded samples from both nodules and surrounding tissue after micro- or macrodissection. A fragment of the TSH receptor gene (bp 1762-1976) encoding the third cytoplasmic loop and the sixth transmembranous domain was amplified by PCR. Screening for mutations at codons 619, 631, 632 and 633 was performed by restriction enzyme analysis using Asp 718, Hph I, Taq I and EcoR I, respectively. For verification, cases with a mutated restriction site were cloned and sequenced. Mutations were found in 3 AFTNs (18%): in 2 cases at codon 632 and in 1 case at codon 631. The 2 cases with a mutation at codon 632 harbored additional mutations at codon 599 and 640, respectively, detected by sequencing. Normal thyroid tissue outside the AFTNs did not harbor mutant TSH-receptor. Mutations occurred in patients with clinical and subclinical hyperthyroidism. Mutations were associated both with total (2 cases) and partial (1 case) suppression of the surrounding thyroid tissue as noted on the scinti scan. AFTNs with TSH-receptor mutation occurred as single nodules. All 3 nodules with mutations were classified histologically as nodular hyperplasia according to the criteria of the WHO. Although the number of cases is small, our data suggest that AFTNs are clinically and morphologically heterogenous. Since the most common TSH-receptor mutations occur only in a small subset of AFTNs other molecular genetic alterations may be involved in the development of AFTNs.

Microsatellite instability is uncommon in uterine serous carcinoma

Thirty-four uterine serous carcinomas, a type of endometrial carcinoma with aggressive behavior and a high frequency (90%) of p53 gene mutations, were analyzed for microsatellite instability (MI). Genomic DNA isolated from paired normal and tumor tissue was analyzed at eight microsatellite loci (D2S119, D2S123, D2S147, D10S197, D13S175, D18S58, D18S69, and ATn) located on four different chromosomes. All 34 tumors failed to meet the criteria for MI, defined as an alteration in the size of at least two of the microsatellite loci in tumor DNA when compared with normal DNA. Only three tumors demonstrated a shift in the size of a single microsatellite locus. Previously we reported MI in 20% of uterine endometrioid carcinomas, the most common type of endometrial carcinoma. The observed difference in the MI frequency between endometrioid and serous carcinoma is statistically significant (P = 0.003). Our data demonstrate that MI is uncommon in uterine serous carcinoma and support that different pathogenetic mechanisms are involved in the development of the two most common types of endometrial carcinoma.

Severe hypotension and coma secondary to unrecognized chronic anterior hypophysitis

We report an endocrine emergency of a 52-year-old woman with chronic anterior-pituitary failure of autoimmune origin who developed hypopituitary crisis with coma and severe hypotension provoked by an intercurrent bronchopneumonia. At admission to the ICU hypopituitarism had not been diagnosed and only Hashimoto's thyroiditis with thyroid replacement therapy could be obtained from the patient's history. Although the patient presented with somatic signs suggestive of hypopituitarism, other causes of coma and hypotension had first to be excluded. In the absence of specific treatment the patient died 18 h later with refractory cardiac arrest. Diagnosis of acute decompensated chronic hypophyseal failure must be considered if hypothermia, refractory hypotension and signs of infection without fever are associated with a short stature and the loss of axillary and public hair. Waiting for laboratory confirmation of the diagnosis must not delay immediate life-saving specific glucocorticoid treatment.

Ossifying fibromyxoid tumour of the neck clinically mimicking a primary neoplasm of the thyroid gland

We present a 50-year-old male patient with an ossifying fibromyxoid tumour (OFMT) of the prethyroidal soft parts infiltrating the thyroid gland in coincidence with recurrent goitre, 20 years after strumectomy. The tumour, initially misdiagnosed as thyroid carcinoma and malignant schwannoma respectively, was histologically composed of typical solid cell-formations and shelly-like mature bone at the periphery. In addition, in the tissue adjacent to the tumour some foreign body granulomas with suture material and small proliferating nerves were present as a residual of the preceding strumectomy. We regard this finding as an indication of nerve sheat origin of OFMT. Follow up of 3 years after total thyroidectomy and local irradiation shows the patient free of recurrent and metastatic disease.

Coexistence of papillary and medullary carcinoma of the thyroid gland-mixed or collision tumour? Clinicopathological analysis of three cases

We present three thyroid carcinomas displaying medullary and papillary components. In two cases the papillary component was characterized by typical papillae with a fibrovascular core; in one a follicular variant of papillary carcinoma was found. The papillary component was dominant in two and the medullary in one case. One tumour showed clear-cut borders between the two components, the others displayed an intermingled pattern. Both tumour components were seen in lymph node metastases with immunostaining with antibodies to calcitonin, chromogranin A, carcinoembryonic antigen, other neuroendocrine markers and thyroglobulin. At least two of our cases are true mixed carcinomas probably arising from a common stem cell.