Reproducibility of current classifications of endometrial endometrioid glandular proliferations: further evidence supporting a simplified classification.

AIMS: To compare the reproducibility of the current (2003) World Health Organization (WHO), endometrial intraepithelial neoplasia (EIN) and European Working Group (EWG) classifications of endometrial endometrioid proliferations. METHODS AND RESULTS: Nine expert gynaecological pathologists from Europe and North America reviewed 198 endometrial biopsy/curettage specimens originally diagnosed as low-grade lesions. All observers were asked to classify the cases by using the categories described in each scheme: six for WHO, four for EIN, and three for EWG. The results were evaluated by kappa statistics for more than two observations. The analysis was repeated using only two major categories (benign versus atypical/carcinoma). Both the WHO and EIN classifications showed poor interobserver agreement (κ = 0.337 and κ = 0.419, respectively), whereas the EWG classification showed moderate agreement (κ = 0.530). Full agreement between pathologists occurred in only 28% for the WHO classification, 39% for the EIN classification, and 59% for the EWG classification. With only two diagnostic categories, kappa values increased in all classifications, but only the EWG classification reached a substantial level of agreement (κ = 0.621); similarly, full agreement among all pathologists increased to 70% for the WHO classification, 69% for the EIN classification, and 72% for the EWG classification. CONCLUSIONS: A two-tier classification of endometrial endometrioid proliferative lesions improves reproducibility, and should be considered for the diagnosis of endometrial biopsy/curettage specimens.

TERT Promoter Mutation c.-124C>T Commonly Occurs in Low-Grade Fibromatosis-like Metaplastic Breast Carcinoma.

CONTEXT.­: Low-grade fibromatosis-like metaplastic carcinoma (FLMC) is a very rare subtype of triple-negative metaplastic (spindle cell) breast carcinoma. It is characterized by the proliferation of spindle cells closely resembling fibromatosis, which represents a benign fibroblastic/myofibroblastic breast proliferation. Unlike most triple-negative and basal-like breast cancers, FLMC has a very low potential for metastases, but demonstrates frequent local recurrences. OBJECTIVE.­: To genetically characterize FLMC. DESIGN.­: To this end, we analyzed 7 cases by targeted next-generation sequencing for 315 cancer-related genes and performed comparative microarray copy number analysis in 5 of these cases. RESULTS.­: All cases shared TERT alterations (6 patients with recurrent c.-124C>T TERT promoter mutation and 1 patient with copy number gain encompassing the TERT locus), had oncogenic PIK3CA/PIK3R1 mutations (activation of the PI3K/AKT/mTOR pathway), and lacked mutations in TP53. TERT was overexpressed in all FLMCs. CDKN2A/B loss or mutation was observed in 4 of 7 cases (57%). Furthermore, tumors displayed chromosomal stability, with only few copy number variations and a low tumor mutational burden. CONCLUSIONS­: We conclude that FLMCs typically show the recurrent TERT promoter mutation c.-124C>T, activation of the PI3K/AKT/mTOR pathway, low genomic instability, and wild-type TP53. In conjunction with previous data of metaplastic (spindle cell) carcinoma with and without fibromatosis-like morphology, FLMC is most likely distinguished by TERT promoter mutation. Thus, our data support the notion of a distinct subgroup within low-grade metaplastic breast cancer with spindle cell morphology and associated TERT mutations.

Apoplectic leiomyomas: does ethnicity make a difference? a clinicopathologic study.

Apoplectic leiomyomas-benign uterine leiomyomas with morphologic changes including hemorrhage, hypercellularity, mitotic activity, nuclear atypia, and even necrosis-can be difficult to distinguish from uterine leiomyosarcomas. Apoplectic leiomyomas have been associated with hormonal therapy; however, the relationship between apoplectic leiomyomas, hormones, and ethnicity has not received much attention in the literature. We evaluated the relationship of hormonal therapy and ethnicity in 869 women with uterine leiomyomas, 136 of which qualified as apoplectic leiomyomas.Apoplectic leiomyomas were observed in 23.3% (49/210) of women exposed to hormonal therapy compared to 13.2% (87/659) of women not exposed to hormonal therapy (p < 0.0001). Women taking ethinyl estradiol/norethindrone (Lo-Estrin), leuprolide, and medroxyprogesterone were significantly more likely to have apoplectic leiomyomas compared to women taking other hormonal therapies. Apoplectic leiomyomas were observed in 28.9% (44/152) of African-American women compared to 12.4% (79/639) of Caucasian women (p < 0.0001), and this difference remained statistically significant regardless of hormone use. Apoplectic leiomyomas were observed in 22.1% (77/349) of women ≤ 45 years of age compared to 11.3% (59/520) of women > 45 years of age (p < 0.0001), and this difference remained statistically significant regardless of hormone use.This is the largest study to date examining apoplectic leiomyomas in women on known hormonal therapy compared to women with uterine leiomyomas, but not on hormonal therapy. Information about hormonal therapy, ethnicity, and age can be helpful in the diagnostic interpretation of apoplectic leiomyoma.

Myxoid leiomyosarcoma of the uterus.

AIMS: Recent guidelines have suggested the presence of tumour cell necrosis (TCN), atypia and mitotic index as major features in the distinction of myxoid leiomyosarcomas (MLMSs) from myxoid leiomyomas. The aim of this study was to focus on an invasive growth pattern as a significant feature in this distinction in the absence of TCN. METHODS AND RESULTS: Twelve uterine smooth muscle tumours with myxoid change in ≥60% of the lesion were interpreted as MLMS on the basis of the presence of focal mild atypia as well as one or more of the following features: (i) infiltrative growth pattern; (ii) vascular invasion; (iii) mitotic index of ≥5 mitotic figures (m.f.)/50 high-power fields (HPFs); and (iv) a combination of at least focal severe atypia and at least 2-4 m.f./50 HPFs. Unequivocal TCN was not evident in any of these tumours. The various morphological features were correlated with outcome. With follow-ups ranging from 19 to 113 months (mean 60 months), five of the 12 women developed recurrences, and two of them died. Nine of the 12 tumours had an infiltrative growth pattern, and all five recurrent tumours were from this group. CONCLUSION: In the absence of TCN, an infiltrative margin is a major factor related to the potential for aggressive behaviour of MLMS.

Chromosomal aberrations as detected by array comparative genomic hybridization in early low-grade intraepithelial neoplasias of the breast.

AIMS: Low-grade flat ductal intraepithelial neoplasia (DIN1a, flat epithelial atypia) is one of the earliest morphologically recognizable neoplastic lesions of the breast. Frequently, it occurs concomitantly with lobular intraepithelial neoplasia (LIN). We aimed to elucidate chromosomal aberrations in these early neoplastic breast lesions with the use of array comparative genomic hybridization analysis. METHODS AND RESULTS: Laser capture microdissection of 12 archival formalin-fixed, paraffin-embedded specimens harbouring foci of both DIN1a and LIN was performed. All analysed cases of DIN1a and LIN showed chromosomal gains and losses. The aberration encountered most often was loss of 16q, noted in seven DIN1a (70% of those successfully examined) and 10 LIN (91%) cases. The next most common alteration was a gain on 1q, noted in four DIN1a (40%) and seven LIN (64%) cases. CONCLUSIONS: The results show concurrent chromosomal aberrations of 1q gains and 16q losses in several cases with coexisting LIN and DIN1a. These aberrations are known to be common in low-grade invasive (ductal and lobular) carcinomas as well as in more advanced (conventional) types of low-grade ductal intraepithelial neoplasia (DIN) (low-grade ductal carcinoma in situ). Our results raise the possibility of similar molecular-genetic pathways in coexisting LIN and low-grade flat DIN.

Positioning of necrotic lobular intraepithelial neoplasias (LIN, grade 3) within the sequence of breast carcinoma progression.

Lobular intraepithelial neoplasia Grade 3 (LIN3) is a recently recognized variant of intraepithelial lobular neoplasia (LIN) of the breast composed of either uniform, generally small cells with massive lobular distension, pleomorphic cells, signet-ring cells, or any cell type with necrosis. In contrast to classic forms of LIN, there is no consensus on therapeutic strategies for LIN3. In part this is due to the paucity of molecular data that could assist in defining the relationship of LIN3 to classic LIN and carcinomas. In this study we have employed array comparative genomic hybridization to determine the patterns of chromosomal aberrations in nine LIN3 lesions. By comparison to array CGH data of 13 classic LIN lesions, we demonstrate that classic LIN and LIN3 share several recurrent changes, in particular gains of 1q and losses of 16q. Both aberrations are known to appear early in tumorigenesis and to be associated with good prognosis. However, apart from this overlap, there were a number of karyotypic features that were observed exclusively in LIN3. Clearly, this lesion was characterized by a significantly higher number of DNA copy number changes (9 vs. 31 on average), a considerable complexity of chromosomal rearrangements with more than 16 breakpoints in one chromosome and overlapping high copy amplifications encompassing a number of known oncogenes. Our data suggest that, at the genetic level, LIN3 represents a highly advanced lesion with considerable resemblance to carcinomas and, therefore, might represent the transition state from an intraepithelial neoplasm to breast carcinoma.

Preoperative chemotherapy decreases the need for re-excision of breast cancers between 2 and 4 cm diameter.

INTRODUCTION: It is accepted that preoperative chemotherapy can result in increased breast preservation for breast cancers greater than 4 cm. The benefits of preoperative chemotherapy are less clear, however, for patients who present with smaller tumors and are already candidates for breast-preserving surgery. The goal of this study is to assess the effect of preoperative chemotherapy on breast cancers between 2 and 4 cm diameter. METHODS: A retrospective chart review was conducted of patients diagnosed with new breast cancer at the Yale-New Haven Breast Center for the years 2002-2007. Patients were included in the study if their breast cancer was between 2 and 4 cm and their initial surgical treatment had been completed. Patients with distant metastases were excluded. RESULTS: There were 156 new cancers that met study requirements. Forty-seven patients underwent preoperative chemotherapy, and 109 patients had their surgery first, usually followed by chemotherapy. Initial surgery was lumpectomy for 31 out of 47 patients (66%) in the preoperative chemotherapy group compared with 62 out of 109 patients (57%) in the surgery group. For patients with lumpectomies, 2 out of 31 patients (6%) in the preoperative group had positive margins and required re-excision compared with 20 out of 62 patients (37%) in the surgery-first group (P<0.01). CONCLUSIONS: We conclude that, for tumors between 2 and 4 cm, preoperative chemotherapy is associated with a significantly decreased rate of re-excision following lumpectomy. This not only results in fewer mastectomies, but also avoids the morbidity and inferior cosmetic results associated with a re-excision lumpectomy.

Comparative analysis of P16 and P53 expression in uterine malignant mixed mullerian tumors.

Recent studies have shown that, in addition to cervical carcinomas, a substantial proportion of endometrial adenocarcinomas are also immunoreactive with p16. The expression of p16 in uterine malignant mixed mullerian tumors (MMMTs), in contrast, has not yet been analyzed in a large series. To our knowledge, we present the first study assessing p16 expression in both components of MMMTs. We performed p16 and p53 immunostains on 30 cases of uterine MMMTs. Both the epithelial and mesenchymal components were subclassified; p16 and p53 immunoreactions were assessed using a semiquantitative scoring system. p16 overexpression was noted in the carcinomatous component in 96.7% (29/30), and in the sarcomatous component in 86.7% (26/30) of cases. In comparison, p53 immunoreactivity was present in the carcinomatous component in 76.7% (23/30), and in the sarcomatous component in 83.3% (25/30) of cases. p16 immunoreactivity was more intense and diffuse than p53 in 40% of type I, 30% of type II carcinomas, and 27% of sarcomatous components. There was no significant difference in p16 or p53 immunoreactivity between the homologous and heterologous sarcomas. The concordance rates for p16 and p53 immunoreactivity between the 2 components were 83% and 90%, respectively. We conclude that p16 immunostain is positive in the vast majority of uterine MMMTs with no significant difference in staining between the 2 components. Compared with p53, p16 immunoreactivity is significantly more intense and diffuse in both components. Our findings indicate that alterations in the p16-Rb pathway play an important role in the pathogenesis of uterine MMMTs.

Complementary value of the Ki-67 proliferation index to the oncotype DX recurrence score.

Oncotype DX is a 21-gene assay that quantifies the recurrence risk in estrogen receptor-positive breast cancer, which is expressed as the recurrence score (RS). Studies have shown that patients with a high-risk RS will most likely benefit from adjuvant chemotherapy, but there is no proven advantage for patients with a low-risk RS who still face an average recurrence risk of 7%. In this study, the relationship between the RS and the cell cycle-related antigen Ki-67 was assessed in 32 breast carcinomas and evaluated for a potential association. Comparison of the RS with tumor type, grade, and the Ki-67 proliferation index (PI) revealed an overall concordance. However, some tumors with a low RS revealed a surprisingly high Ki-67 PI. These cases may correspond to the 7% of low-risk RS carcinomas that recur. Therefore, the authors propose a combined evaluation of the RS and Ki-67 PI to identify tumors with high recurrence potential from the low-risk and intermediate-risk RS groups.

Clinical and pathologic aspects of basal-like breast cancers.

Gene-expression profiling of breast cancers has shown that distinct molecular subclasses are present within tumors that are apparently morphologically similar. The molecular subclasses of cohorts classified by the 'intrinsic' gene set include the luminal A and B, erbB-2+, normal-breast-like, and basal-like tumors. Basal-like breast cancers have been reported to be associated with worse overall and disease-free survival compared with the luminal A subtype. In addition, there is an immunohistochemical surrogate for the basal-like profile, which has considerably facilitated their study in non-specialty laboratories. Basal-like breast carcinomas have markedly reduced expression of genes related to estrogen receptors and erbB-2, and express proteins that are characteristic of the normal myoepithelial cell. This Review appraises the current state of knowledge on the clinical and pathologic features of breast cancers classified as 'basal-like' by gene-expression profiling and/or immunohistochemical criteria. These tumors seem to be relatively heterogeneous according to a multitude of clinicopathologic parameters, which indicates that their most prognostically relevant subsets have yet to be defined. Similarly to tumors of luminal epithelial differentiation, carcinomas of the 'basal' type have a spectrum of morphologic and clinical characteristics.

HER2 in well differentiated breast cancer: is testing necessary?

BACKGROUND: In addition to providing a timely and accurate diagnosis, pathologists routinely provide prognostic and predictive information to assist in the treatment of patients with invasive breast cancer. As our understanding of breast cancer at the molecular and genetic level improves, sophisticated new treatment options have become available to patients. The demonstrated improvements in disease-free and overall survival with the use of trastuzumab (Herceptin) has made HER2 testing a standard of care in the evaluation of patients with breast cancer. Specialized breast centers have accumulated sufficient experience to recognize that HER2 positive tumors tend to be of higher grade and to be estrogen receptor negative, whereas well-differentiated breast cancers rarely are HER2 positive. METHODS: To determine whether HER2 testing is necessary in well-differentiated breast cancer, we analyzed the frequency of HER2 positivity among 1,162 cases from 7 major breast centers or commercial laboratories in the United States and Europe. RESULTS: Well-differentiated breast cancers, defined by either nuclear grading or the Scarff-Bloom-Richardson system, rarely are HER2 positive (mean 1.6%, range 0-2.8%). CONCLUSIONS: Given the low rate of well differentiated HER2 positive tumors, falling within the range reported for false negative IHC tests for HER2, and the absence of published data demonstrating a beneficial effect of trastuzumab therapy in this subset of patients, HER2 testing should not be considered a standard of care for all patients with well-differentiated breast cancer.

Frequency of clinically occult intraepithelial and invasive neoplasia in reduction mammoplasty specimens: a study of 516 cases.

Reduction mammoplasty is a frequently performed procedure for the treatment of macromastia and for the achievement of symmetry in breast cancer patients following lumpectomy. Slides from 516 consecutive bilateral reduction mammoplasties performed for macromastia over 15 years were reviewed. Among these, 92 (18%) low-risk ductal intraepithelial neoplasia/intraductal hyperplasia, 28 (5%) ductal intraepithelial neoplasia 1 (1 low-grade ductal carcinoma in situ, 11 atypical intraductal hyperplasia, and 16 flat type), 17 (3%) lobular intraepithelial neoplasia, and 1 (0.2%) tubular carcinoma were identified. The patients were categorized into 3 age groups: <40 (n=352), 40 to 50 (n=107), and over 50 years (n=57); the frequency of the lesions increased with age. These data confirm the low frequency of clinically occult malignancies identified in reduction mammoplasty specimens and provide substantial information about the frequency of a variety of intraepithelial proliferations. Preoperative mammography, specimen orientation, and inking of margins with 1 color are advised when reduction mammoplasty is scheduled for women>or=40 years of age.

Flat DIN 1 (flat epithelial atypia) on core needle biopsy: 63 cases identified retrospectively among 1,751 core biopsies performed over an 8-year period (1992-1999).

Uniform management of flat DIN 1 (flat epithelial atypia) on core needle biopsy (CNB) concerning surgical excision or clinical follow-up are lacking. In a retrospective review of 1,751 CNB over an 8-year period, we found 63 cases with flat DIN 1 as the most advanced lesion; follow-up was available in 55 cases. Of the 63 patients, 24 had a subsequent biopsy for 15 days to 10 years after the initial CNB, an infiltrating carcinoma was found in nine (14.3%) patients, seven (11.1%) in the ipsilateral, and two (3.2%) in the contralateral breast. Five underwent an excisional biopsy of the ipsilateral breast within less than 3 months of the initial CNB; none had either an invasive or intraepithelial carcinoma. Based on our findings, we consider flat DIN 1 a marker of slightly increased risk for subsequent development of invasive breast carcinoma. When flat DIN 1 is found on CNB as the most advanced lesion after mammographic correlation, an excisional biopsy is not mandatory; however, close follow-up is advised with repeat mammograms for early detection of any clinically occult carcinoma in the vicinity of flat DIN 1 that may have been missed by the CNB.

Uterine sarcomas.

A wide variety of sarcomas occur in the uterus but two subtypes - leiomyosarcoma and endometrial stromal sarcoma - account for a majority of those more routinely encountered. Using the 2003 World Health Organization classification, this review focuses on six uterine sarcomas: endometrial stromal sarcoma, undifferentiated endometrial sarcoma, leiomyosarcoma, rhabomyosarcoma, angiosarcoma and liposarcoma. The epidemiological, clinical, pathological and molecular features are presented along with therapeutic approaches. Familiarity with molecular aspects of these tumors and application of novel technologies in their assessment should be encouraged as they may provide alternate therapies resulting in improved survival for the patient. Clinical information necessary for accurate diagnosis of these lesions is emphasised. A multidisciplinary approach to management of patients with uterine sarcomas is essential for optimal management.

Lobular intraepithelial neoplasia [lobular carcinoma in situ] with comedo-type necrosis: A clinicopathologic study of 18 cases.

The recent finding that lobular, and not ductal intraepithelial neoplasia (DIN) displays loss of E-cadherin expression has greatly facilitated the categorization of a large proportion of morphologically ambiguous intraepithelial neoplasias into ductal or lobular types. One reason for such morphologic ambiguity is the presence of comedo-type necrosis within an intraepithelial lesion that otherwise shows archetypal cytologic and architectural features of lobular intraepithelial neoplasia (LIN). The clinicopathologic features of 18 such cases are described in this report. These 18 cases of classic LIN were accumulated from the recent databases of 6 institutions. All cases, by definition, showed no expression of E-cadherin. The 18 patients, all women, were 41 to 85 years of age (mean 61.3). The lesions were initially identified in an excisional biopsy or mastectomy in 12 cases and in an incisional/core biopsy in the remaining 6 cases. An associated invasive carcinoma was present in 12 (67%) of 18 cases (7 classic lobular, 1 pleomorphic lobular, 1 ductal, 1 mixed lobular and ductal, 1 tubular, and 1 case with ductal and lobular carcinomas as separate foci). The average age of the 6 patients with pure LIN (ie, LIN without an invasive component (62.5 y) was not significantly different from the 12 patients in which there was an invasive component (60.7 y) (P = 0.78). The lesions had associated calcifications, typically within the necrotic foci, in 10 (55%) of 18 cases. Immunoreactivity for estrogen receptor, progesterone receptor (in >10% of lesional cells), and high-molecular weight keratin was present in 17/18 (94%), 15/18 (83%) and 17/18 (94%) of cases, respectively. Overexpression of HER2/neu, as assessed immunohistochemically, was absent in all 15 cases available for such evaluation. Foci of DIN, separate from the lobular lesions, were present in 6 (33%) of 18 cases. LIN with necrosis seems to occur at an older age than classic LIN, is commonly associated with invasive carcinoma and is significantly more frequently associated with lobular than ductal invasive carcinoma. When present without an invasive component, it may be mistaken for DIN 2 (grade 2 ductal carcinoma in situ). Although the necrosis suggests a ductal phenotype for these intraepithelial proliferations, architectural and cytologic features, high-molecular weight keratin[+], estrogen receptor[+], progesterone receptor[+], and human epidermal growth factor receptor 2 /neu[-] immunoprofile, frequent association with invasive lobular carcinoma, and lack of immunoreactivity for E-cadherin, strongly suggests that these lesions are within the morphologic spectrum of lobular neoplasia. Long-term follow-up studies are required to define the true natural history of these lesions. However, because classic LIN with necrosis is apparently rare in its pure form, reexcision is recommended when this lesion is detected in isolation in a core biopsy.

STAT 5a expression in the breast is maintained in secretory carcinoma, in contrast to other histologic types.

The 7 signal transducer and activator of transcription (STAT) molecules are responsible for the transcription of a variety of regulatory and differentiation proteins. STAT 5a is activated through a variety of mechanisms; in the breast, this is predominantly through binding of prolactin to its receptor. Previously, we showed that STAT 5a expression is decreased in atypical and malignant breast ductal epithelial cells. Interestingly, STAT 5a overexpression was observed in cells undergoing secretory change. In this study, secretory carcinomas were examined by immunohistochemistry for the presence of STAT 5a. In contrast to usual in situ or invasive ductal carcinoma, which lacked STAT 5a expression, all secretory carcinomas (11 invasive and 7 in situ, including 4 cases with both) expressed STAT 5a. No expression was seen in apocrine metaplasia or in other specialized breast carcinomas, such as mucinous or clear cell carcinoma. This retention of signal in the secretory carcinomas may be explained by the higher STAT 5a concentration present in cells undergoing secretory changes in general. Alternatively, STAT 5a expression may be related to the t(12;15)(p13;q25) chromosomal translocation, associated with certain pediatric tumors and recently demonstrated in many secretory carcinomas of the breast, which results in the expression of a tyrosine kinase through ETV6 and NTRK3 fusion. ETV6 also has been associated with the STAT 5a signaling pathway in another gene translocation and may be altering STAT 5a expression in secretory carcinomas. Breast cancer causes significant morbidity and mortality, and, regardless of the mechanism for retention of STAT 5a expression in this uncommon variant, the examination of STAT 5a will aid our understanding of normal and abnormal breast tissues.

Discrepancies in the diagnosis of intraductal proliferative lesions of the breast and its management implications: results of a multinational survey.

To measure discrepancies in diagnoses and recommendations impacting management of proliferative lesions of the breast, a questionnaire of five problem scenarios was distributed among over 300 practicing pathologists. Of the 230 respondents, 56.5% considered a partial cribriform proliferation within a duct adjacent to unequivocal ductal carcinoma in situ (DCIS) as atypical ductal hyperplasia (ADH), 37.7% of whom recommended reexcision if it were at a resection margin. Of the 43.5% who diagnosed the partially involved duct as DCIS, 28.0% would not recommend reexcision if the lesion were at a margin. When only five ducts had a partial cribriform proliferation, 35.7% considered it as DCIS, while if >or=20 ducts were so involved, this figure rose to 60.4%. When one duct with a complete cribriform pattern measured 0.5, 1.5, or 4 mm, a diagnosis of DCIS was made by 22.6, 31.3, and 94.8%, respectively. When multiple ducts with flat epithelial atypia were at a margin, 20.9% recommended reexcision. Much of these discrepancies arise from the artificial separation of ADH and low-grade DCIS and emphasize the need for combining these two under the umbrella designation of ductal intraepithelial neoplasia grade 1 (DIN 1) to diminish the impact of different terminologies applied to biologically similar lesions.