Novel single-chain variant of antibody against mesothelin established by phage library.

Mesothelin (MSLN) shows increased expression in various cancer cells. For clinical application of antibodies as a positron emission tomography (PET) imaging reagent, a human shortened antibody is essential both for avoiding redundant immune responses and for providing rapid imaging. Therefore, we cloned a single-chain fragment of variable regions (scFv) from a human-derived gene sequence. This was achieved through the construction of a naïve phage library derived from human tonsil lymphocytes. Using a column with human recombinant MSLN, we carried out bio-panning of phage-variants by colony formation. We first obtained 120 clones that were subjected to selection in an ELISA using human recombinant MSLN as a solid phase antigen, and 15 phage clones of scFv with a different sequence were selected and investigated by flow cytometry (FCM). Then, six variants were selected and the individual scFv gene was synthesized in the VL and VH domains and expressed in Chinese hamster ovary cells. Mammalian cell-derived human-origin scFv clones were analyzed by FCM again, and one MSLN highly specific scFv clone was established. PET imaging by 89 Zr-labeled scFv was done in mice bearing xenografts with MSLN-expressing cancer cells, and tumor legions were successfully visualized. The scFv variant established in the present study may be potentially useful for cancer diagnosis by PET imaging.

Conclusive Evidence for OCT4 Transcription in Human Cancer Cell Lines: Possible Role of a Small OCT4-Positive Cancer Cell Population.

The role of octamer-binding transcription factor 4 (OCT4) in human cancer is still debated. Although many studies have been published on human OCT4, determining which of the findings are accurate or which are false-positives is currently challenging. We thus developed the most reliable method to date for highly specific and comprehensive detection of genuine OCT4-transcript variants without false-positive results. Our results provided clear evidence that the transcripts of OCT4A, OCT4B, OCT4B1, and other novel splicing variants are indeed present in many cancer cell lines, but are rarely detected in normal tissue-derived differentiated cells. Using the tagged genomic transgene, we then verified endogenous OCT4A translation in cancer cell subpopulations. Moreover, analysis of possible other protein isoforms by enforced expression of OCT4B variants showed that the B164 isoform, designated human OCT4C, is preferentially produced in a cap-dependent manner. We confirmed that the OCT4C isoform, similar to OCT4A, can transform non-tumorigenic fibroblasts in vitro. Finally, ablation of OCT4-positive cells using promoter-driven diphtheria toxin A in high malignant cancer cells caused a significant decrease in migration and Matrigel invasion. These findings strongly suggest a significant contribution of OCT4 to the phenotype of human cancer cells. Stem Cells 2018.

Morphological Analysis of Live Undifferentiated Cells Derived from Induced Pluripotent Stem Cells.

Induced pluripotent stem (iPS) cells possess pluripotency and self-renewal ability. Therefore, iPS cells are expected to be useful in regenerative medicine. However, iPS cells form malignant immature teratomas after transplantation into animals, even after differentiation induction. It has been suggested that undifferentiated cells expressing Nanog that remain after differentiation induction are responsible for teratoma formation. Various methods of removing these undifferentiated cells have therefore been investigated, but few methods involve morphological approaches, which may induce less cell damage. In addition, for cells derived from iPS cells to be applied in regenerative medicine, they must be alive. However, detailed morphological analysis of live undifferentiated cells has not been performed. For the above reasons, we assessed the morphological features of live undifferentiated cells remaining after differentiation induction as a basic investigation into the clinical application of iPS cells. As a result, live undifferentiated cells remaining after differentiation induction exhibited a round or oval cytoplasm about 12 µm in diameter and a nucleus. They exhibited nucleo-cytoplasmic (N/C) ratio of about 60% and eccentric nuclei, and they possessed partially granule-like structures in the cytoplasm and prominent nucleoli. Although they were similar to iPS cells, they were smaller than live iPS cells. Furthermore, very small cells were present among undifferentiated cells after differentiation induction. These results suggest that the removal of undifferentiated cells may be possible using the morphological features of live iPS cells and undifferentiated cells after differentiation induction. In addition, this study supports safe regenerative medicine using iPS cells.

Validation of 2 Prognostic Models in Hospitalized Patients With Advanced Hematological Malignancies in Japan.

Patients with advanced hematological malignancies are less likely to be referred to specialist palliative care services compared with patients having solid tumors. It has been reported that one of the most important reasons for the lack of referral is difficulties in the prognostication of terminally ill patients with hematologic malignancies. The study objective was to evaluate the predictive accuracy of the Palliative Prognostic Index (PPI) and the prognostic model developed by Kripp et al in hospitalized patients under the care of a hematologist. Using clinical charts, we retrospectively calculated the above scores. We reviewed the records of 114 patients admitted to the hematology ward. The inclusion criterion was patient with disease considered incurable using standard treatments. The prognostic models were assessed according to the original reports. Using PPI cutoff points of 2 and 4, we divided the patients into 3 groups of significantly different survival times ( P < .01). Moreover, we confirmed the usefulness of predicting survival <3 and <6 weeks using PPI scores of 6 and 4 as cutoff points, respectively. When we classified patients according to the prognostic model of Kripp et al, the high-risk group survived significantly shorter times than the intermediate- and low-risk groups ( P < .001). However, there was no significant difference in survival between the intermediate- and low-risk groups. Use of these models might enable physicians to provide more appropriate end-of-life care and to refer patients to palliative care earlier.

Isolation of side population cells from endometrial cancer cells using a violet laser diode.

Cancer stem cells (CSCs) possess the ability for self-renewal, differentiation, and tumorigenesis and play a role in cancer recurrence and metastasis. CSCs are usually sorted in analysis into side population (SP) cells using ultraviolet (UV) laser (350 nm) excitation; they cannot be stained with Hoechst 33342 because of their efflux ability. However, it is difficult to avoid cell damage using a UV laser. Therefore, we attempted to isolate CSCs using a violet laser (407 nm) excitation to avoid cellular DNA damage. We sorted SP cells and main population (MP) cells from a human endometrial cancer cell line using the FACSAria system equipped with a violet laser and analyzed the biological properties of these cells. SP cells exhibited drug efflux, self-renewal, differentiation abilities, and tumorigenicity. It was found that v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) expression was significantly higher in SP cells than in MP cells. Our results suggest that CSCs exist in the SP fraction sorted using the FACSAria system equipped with a violet laser, which presents a useful tool to isolate small populations of viable putative CSCs from solid tumors and can be used to identify and characterize CSCs.

Tumorigenesis in cells derived from induced pluripotent stem cells.

Induced pluripotent stem (iPS) cells are an attractive source for potential cell-replacement therapy. However, transplantation of differentiated products harbors the risk of teratoma formation, presenting a serious health risk. Thus, we characterized Nanog-expressing (undifferentiated) cells remaining after induction of differentiation by cytological examination. To induce differentiation of iPS cells, we generated embryoid bodies (EBs) derived from iPS cells carrying a Nanog­green fluorescent protein(GFP) reporter and then injected GFP-positive and GFP negative EBs into nude mice. GFP-positive EB transplantation resulted in the formation of immature teratoma grade 3, but no tumors were induced by GFP-negative EB. GFP positive cells revealed significantly lower cytoplasmic area and higher nucleus/cytoplasm ratio than those of GFP negative cells. Our results suggest that morphological analysis might be a useful method for distinguishing between tumorigenic and nontumorigenic iPS cells.

Diagnostic utility of notch-1 immunocytochemistry in endometrial cytology.

OBJECTIVE: It was the aim of this study to evaluate the diagnostic utility of Notch-1 immunocytochemistry in distinguishing endometrial glandular and stromal breakdown (EGBD) from endometrial adenocarcinoma in endometrial cytology. STUDY DESIGN: Samples of normal endometrium, EGBD and endometrial adenocarcinoma were subjected to immunocytochemical staining for Notch-1, and we examined the labeling index (LI) of Notch-1 (the ratio of intranuclear Notch-1-positive cells to total cells). We compared (1) the Notch-1 LI in normal endometrium, (2) the Notch-1 LI between normal endometrium and endometrial adenocarcinoma, and (3) the Notch-1 LI in normal endometrium, EGBD and endometrial adenocarcinoma. RESULTS: In analysis item 1, the LI of Notch-1 was 32.9 ± 8.4, 19.4 ± 8.2 and 12.5 ± 7.5% in proliferative endometrium, secretory endometrium and atrophic endometrium, respectively. In analysis item 2, the LI of Notch-1 in endometrial adenocarcinoma was 45.2 ± 7.4%, which was significantly higher than that in normal endometrium. In analysis item 3, the LI of Notch-1 in EGBD was 31.3 ± 8.3%, which was significantly lower than that in endometrial adenocarcinoma. CONCLUSION: In conclusion, Notch-1 immunocytochemistry is a useful method for distinguishing between EGBD and endometrial carcinoma in endometrial cytology.

Effects of N-[N-(3, 5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT) on cell proliferation and apoptosis in Ishikawa endometrial cancer cells.

Endometrial cancer is one of the most common gynecological malignancies in Japan, where the disease shows an increasing morbidity. However, surgical therapy remains the treatment of choice for endometrial cancers that tend to be insensitive to radiation therapy and chemotherapy. Therefore, novel therapeutic strategies are required. The Notch signaling pathway regulates embryogenesis and cellular development, but deregulated Notch signaling may contribute to tumorigenesis in several cancers. Moreover, γ-secretase inhibitors have been shown to be potent inhibitors of the Notch signaling pathway; they suppress cellular proliferation and induce apoptosis in several cancer cells. In the present study, we investigated the effect of N-[N-(3, 5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT, γ-secretase inhibitor) on the cell proliferation and apoptosis in Ishikawa endometrial cancer cells. Real-time PCR detected mRNA derived from NOTCH1 and HES1, which are target genes of the Notch signaling pathway, in Ishikawa endometrial cancer cells. After blocking Notch signaling, cellular proliferation decreased, accompanied by increased expression of p21 mRNA and decreased expression of the cyclin A protein. Furthermore, blockade of Notch signaling induced apoptosis. These results suggest that the Notch signaling pathway may be involved in cell proliferation through cell cycle regulation and apoptosis in Ishikawa endometrial cancer cells. Inhibition of the Notch signaling pathway by γ-secretase inhibitors is expected to be a potential target of novel therapeutic strategies for endometrial cancer.

Examination of CD26/DPPIV, p53, and PTEN expression in thyroid follicular adenoma.

Tumor cytology has proven to be inadequate for precise diagnosis of thyroid follicular adenoma. This suggests the need for a molecular approach for its diagnosis. Expression of CD26/DPPIV (dipeptidyl peptidas IV), p53, and PTEN was analyzed in smears or sections obtained from 19 patients with histologically proven thyroid follicular adenoma. Papanicolaou staining, CD26/DPPIV activity staining, and HE staining were performed and the specimens were observed morphologically. Immunohistochemical analysis using antibodies against p53 and PTEN was performed. Genetic mutation of PTEN exons was performed using the laser capture microdissection method. The nuclear area of the CD26/DPPIV-positive cells was significantly larger than that of the CD26/DPPIV-negative cells. p53 expression was not observed any specimen. PTEN expression was observed in 18 of 19 cases. DNA sequence analysis did not reveal mutations in exons 5-9 of PTEN in the immunohistochemically PTEN-negative case. In accordance with our previous reports, we found that observation of concomitant CD26-positive and PTEN-negative status in cases of follicular adenoma suggests a state close to follicular carcinoma or progression to cancer, thus warranting careful follow-up.

Cytologic appearance of myospherulosis of the breast diagnosed by fine-needle aspirates: a clinical, cytological and immunocytochemical study of 23 cases.

The objective of this study was to introduce the clinical and cytological aspects of myospherulosis. A total of 5,174 consecutive breast fine needle aspiration (FNA) cytology cases were reviewed, among which 23 cases of myospherulosis of the breast were found, all in female patients. The main findings of myospherulosis, best seen with the Papanicolaou stain, consisted in the observation of spherules that were homogeneously smooth or contained one or more internal dense bodies. Routine Papanicolaou-stained slides with or without Romanowsky staining were analyzed. Immunocytochemistry was conducted for carbonic anhydrase 1 (CA1), glycophorin C, KP1, and PGM1. The patients' ages ranged from 41 to 79 years (mean age: 56 years). Of the 23 patients, 21 had a previous history of breast surgery. Cytologically malignant or suspicious diagnoses were made in four of the 23 cases. The size of parent bodies varied from 18.2 to 151 µm (mean, 52 µm). The size of spherules ranged from 2.1 to 16.4 µm (mean, 6.6 µm). Immunocytochemistry showed that the myospherules reacted with anti-CA1 and anti-glycophorin C antibodies. Most breast myospheruloses occur in patients with a history of breast surgery. Immunocytochemistry for CA1 and glycophorin C can enhance the diagnosis of myospherulosis.

Improving the diagnostic accuracy of thyroid follicular neoplasms: cytological features in fine-needle aspiration cytology.

Cytological diagnosis in follicular neoplasms of the thyroid has to surmount some difficulties. Capsular/vascular invasions or metastasis are the histological criteria for follicular carcinoma (FC), and, on fine-needle aspiration (FNA) samples, marked cytological atypias are only observed in moderately to poorly differentiated FC, while they may be completely lacking in well differentiated angio- or capsulo-invasive FC. To clarify the cytological features and to improve the accuracy and reliability of aspiration cytology, 892 follicular adenomas and 82 FCs were reviewed. A macrofollicular pattern or large sheet pattern of follicular cells with thin colloid in the background were found to be indicators of follicular adenoma. Crowding or irregular arrangement of follicular cells were found to indicate microfollicular lesions but could not discriminate between benign and malignant conditions. High nucleo-cytoplasmic ratio, nuclear atypia, and coarse granular or dense chromatin were more important criteria for malignancy than nuclear grooves or intranuclear cytoplasmic inclusions. The cytomorphologic features of the follicular neoplasms of the thyroid are described, and the difficulties encountered in the cytodiagnosis of follicular lesions are discussed at length.

Three-dimensional reconstructive analysis of intracytoplasmic lumina found in ependymomas.

Three-dimensional reconstructive analyses revealed that the intracytoplasmic lumina found in ependymomas were actually formed by subsidence of an extracellular membrane, resembling a volcano. This finding was compatible with cytologic and electron microscopic findings. In addition, there were many tiny thorns resembling a holly leaf on the extracellular membrane, such that cilia and microvilli on the cellular membrane discontinued cell-to-cell tight junctions.

Expression of immunoreactivity and genetic mutation in eosinophilic and ciliated metaplastic changes of endometrial glandular and stromal breakdown: cytodiagnostic implications.

Various metaplastic changes may be present in endometrium, in which also cellular atypias may often be observed. Particularly, eosinophilic and ciliated changes (ECCs) occur in both nonneoplastic and neoplastic endometrium. This may cause confusion in the cytodiagnosis. This study was enterprised to investigate the possible help of immunocytochemical and cytogenetic study in the diagnostic and biologic assessment of ECC cells. In immunocytochemistry for p53 protein, Ki-67, and cyclin A, the material consists of 40 cases of cytologic smears examined by direct sampling of the endometrial cavity comprising 30 cases of ECC in endometrial glandular and stromal breakdown (EGBD) and 10 cases of well-differentiated adenocarcinoma (G1). After cytodiagnosis, immunostaining for p53 protein, Ki-67, and cyclin A was performed on multiple wet-fixed slides from each single case to evaluate the immunoreactivity, intensity of nuclear staining, and nuclear labeling index (N-LI). The intensity of nuclear staining was scored as negative (0), weak (1), moderate (2), or strong (3), and the N-LI was scored as less than 10% (0), from 10% to 25% (1), from 26% to 50% (2), or more than 50% (3), and the final score was calculated by adding both partial scores. A statistical significance test was performed by using Mann-Whitney U test, and the result was judged as significant when the P value was less than .05. For genetic mutation analysis of p53, the material comprised 6 cases of EGBD in which a high score was measured with immunocytochemistry for p53 protein, and the presence of ECC was confirmed on the hematoxylin and eosin. The ECC cells on paraffin-embedded specimens were captured using laser capture microdissection technology. Mutations in p53 gene (exons 5-8) were examined using DNA sequencing analysis. In immunocytochemistry for p53 protein, Ki-67, and cyclin A, the proportions of immunoreactive cells for p53 were statistically higher in ECC compared with those of G1 (P < .05). The proportions of the immunoreactive cells for Ki-67 and cyclin A were statistically higher in G1 compared with those of ECC (P < .05). (2) In genetic mutation analysis of p53, DNA sequencing of p53 in 6 cases revealed no mutations. The percentage of immunoreactive cells for p53 protein were higher in ECC than in G1, but the mutation point was not confirmed in genetic mutation analysis. The differential expression of these biologic parameters in ECC cells could be considered of possible relevance to the cytopathologic diagnosis in the future.

Mucinous breast carcinoma with myoepithelial-like spindle cells.

Appearance of spindle cells has been believed as a benign index of breast cytology. But, we have frequently observed the spindle cells in smears from mucinous carcinoma of the breast. Here, we characterized the biochemical nature of the spindle cells, so as to clarify their identity in cytology. Nineteen cases of breast mucinous carcinoma were used for cytological examination. The spindle cells were located at edges of tumor cell nests and in the backgrounds of cytological specimens. Immunohistological examination revealed that the spindle cells exhibited both immunoreactivity against carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Immunoreactivity against vimentin, cytokeratin, or alpha-smooth muscle actin was, however, not observed. The mode of distribution of biochemical markers suggests that the positive cells for anti-CEA antibody and anti-EMA antibody are tumor cells compressed by mucin, while the vimentin-positive cells are fibroblasts. We assert that the presence of spindle cells can be a characteristic feature of mucinous carcinoma of the breast. Discrimination of the spindle cells in mucinous carcinoma from myoepithelial cells and naked bipolar nuclei in benign lesions was established here. It should facilitate precise diagnosis of breast cancer.

Diagnostic value of endometrium associated with papillary metaplastic changes in endometrial cytopathology.

Papillary metaplastic changes especially occur in both non-neoplastic and neoplastic endometrium. We tried to investigate to assess the relationship between endometrial cytologic diagnosis and papillary metaplasia. The material consists of 160 cases of cytologic smears obtained by direct sampling of the endometrial cavity comprising 54 cases of normal proliferative endometrium (NPE), 36 cases of glandular and stromal breakdown (EGBD), and 70 cases of endometrial hyperplasia without atypia (EH). As for the correlation between the appearance of papillary metaplasia and cytological diagnosis, a statistical significance test was performed. The material consists of 40 cases of cytologic smears examined by direct sampling of the endometrial cavity comprising 10 cases of EGBD with papillary metaplasia, 10 cases of G1 without papillary metaplasia, 10 cases of NPE without papillary metaplasia, and 10 cases of EH without papillary metaplasia. Using the comparison between appearance of papillary metaplasia and cytological diagnosis, a significant difference was only seen in the rate of correct diagnoses in EGBD cases. The nuclear area of papillary metaplastic cells in EGBD was 888.8, G1 was 928.7, NPE was 682.0, and EH was 722.2. Significant difference was observed between ECC cells in EGBD to NPE, between papillary metaplastic cells in EGBD to EH, between G1 to NPE, or between G1 to EH. This study provides new and important information on the correlation between endometrial cytological diagnosis and papillary metaplastic changes.

Diagnostic utility of phosphatase and tensin homolog, beta-catenin, and p53 for endometrial carcinoma by thin-layer endometrial preparations.

BACKGROUND: For the current report, the authors examined the characteristic features of morphology and molecular biology of phosphatase and tensin homolog (PTEN), beta-catenin, and p53 immunocytochemistry in endometrial carcinoma by using thin-layer cytologic preparations. METHODS: During a 6-month period, 120 endometrial samples were collected directly by using the Uterobrush, and thin-layer specimens were prepared. Immunocytochemical expression levels of PTEN, beta-catenin, and p53 were investigated by using 40 specimens of endometrial carcinoma (EC), and 30 specimens each of proliferative endometrium, secretory endometrium, and atrophic endometrium. RESULTS: For PTEN immunoreactivity, the a cutoff value of 50% PTEN expression appeared to be useful for the correct diagnosis of EC in endometrial cytology. For beta-catenin immunoreactivity, an increase in cytoplasmic and nuclear beta-catenin expression and a loss of beta-catenin expression appeared to be useful for the correct diagnosis of EC in endometrial cytology and may aid in the stratification of EC into low grade and high grade EC. For p53 immunoreactivity, the application of a cutoff score >or=4 for nuclear p53 expression appeared to be useful for the diagnosis of high-grade EC in endometrial cytology. CONCLUSIONS: Immunocytochemical findings from a combination of PTEN, beta-catenin, and p53, in addition to cytomorphologic features, appeared to be useful for the more accurate diagnosis of EC in endometrial cytology.

Utility of thin-layer preparations in endometrial cytology: immunocytochemical expression of PTEN, beta-catenin and p53 for benign endometrial lesions.

This article focuses on the characteristic features of morphology and molecular biology of PTEN, beta-catenin, and p53 immunocytochemistry in normal endometrium (proliferative, secretory, and atrophic) and endometrial glandular and stromal breakdown (EGBD) using thin-layer specimens. During a 6-month period, 120 endometrial samples were collected directly using the Uterobrush and a thin-layer specimen was prepared. Immunocytochemical expression of PTEN, beta-catenin, and p53 were investigated using 30 cases each of proliferative endometrium (PE), secretory endometrium (SE), atrophic endometrium (AE), and EGBD.PTEN expression of normal endometrial glandular epithelial cells changes with the hormonal status; PE produce very high expression, SE creates attenuation or disappearance of PTEN expression and AE diminished more in comparison with SE. PTEN expression of EGBD showed a tendency towards attenuation compared with PE, but showed high expression in comparison with SE and AE. As for the immunoreactivity of beta-catenin, in all phases (PE, SE, AE, and EGBD), it was observed in the cytoplasm of glandular epithelial cells, but not nuclei, and showed strong membranous staining. As for the p53 immunoreactivity, p53 positivity was not observed in the glandular epithelial cells in all phases (PE, SE, AE, and EGBD) with the exception of some metaplastic cells. The presence of p53 immunoreactivity of a weak, low ratio in metaplastic cells was unexpected. In the current study, the expression manner of PTEN, beta-catenin, and p53 immunocytochemistry was observed in the normal endometrium (PE, SE, and AE) and EGBD.

Utility of thin-layer preparations in the endometrial cytology: evaluation of benign endometrial lesions.

The purpose of the current study was to examine the use of thin-layer cytologic (TLC) preparation compared to conventional cytologic preparation (CCP) in the normal endometrium (proliferative, secretory, atrophic) and endometrial glandular and stromal breakdown (EGBD). During a 6-month period, we compiled 158 cases by collecting a direct endometrial sample using the Uterobrush. The material comprised 40 cases of proliferative endometrium, 42 cases of secretory endometrium, 46 cases of atrophic endometrium, and 30 cases of EGBD. The following points were investigated: (1) number of endometrial epithelial cell clumps; (2) presence of TLC > CCP cases on number of epithelial cell clumps; (3) number of condensed cluster of stromal cells; (4) presence of TLC > CCP cases on number of condensed cluster of stromal cells; (5) presence of metaplastic clumps with irregular protrusion-containing condensed stromal cluster; (6) presence of a clear background; (7) presence of blood vessel in TLC; (8) presence of blood vessel of length more than diameter of a field in object x20 glasses in TLC. (1) In all phases, the number of epithelial cell clumps per a unit area of a preparation of TLC is greater than in CCP. (2) Cells (condensed cluster of stromal cells and metaplastic clumps with irregular protrusion-containing condensed stromal cluster) of useful and adequate numbers for a diagnosis of EGBD were observed in TLC. (3) In all phases, TLC was significantly higher than CCP on the appearance of a clear background. (4) The proliferative endometrium and secretory endometrium were highly significant in comparison with atrophic endometrium and EGBD, respectively, in terms of the occurrence of a blood vessel of length more than diameter of a field in object x20 glasses. Although the preparation area of TLC is smaller than that of CCP, the preparation has a clean background so that an accurate report on the patient's condition is possible. Therefore, TLC preparation is a useful tool for the accurate and reliable diagnosis of normal endometrial phase and EGBD, because the preparation area is confined and identification of the target cell clumps is easy.

Immunohistochemical expression of PTEN and beta-catenin for endometrial intraepithelial neoplasia in Japanese women.

PTEN and beta-catenin are the most common genes for which genetic abnormalities are found in endometrioid adenocarcinoma (type I) and even in their precursors. Currently, the World Health Organization (WHO) classifies endometrial hyperplasia as a premalignant disease. However, one of the problems in the current WHO endometrial hyperplasia schema is that it is not always a reproducible classification system. Subsequently, the alternative molecular genetics and morphometric-based classification, referred to as the endometrial intraepithelial neoplasia (EIN) classification system, has been proposed. We reclassified endometrial lesions in Japanese women using the EIN category and compared them with the results of PTEN as well as beta-catenin immunohistochemistry. A total of 117 cases that were initially diagnosed as endometrial hyperplasia according to WHO classification were reevaluated histopathologically by the EIN diagnosis category. They were classified into 38 EIN and 32 benign architectural changes of unopposed estrogen (BAC), and 47 cases were excluded. In addition, for comparison, we examined 20 cases of normal proliferative endometrium (NPE). Subsequently, the expressions of PTEN and beta-catenin were analyzed immunohistochemically. Glandular epithelium was positive for PTEN in all the cases of NPE (20/20), whereas 12.5% (4/32) of BAC and 34.2% (13/38) of EIN were PTEN-null (negative). Endometrial intraepithelial neoplasia was significantly less frequently positive for PTEN than NPE (P < .025). The nuclear staining for beta-catenin was seen in 26.3% (10/38) of EIN cases, and the intensity was generally strong. Instead, none of the BAC or NPE showed positive nuclear staining. Thus, the nuclear staining was statistically more frequently seen in EIN than in the other 2 categories (P < .025 for each). In addition, 22 of 38 EIN cases (57.9%) were either PTEN-negative or nuclear beta-catenin-positive. This combination was statistically significantly more frequently seen than BAC (4/32, 12.5%) (P < .001) and NPE (0/20, 0%) (P < .0001). Immunohistochemical loss of PTEN and positive nuclear staining of beta-catenin were frequently seen in EIN but were not seen in NPE cases in Japanese women. The combination of PTEN-negative/beta-catenin-positive results may become the reliable marker for detecting EIN.

Endometrial glandular and stromal breakdown, part 2: cytomorphology of papillary metaplastic changes.

Careful cytomorphologic evaluation of abnormal endometrial lesions has made accurate and reproducible microscopic assessment possible. Histopathology of patients with dysfunctional uterine bleeding due to an anovulatory cycle usually contain endometrial glandular and stromal breakdown (EGBD) and papillary metaplasia on the endometrial surface epithelium, if an appropriate sample has been collected. We often recognized abnormal cell clumps in the cytological smears with EGBD cases. They were composed of metaplastic cells, and some irregular small projection figures were observed from the margins of the cell clumps. We describe the quantitation of metaplastic clumps with irregular protrusions (MCIP) in endometrial endocyte samples. The current study presents the cytomorphological characteristics of the metaplastic changes recognized in EGBD cases. During a 7-yr period, 144 cases for which histopathological diagnoses were obtained following endometrial curettage, after collecting a direct endometrial sample using the endocyte. The material comprised 49 cases of normal proliferative endometrium (NPE) (patients aged 28-51, average 39.9), 32 cases of EGBD (patients aged 30-67, average 49.6), and 63 cases of endometrial hyperplasia without atypia (EH) (patients aged 35-65, average 47.7). The following points were investigated: (1) the occurrence of metaplastic cells; (2) the occurrence and the frequency of MCIP; and (3) the occurrence of MCIP that contains condensed stromal clusters. Metaplastic cells were seen in 93.8% of the EGBD cases. Cytomorphologic pattern identified with MCIP was 90.6%, and its frequency showed 16.1%. The occurrence of MCIP that contain condensed stromal clusters (93.1%) showed a strong association in comparison with other lesions, such as NPE and EH. Our data appear to indicate that the appearance of MCIP with condensed stromal clusters originated from the papillary metaplasia, which occurred on the endometrial surface epithelium. The cytologic observation of those cells may be a useful indicator for providing the nature of EGBD endometrium.