Ultrasound-based logistic regression model LR2 versus magnetic resonance imaging for discriminating between benign and malignant adnexal masses: a prospective study.

BACKGROUND: The diagnostic performances of the International Ovarian Tumor Analysis (IOTA) ultrasound-based logistic regression model (LR2) and magnetic resonance imaging (MRI) in discriminating between benign and malignant adnexal masses have not been directly compared in a single study. METHODS: Using the IOTA LR2 model and subjective interpretation of MRI findings by experienced radiologists, 265 consecutive patients with adnexal masses were preoperatively evaluated in two hospitals between February 2014 and December 2015. Definitive histological diagnosis of excised tissues was used as a gold standard. RESULTS: From the 265 study subjects, 54 (20.4%) tumors were histologically diagnosed as malignant (including 11 borderline and 3 metastatic tumors). Preoperative diagnoses of malignant tumors showed 91.7% total agreement between IOTA LR2 and MRI, with a kappa value of 0.77 [95% confidence interval (CI), 0.68-0.86]. Sensitivity of IOTA LR2 (0.94, 95% CI, 0.85-0.98) for predicting malignant tumors was similar to that of MRI (0.96, 95% CI, 0.87-0.99; P = 0.99), whereas specificity of IOTA LR2 (0.98, 95% CI, 0.95-0.99) was significantly higher than that of MRI (0.91, 95% CI, 0.87-0.95; P = 0.002). Combined IOTA LR2 and MRI results gave the greatest sensitivity (1.00, 95% CI, 0.93-1.00) and had similar specificity (0.91, 95% CI, 0.86-0.94) to MRI. CONCLUSIONS: The IOTA LR2 model had a similar sensitivity to MRI for discriminating between benign and malignant tumors and a higher specificity compared with MRI. Our findings suggest that the IOTA LR2 model, either alone or in conjunction with MRI, should be included in preoperative evaluation of adnexal masses.

Neurosphere formation enhances the neurogenic differentiation potential and migratory ability of umbilical cord-mesenchymal stromal cells.

BACKGROUND AIMS: The human umbilical cord (UC) is a rich source of mesenchymal stromal cells (MSCs), which have been reported to have multi-lineage potential. The objectives of this study were to investigate the characteristics and capacity of UC-MSC neurosphere formation and whether this event enhances the propensity of UC-MSCs to undergo neural differentiation. METHODS: UC-MSCs were collected by the improved explant method. UC-MSCs and neurosphere-forming UC-MSCs (UC-MSC-neurospheres) were induced to undergo neurogenic differentiation, the latter of which were induced by suspension culturing in the presence of epidermal growth factor and basic fibroblast growth factor. The differentiation and migratory capacities of the individual cultures were then compared on the basis of the expression of neural markers, as measured by immunocytochemistry, immunoblotting and quantitative real-time polymerase chain reaction and transwell assays, respectively. RESULTS: Both UC-MSCs and UC-MSC-neurospheres were capable of differentiating into neurogenic cells when cultured in neurogenic differentiation medium. However, pre-conditioned UC-MSC-neurospheres exhibited significantly higher expression of neural markers--including microtubule-associated protein (MAP2), MUSASHI1, glial fibrillary acidic protein (GFAP), and NESTIN--compared with those derived from UC-MSCs directly. Moreover, UC-MSC-neurospheres expressed significantly higher levels of the stemness markers NANOG, KLF4 and OCT4 than did UC-MSCs. Migration assays also revealed that both UC-MSCs and UC-MSC-neurospheres actively migrate toward glucose-depleted cells. CONCLUSIONS: Neurogenic differentiation potential probably is greater in UC-MSC-neurospheres than in UC-MSCs. Thus, UC-MSC-neurospheres may serve as a better source of cells for neurogenic regenerative medicine.

Serum- and xeno-free cryopreservation of human umbilical cord tissue as mesenchymal stromal cell source.

BACKGROUND AIMS: Human umbilical cord (UC) has become a notable source for mesenchymal stromal cells (MSCs) that can migrate to areas of inflammation and damaged tissue and can suppress excess immune reactions and to repair, respectively. Although UC is a solid tissue, there are several advantages, including repeatable uses from the same donor sample when needed and the possibility of future explorations for cells with unknown potential, if we could cryopreserve the UC as a living tissue material. However, because the cryoprotectants in the previous reports included animal- or allogeneic human-derived serum or no serum, the frozen-thawed UC-MSCs were inferior to fresh UC-MSCs in cell proliferation. The objective of this study was to find a suitable cryopreservation method of UC for clinical use. METHODS: The UC was cut in cross-section and incised longitudinally, immersed in the cryoprotectant and frozen slowly. Later, it was thawed and minced rapidly, and the fragments of UC were cultured by improved explant method. RESULTS: The highest yield of cells was obtained from frozen-thawed UC with serum- and xeno-free cryoprotectant, STEM-CELLBANKER, when compared with others. The cells derived from frozen-thawed UC stored in STEM-CELLBANKER expressed the phenotypes of MSCs, retained the immunosuppressive properties in allogeneic mixed lymphocyte reactions and the differentiation potentials (into adipocyte and chondrocytes) comparable to those derived from fresh UC. CONCLUSIONS: UC can be cryopreserved in serum- and xeno-free cryoprotectant as a living tissue while keeping its growth and functions equivalent to fresh UC. Our method is simple and feasible for clinical use.

[Fertility-sparing treatment for gynecologic cancer].

Japanese women bear children at a later age. Thus, fertility-sparing treatment for gynecologic cancer is very important. Per the Japanese treatment guidelines for cervical cancer, the uterus can be preserved by performing cervical conization alone in patients with stage I A1 disease. Radical trachelectomy (RT) is not yet recommended for patients with stage I A2 or I B 1 disease in Japan. Further, RT will not be popular in Japan because cervical cancer can be prevented with HPV vaccine. The efficacy of fertility-sparing treatment with a high-dose of medroxyprogesterone acetate for grade 1 endometrial cancer was proven in a Japan clinical oncology group (JCOG) phase II study. Japanese multi-institutional retrospective investigation data confirm that fertility-sparing surgery is safe for patients with stage I A disease with non-clear cell histology grade 1 or 2. These data suggest that patients with stage I A disease with clear cell histology and those with stage I C disease with non-clear cell histology grade 1 or 2 can be candidates for fertility sparing surgery followed by adjuvant chemotherapy.

[A Patient with Recurrent Ovarian Cancer Who Was Hypersensitive to Carboplatin Exhibited Complete Response to Gemcitabine and Nedaplatin].

A 57-year-old multiparous woman with FIGO stage IV ovarian cancer underwent primary surgery and was administered postoperative chemotherapy consisting of paclitaxel and carboplatin (TC). Complete response was confirmed on computed tomography. After a 20-month platinum free interval (PFI), an elevated serum CA125 level and recurrence in the peritoneum were confirmed, and she was retreated with TC as second-line chemotherapy. A hypersensitivity reaction occurred after administering the second dose of carboplatin; therefore, carboplatin was changed to nedaplatin. Complete response was confirmed on computed tomography, and the serum CA125 level returned to normal. After an 8-month PFI, an elevated serum CA125 level and recurrence in the peritoneum and liver were confirmed, and she was treated with 6 cycles of combination chemotherapy consisting of gemcitabine (1,000 mg/m2: day 1 and 8 q3 weeks)and nedaplatin (80 mg/m2: day 1 q3 weeks). Only cytopenia (grade 2: CTCAE v4.0) was noted as a complication during chemotherapy. Complete response was confirmed on computed tomography. This report presents the case of a patient with recurrent ovarian cancer who was platinum sensitive and successfully treated with gemcitabine and nedaplatin after showing a hypersensitivity reaction to carboplatin.

Human papillomavirus genotype distribution in cervical intraepithelial neoplasia grade 2/3 and invasive cervical cancer in Japanese women.

OBJECTIVE: Human papillomavirus vaccines are being introduced worldwide and are expected to reduce the incidence of cervical cancer. Here we report a cross-sectional study using a validated human papillomavirus genotyping method to reveal the human papillomavirus prevalence and genotype distribution in Japanese women with cervical intraepithelial neoplasia Grade 2/3 and invasive cervical cancer. METHODS: Cervical exfoliated cells were collected from 647 patients with abnormal cervical histology (cervical intraepithelial neoplasia Grade 2, n = 164; cervical intraepithelial neoplasia Grade 3, n = 334; and invasive cervical cancer, n = 149), and subjected to the PGMY-PCR-based genotyping assay. The association between human papillomavirus infection and lesion severity was calculated using a prevalence ratio. RESULTS: Overall, the prevalence of human papillomavirus deoxyribonucleic acid was 96.3% in cervical intraepithelial neoplasia Grade 2, 98.8% in cervical intraepithelial neoplasia Grade 3 and 88.0% in invasive cervical cancer (97.8% in squamous cell carcinoma and 71.4% in adenocarcinoma). The three most prevalent types were as follows: human papillomavirus 16 (29.3%), human papillomavirus 52 (27.4%) and human papillomavirus 58 (22.0%) in cervical intraepithelial neoplasia Grade 2; human papillomavirus 16 (44.9%), human papillomavirus 52 (26.0%) and human papillomavirus 58 (17.4%) in cervical intraepithelial neoplasia Grade 3; and human papillomavirus 16 (47.7%), human papillomavirus 18 (23.5%) and human papillomavirus 52 (8.7%) in invasive cervical cancer. The prevalence ratio of human papillomavirus 16 was significantly higher in cervical intraepithelial neoplasia Grade 3 compared with cervical intraepithelial neoplasia Grade 2 (prevalence ratio, 1.62; 95% confidence interval, 1.26-2.13) and in squamous cell carcinoma compared with cervical intraepithelial neoplasia Grade 3 (prevalence ratio, 1.55; 95% confidence interval, 1.25-1.87). Multiple infections decreased from cervical intraepithelial neoplasia Grade 2/3 (38.4/29.6%) to invasive cervical cancer (14.1%), whereas co-infections with human papillomavirus 16/52/58 were found in cervical intraepithelial neoplasia Grade 2/3. CONCLUSIONS: The results of this study provide pre-vaccination era baseline data on human papillomavirus type distribution in Japanese women and serve as a reliable basis for monitoring the future impact of human papillomavirus vaccination in Japan.

[A case of stage IVb vulvar cancer effectively treated by concurrent chemoradiotherapy with cisplatin].

A 72-year-old woman was hospitalized because of a 10 cm tumor in her right inguinal area. Furthermore, a 6 cm tumor mass was observed in her right vulva. Computed tomography revealed multiple swollen lymph nodes in the para-aortic and pelvic areas. On the basis of these findings, the patient was diagnosed with stage IVb squamous cell carcinoma of the vulva. Radiation therapy of 67.4 Gy/33 Fr was administered to the pelvis, inguinal area and vulva. Four courses of chemotherapy with cisplatin (40 mg/m(2)) were concurrently administered every week during radiation therapy. The response to chemoradiotherapy was assessed to be complete. The patient has been doing well without any recurrence for 24 months.

MRI of endometriotic cysts in association with ovarian carcinoma.

OBJECTIVE: Although mural nodules are considered to be the most important hallmark in the recognition of ovarian cancers accompanied with endometriotic cysts, benign neoplasms and even inflammatory diseases can show similar MRI findings. We sought to clarify the MRI characteristics of malignancy accompanied with endometriotic cysts of the ovary. MATERIALS AND METHODS: Contrast-enhanced MRI was performed and endometriosis was pathologically confirmed in 49 patients with endometriotic cysts displaying mural nodules. Malignancy was pathologically diagnosed in 33 patients and benignity, in 16. Clinical data including patient age and MRI findings in terms of the size of the endometriotic cysts, number of loculi, presence of shading of the cysts, size of the mural nodules, signal intensity of the mural nodules on T1- and T2-weighted images, and contrast enhancement of the mural nodules were retrospectively reviewed. Statistical analysis of each parameter used the Mann-Whitney U test. RESULTS: The mean age of the patients and mean size of the endometriotic cysts were significantly higher in patients with a malignant condition than in those with a benign condition. Contrast enhancement of the mural nodules was observed in 97% of malignant and 44% of benign tumors. The size of the mural nodules was significantly larger in patients with a malignant condition than in those with a benign condition. Differences in size between the bilateral diseases, multilocularity, existence of shading, and the signal intensities of mural nodules were not significantly different between the malignant and benign conditions. CONCLUSION: Endometriotic cysts with enhanced mural nodules are not always complicated with malignancy. In elderly patients, the presence of large enhanced nodules on large endometriotic cysts is more likely to indicate malignancy.

Comparison of ThinPrep Integrated Imager-Assisted Screening versus Manual Screening of ThinPrep Liquid-Based Cytology Specimens.

OBJECTIVE: The aim of this study was to find out whether ThinPrep Integrated Imager (Hologic Inc.) screening is non-inferior to manual screening in the detection of cervical lesion. STUDY DESIGN: For a total of 4,011 ThinPrep Pap test specimens stained by ThinPrep staining, manual screening (Manual arm) and ThinPrep Integrated Imager screening (Imager arm) were performed so as not to be screened by the same cytotechnologist, and the sensitivity and specificity in the detection of cervical lesion were compared using McNemar's test. RESULTS: The sensitivity to detect CIN1 or more squamous cell abnormalities or glandular abnormalities was 91.67% (= 374/408, 95% confidence interval [CI]: 88.44-94.08%) for the Manual arm and 92.40% (= 377/408, 95% CI: 89.28-94.70%) for the Imager arm, and the specificity was 88.87% (= 3,113/3,503, 95% CI: 87.77-89.88%) for the Manual arm and 89.55% (= 3,137/3,503, 95% CI: 88.48-90.54%) for the Imager arm. The differences in sensitivity and in specificity, respectively, were 0.74% (95% CI: -3.14-4.61%, McNemar's test, p = 0.8041) and 0.69% (95% CI: -0.13-1.50%, McNemar's test, p = 0.1125). About the equality of sensitivity and specificity between the 2 methods, 95% CIs of the difference between sensitivity and specificity are in the clinical equivalence range of ±5%, so the Imager arm is non-inferior to the Manual arm. CONCLUSION: The Imager arm was confirmed to have an equivalent and non-inferior capacity in the detection of cervical lesions compared with the Manual arm, suggesting that its practical application in cervical cytology tests is highly possible.

Colon Metastasis From Microscopic Serous Carcinoma of the Fallopian Tube Fimbria Mimicking a Primary Colon Cancer.

Metastatic diseases rarely develop in the colorectum, and diagnosing colorectal metastasis by biopsy without history of a malignant tumor or clinical information of a primary tumor is challenging. A 65-year-old woman with a 6-month history of constipation and diarrhea was admitted to our hospital and diagnosed with rectosigmoid colonic micropapillary carcinoma. Low anterior resection was performed after neoadjuvant chemotherapy. Because the lipoleiomyoma in the uterus obstructed the operator's vision, total hysterectomy and bilateral salpingo-oophorectomy were performed. Examination of the colon and adnexa, together with immunohistochemical studies, revealed that the colonic tumor was actually serous carcinoma that had metastasized from the left fimbria of the fallopian tube. Retrospective immunohistochemical examination of the colon biopsy specimen suggested carcinoma with a Müllerian immunophenotype. When a colon biopsy reveals carcinoma with an invasive micropapillary pattern without a component of conventional tubular adenocarcinoma, immunohistochemical examination should be performed to rule out the possibility of metastasis.

Pulmonary Metastasis of Undifferentiated Uterine Sarcoma Forming Fluid-Containing Cyst.

Undifferentiated uterine sarcoma (UUS) is a high-grade sarcoma with no specific differentiation; however, it exhibits variable positivity for CD10 as an immunohistochemical marker of endometrial stroma, suggesting immunohistochemical differentiation into endometrial stroma. It has been reported that some low-grade endometrial stromal sarcoma pulmonary metastatic foci show cystic changes; however, whether pulmonary metastatic UUS foci are solid or cystic remains undescribed. A 63-year-old woman underwent a hysterectomy. The subsequent pathologic diagnosis was UUS. After the operation, she was treated with chemotherapy; however, pulmonary solitary shadow was radiologically detected. Eight months after the gynecologic operation, her pulmonary lesion was surgically resected. Pathologically, the lesion consisted of a cyst containing serous fluid with thick whitish wall composed of tumor cells, which led to the diagnosis of metastatsis of UUS. The cyst seemed to be formed via secondary degeneration. She remains healthy without recurrence 28 months after her first visit to our hospital.

MR findings of ovarian tumors with hormonal activity, with emphasis on tumors other than sex cord-stromal tumors.

Sex cord-stromal tumors including granulosa cell tumor, thecoma, Sertoli stromal cell tumor and steroid cell tumor are noted for their hormonal activity. However, there are many kinds of ovarian tumors other than sex cord-stromal tumors and tumor-like conditions with endocrine manifestations. Cross-sectional imaging, especially MR, can provide precise features of ovarian tumors and uterine morphological change even in a clinically latent excess of estrogen. In this article, we demonstrate typical imaging findings of ovarian tumors with hormonal activity. We also shortly explain the mechanism of the virilization and hyperestrogenism caused by ovarian tumors and tumor-like conditions.

Explanation for the failure of neoadjuvant chemotherapy to improve outcomes after radiotherapy for locally advanced uterine cervical cancer from the standpoint of the tumor regression rate.

PURPOSE: Treatment outcomes for patients with locally advanced cervical cancer are no better with neoadjuvant chemotherapy (NAC) combined with radiotherapy (RT) than with RT alone. We investigated the reason for this failure from the standpoint of the tumor regression rate (RR). MATERIALS AND METHODS: A total of 48 patients with clinical stage IIB-IVA cervical squamous cell carcinoma were treated clinically with cisplatin-based NAC plus RT (n = 15) or RT alone (n = 33). The RR was defined as the slope of a tumor shrinkage curve derived with magnetic resonance images. The local control rate (LCR) and disease-free rate (DFR) were estimated by clinical stage (IIB vs. III-IVA), pretreatment volume (< or = median vs. > median), lymph node status (negative vs. positive), treatment type, overall treatment time (< or =8 weeks vs. >8 weeks), and RR (< or = median vs. > median) using univariate and multivariate analyses. RESULTS: RR during NAC or during NAC and RT (n = 15) was not significantly higher than RR by RT alone (n = 33). Low RR and positive nodal status were significantly powerful prognostic factors for both the LCR and DFR, whereas the others were not. CONCLUSION: Although effective in reducing tumor volume prior to RT, NAC showed no overall effect in increasing the RR, which was shown to be the most powerful prognostic factor.

Magnetic resonance findings of primary uterine malignant lymphoma.

To clarify the magnetic resonance (MR) characteristics of primary uterine malignant lymphoma, we identified 4 patients with primary uterine lymphoma in the MR database of our institute from 1994 to 2005 and evaluated their clinical and MR findings for tumor extension, size, shape, and signal intensity, multinodular growth pattern, preservation of normal endometrium, and lymphadenopathy. In all 4 patients, tumors extended to the uterus and vagina or parametrium, and uterine tumors showed relatively homogeneous intensity on both T(1)- and T(2)-weighted MR imaging. Two patients showed multinodular tumor growth; three revealed pelvic lymphadenopathy; and none had intact endometrium or normal uterine zonal structure. Thus, large tumors with relatively homogeneous signal intensity seemed to be a specific MR finding of uterine lymphoma, and findings of multinodular growth were considered a possible characteristic suggesting the uterine involvement of malignant lymphoma.

Two cases of adenocarcinoma in situ arising in lobular endocervical glandular hyperplasia indicating localization of mucin on the cluster surface as an early cytological finding of malignant transformation.

Lobular endocervical glandular hyperplasia (LEGH) is an endocervical glandular hyperplastic lesion containing pyloric gland-like mucin, and has recently been recognized as a precursor lesion of malignant glandular lesions of the endocervix. The pyloric gland-like mucin contained in LEGH and gastric-type adenocarcinoma is observed as golden-yellowish by Papanicolaou staining. However, to our knowledge, the chronological course of the endocervical cytology of LEGH, eventually resulting in malignancy, has never been demonstrated to date. Here, we report two cases of gastric-type adenocarcinoma in situ (AIS) arising in LEGH, together with an analysis of their cytological course. In both cases, localization of mucin on the surface of glandular cell clusters was observed prior to nuclear atypia in endocervical cytology. In addition, the diagnosis of gastric-type AIS arising in LEGH was confirmed by pathological diagnosis of hysterectomy specimens in both cases. Histologically, all glandular cells of the LEGH without nuclear atypia contained a large amount of PAS-positive mucin. On the other hand, in atypical glandular cells, localization of the mucin on the luminal surface was observed, although mucin was abundant throughout the cytoplasm in some areas. Our cases show the course of acquirement of cytological atypia of LEGH, and indicate the significance of localization of mucin on the surface of glandular cell clusters as an early finding of the malignant transformation of LEGH in endocervical cytology. Our results indicate that the distribution of mucin in glandular cells should be analyzed together with nuclear atypia in the endocervical cytology of suspected cases of LEGH.

Intravenous injection of umbilical cord-derived mesenchymal stromal cells attenuates reactive gliosis and hypomyelination in a neonatal intraventricular hemorrhage model.

Intraventricular hemorrhage (IVH) is a frequent complication of preterm newborns, resulting in cerebral palsy and cognitive handicap as well as hypoxic ischemic encephalopathy and periventricular leukomalacia. In this study, we investigated the restorative effect on neonatal IVH by umbilical cord-derived mesenchymal stromal cells (UC-MSCs) cultured in serum-free medium (RM medium) for clinical application. UC-MSCs were cultured with αMEM medium supplemented with FBS or RM. A neonatal IVH mouse model at postnatal day 5 was generated by intraventricular injection of autologous blood, and mice were intravenously administered 1×105 UC-MSCs two days after IVH. Brain magnetic resonance imaging was performed at postnatal day 15, 22 and neurological behavioral measurements were performed at postnatal day 23, accompanied by histopathological analysis and cytokine bead assays in serum after IVH with or without UC-MSCs. Both UC-MSCs cultured with αMEM and RM met the criteria of MSCs and improved behavioral outcome of IVH mice. Moreover the RM group exhibited significant behavioral improvement compared to the control group. Histopathological analysis revealed UC-MSCs cultured with RM significantly attenuated periventricular reactive gliosis, hypomyelination, and periventricular cell death observed after IVH. Furthermore, human brain-derived neurotrophic factor and hepatocyte growth factor were elevated in the serum, cerebrospinal fluid and brain tissue of neonatal IVH model mice 24h after UC-MSCs administration. These results suggest UC-MSCs attenuate neonatal IVH by protecting gliosis and apoptosis of the injured brain, and intravenous injection of UC-MSCs cultured in RM may be feasible for neonatal IVH in clinic.

Early determination of uterine cervical squamous cell carcinoma radioresponse identifies high- and low-response tumors.

PURPOSE: To investigate whether early-assessed radioresponse of tumors corresponds with late-assessed radioresponse, which is associated with local disease control in radiotherapy (RT) for cervical cancer. METHODS AND MATERIALS: This prospective study included 12 patients with cervical squamous cell carcinoma treated by RT with or without concurrent cisplatin. Tumor volume was estimated by scheduled magnetic resonance imaging before (preRT), 3 to 4 weeks after (early assessment), and 6 to 7 weeks after (late assessment) RT initiation. Radioresponse was assessed with tumor shrinkage curves based on these volumes. Radioresponse for each tumor was calculated as the slope (day(-1)) of the shrinkage curve by fitting to an exponential equation. RESULTS: Early-assessed radioresponse ranged from 0.001 to 0.106 day(-1) (median, 0.021 day(-1)) and late-assessed radioresponse from 0.009 to 0.091 day(-1) (median, 0.021 day(-1)), with no significant difference between them (p = 0.1191). The early-assessed radioresponse correlated with the late-assessed radioresponse (R(2) = 0.714, p = 0.0005). CONCLUSIONS: Correspondence between early- and late-assessed radioresponse in a series of tumors showing a wide range of radioresponse was not particularly close overall. However, early assessment of radioresponsiveness did seem to be useful for characterizing those tumors with high or low radioresponsiveness.

A case of simultaneous bilateral spontaneous pneumothorax after the Nuss procedure.

We present a case of simultaneous bilateral spontaneous pneumothorax caused by a pleuro-pleural communication formed from Nuss procedure for pectus excavatum. A 17-year-old man with a history of Nuss operation complained chest pain and dyspnea. A chest roentgenogram demonstrated a tiny bilateral pneumothorax and two metallic bars inserted at the Nuss procedure. Computed tomography revealed furthermore a bulla in the apex of the left lung. The bilateral pneumothorax critically deteriorated after 4 days from onset and urgent bilateral chest drainages were performed. Nevertheless the drainages the full expansion of both lungs was not obtained and air leakage only from left side was continued. A video-assisted left bullectomy was performed 9 days after the tube insertion. The two bars penetrating anterior mediastinal pleura were thought to be a cause of the simultaneous bilateral spontaneous pneumothorax.

Microsatellite instability and expression of mismatch repair genes in sporadic endometrial cancer coexisting with colorectal or breast cancer.

The molecular background of sporadic endometrial cancer coexisting with colorectal or breast cancer is not clear. We investigated microsatellite instability (MSI) and status of mismatch repair (MMR) gene product, MLH1, MSH2 and MSH6, in 63 sporadic endometrial cancers coexisting with colorectal or breast cancer. Sixteen sporadic endometrial cancers with colorectal cancers (EC), 26 sporadic endometrial cancers with breast cancer (EB) and 21 endometrial cancers without a coexisting cancer (control) were analyzed. EC had the highest frequency of MSI among the 3 groups (EC, 69%; EB, 23%; and control, 43%). Incidence of low-frequency MSI was significantly higher in EC (38%). Among endometrial cancer cases diagnosed before age 50, all high-frequency MSI (MSI-H) cases belonged to EC. Interestingly, incidence of MSI-H was significantly higher in tamoxifen-non-treated cases (75%) than that of treated cases (14%). These results suggest that alterations in MMR genes appear to be involved in carcinogenesis of EC but seem to be uncommon in those of EB. Presence of MSI in sporadic endometrial cancer may be a useful marker to predict the risk of colorectal cancer.