Constitutive Cytomorphologic Features of Medullary Thyroid Carcinoma Using Different Staining Methods.

(1) Background: Accurate preoperative identification of medullary thyroid carcinoma (MTC) is challenging due to a spectrum of cytomorphologic features. However, there is a scarcity of studies describing the cytomorphologic features as seen on fine-needle aspiration (FNA) smears prepared using different staining methods. (2) Methods: We performed a retrospective study on MTC cases with available FNA slides from 13 hospitals distributed across 8 Asia-Pacific countries. The differences in the constitutive cytomorphologic features of MTC with each cytopreparatory method were recorded. A comparative analysis of cytologic characteristics was carried out with appropriate statistical tests. (3) Results: Of a total of 167 MTC samples retrospectively recruited, 148 (88.6%) were interpreted as MTC/suspicious for MTC (S-MTC). The staining methods used were Papanicolaou, hematoxylin-eosin, and Romanowsky stains. Seven out of the eleven cytologic criteria can be readily recognized by all three cytopreparatory methods: high cellularity, cellular pleomorphism, plasmacytoid cells, round cells, dyshesive cells, salt-and-pepper chromatin, and binucleation or multinucleation. An accurate diagnosis was achieved in 125 (84.5%) of the 148 samples whose FNAs exhibited five or more atypical features. Conclusions: The present work is the first study on MTC to compare the morphological differences among the cytologic staining techniques. We investigated the constitutive features and the reliability of diagnostic parameters. A feasible scoring system based upon cytomorphologic data alone is proposed to achieve a high degree of diagnostic accuracy.

Extracellular vesicles activate ATM-Chk2 signaling pathway through the intercellular transfer of mitochondrial DNA in HBV-infected human hepatocytes.

Hepatitis B virus (HBV) is a human hepatotropic pathogen causing hepatocellular carcinoma. We recently obtained HBV-susceptible immortalized human hepatocyte NKNT-3 by exogenously expressing NTCP and its derived cell clones, #28.3.8 and #28.3.25.13 exhibiting different levels of HBV susceptibility. In the present study, we showed that HBV infection activated the ATM-Chk2 signaling pathway in #28.3.25.13 cells but not in #28.3.8 cells. Both the cell culture supernatant and extracellular vesicles (EVs) derived from HBV-infected #28.3.25.13 cells also activated the ATM-Chk2 signaling pathway in naïve #28.3.25.13 cells. Interestingly, EVs derived from HBV-infected #28.3.25.13 cells included higher level of mitochondrial DNA (mtDNA) than those from HBV-infected #28.3.8 cells. Based on our results, we propose the novel model that EVs mediate the activation of ATM-Chk2 signaling pathway by the intercellular transfer of mtDNA in HBV-infected human hepatocyte.

How to identify indolent thyroid tumors unlikely to recur and cause cancer death immediately after surgery-Risk stratification of papillary thyroid carcinoma in young patients.

Current histopathological diagnosis methods cannot distinguish the two types of thyroid carcinoma: clinically significant carcinomas with a potential risk of recurrence, metastasis, and cancer death, and clinically insignificant carcinomas with a slow growth rate. Both thyroid tumors are diagnosed as "carcinoma" in current pathology practice. The clinician usually recommends surgery to the patient and the patient often accepts it because of cancer terminology. The treatment for these clinically insignificant carcinomas does not benefit the patient and negatively impacts society. The author proposed risk stratification of thyroid tumors using the growth rate (Ki-67 labeling index), which accurately differentiates four prognostically relevant risk groups based on the Ki-67 labeling index, ≥30%, ≥10 and <30%, >5 and <10%, and ≤5%. Indolent thyroid tumors with an excellent prognosis have the following four features: young age, early-stage (T1-2 M0), curatively treated, and low proliferation index (Ki-67 labeling index of ≤5%), and are unlikely to recur, metastasize, or cause cancer death. Accurate identification of these indolent tumors helps clinicians select more conservative treatments to avoid unnecessary aggressive (total thyroidectomy followed by radio-active iodine) treatments. Clinicians can alleviate the fears of patients by confirming these four features, including the low proliferation rate, in a pathology report immediately after surgery when patients are most concerned.

Additional Tissue Sampling Trials Did Not Change Our Thyroid Practice.

This study aimed to determine whether additional tissue sampling of encapsulated thyroid nodules would increase the frequency of follicular thyroid carcinoma (FTC) diagnoses. We examined thyroid tissue specimens from 86 patients suspected of FTC (84.9% female; mean age, 49.0 ± 17.8 years). The number of tissue blocks created for pathological assessments ranged from 3 to 20 (mean, 9.1 ± 4.1); the numbers in the previous method recommended by the Japanese General Rules for the Description of Thyroid Cancer and additional blocks ranged from 1 to 12 (mean, 6.0 ± 2.8) and from 1 to 8 (mean, 3.1 ± 2.0), respectively. The additional blocks were subsequently examined to determine whether any diagnoses changed from those based on the previous method. Five patients were diagnosed with FTC using the previous method; however, additional tissue blocks led to the diagnosis of FTC in 6 patients, as 1 diagnosis was revised from follicular adenoma to FTC. It has been reported that increasing the number of tissue blocks used for pathological assessments can increase the frequency of FTC diagnoses; however, this was not clinically significant in thyroid carcinoma, which requires completion thyroidectomy and radioactive iodine treatment. It resulted in no benefits to the patient because all minimally invasive FTCs, follicular tumors of uncertain malignant potential (FT-UMP), and follicular adenomas are treated with lobectomy alone in Japan. Additional tissue sampling only had a slight impact on our thyroid practice; therefore, we decided to cease it.

Cytologic diagnosis of medullary thyroid carcinoma in the Asia-Pacific region.

BACKGROUND: The accurate preoperative identification of medullary thyroid carcinoma (MTC) is challenging due to the rarity of tumor and variable cytologic appearance. The Asian experience with diagnosing MTC by fine-needle aspiration (FNA) was scarcely reported. METHODS: Cases of MTC with available FNA slides were enrolled from 13 hospitals representing 8 Asia-Pacific countries. Clinicopathological information, including sample preparation technique, staining method, original cytologic diagnosis and review diagnosis were collected. RESULTS: Of a total of 145 MTC cases retrospectively recruited, 99 (68.3%) were initially interpreted as MTC/suspicious for MTC (S-MTC). The distribution of original FNA diagnostic categories was not associated with the staining method or sample preparation technique. The staining methods used were Papanicolaou, hematoxylin-eosin and Romanowsky stains. Liquid-based cytology (LBC) was used only in three countries. After reviewing all cases, the diagnostic rate of MTC/S-MTC increased to 91.7% (133/145). Cases with initially unrecognized MTC had either marked pleomorphism or cytology mimicking papillary carcinoma or follicular neoplasm. Although LBC provided certain benefits, there was no significant difference in diagnostic accuracy between conventional smear and LBC. Immunocytochemistry was available in 38 cases (26.2%), all of which were correctly recognized as MTC. CONCLUSION: Our report summarizes how MTC is handled in contemporary Asian thyroid FNA practice. Although the detection rate of MTC by cytology alone is less satisfactory, integration with ancillary tests could achieve an excellent performance. The recognition of constitutive cytomorphologic features is needed for each cytopreparatory method, which may result in a lower threshold to initiate further workup for MTC.

PRIMARY HYPERPARATHYROIDISM ACCOMPANIED BY RECOVERY OF PARATHYROID BLOOD FLOW THREE MONTHS AFTER SPONTANEOUS PARATHYROID HEMORRHAGE.

OBJECTIVE: The objective of this report was to describe an unusual case of emerging primary hyperparathyroidism (PHPT) accompanied by recovery of parathyroid blood flow 3 months after spontaneous parathyroid hemorrhage. METHODS: Neck images and laboratory tests including serum calcium and parathyroid hormone (PTH) were performed to evaluate parathyroid hemorrhage. Pathologic findings after parathyroidectomy are also presented. RESULTS: A 58-year-old woman developed acute onset of neck pain and swelling with ecchymosis. Computed tomography showed a right paratracheal hematoma-like lesion behind the thyroid. Ultrasound (US) of the neck revealed a round, hypoechoic nodule measuring 27 × 25 × 18 mm in the right lower thyroid pole without vascular flow. Blood tests showed a corrected calcium of 9.3 mg/dL (normal, 8.7 to 10.3 mg/dL), and intact PTH of 68 pg/mL (normal, 10 to 65 pg/mL). Intact PTH measurement in fine-needle aspirate of the lesion was 339 pg/mL, confirming parathyroid origin. Repeat US after 3 months showed a remarkable decrease in lesion size with significant blood flow. Blood biochemistry showed a corrected calcium of 10.9 mg/dL, and an intact PTH of 237 pg/mL. She eventually underwent parathyroidectomy, and pathologic examination revealed parathyroid adenoma with a tiny thrombus. CONCLUSION: Spontaneous remission of PHPT after parathyroid hemorrhage has been known to occur sporadically, a phenomenon referred to as autoparathyroidectomy. Although spontaneous remission with permanent improvement of PHPT may be observed, PHPT can recur in the relative short term after parathyroid hemorrhage, and so follow-up blood biochemistry surveillance is necessary. Also, evaluating parathyroid blood flow using color Doppler US might be useful in verifying the recurrence of PHPT.

Prevalence and diagnostic challenges of thyroid lymphoma: a multi-institutional study in non-Western countries.

Research on the primary thyroid lymphoma (PTL) diagnosis is limited, with only a few large sample size studies, reported from Asian countries. The aim of the present study was to clarify the current prevalence and challenges in PTL diagnosis, and recommended ancillary studies for PTL in non-Western countries. PTL (n = 153) cases were retrieved from 10 institutions in non-Western countries and analyzed. Ultrasound examination (UE) and fine needle aspiration cytology (FNAC) were used as main preoperative diagnostic tools in all participating institutions. Flow cytometry (FCM) was performed in the 5 institutions (50%). Lobectomy was the most common histological procedure to confirm the PTL diagnosis. All institutions routinely performed immuno-histochemical analysis. PTL was 0.54% of malignant thyroid tumor cases, with mucosa-associated lymphoid tissue lymphoma (MALTL) and diffuse large B-cell lymphoma (DLBCL) being 54.9% and 38.6%, respectively. Kuma Hospital, where the frequency of MALTL was highest (83.7%), routinely performed FCM using the materials obtained by FNAC. UE and FNAC sensitivities were 62.5% and 57.8%, respectively. In both UE and FNAC, sensitivity of MALTL was lower than of DLBCL. The study elucidated that the prevalence of PTL in non-Western countries was lower than previously reported. We propose that FCM should be more actively used to improve the preoperative diagnosis of MALTL. Our data predicted that the MALTL proportion will increase with improved diagnostic tools, while observation of PTL-suspected nodules without histological examination remains a viable option.

Study of multiple genetic variations caused by persistent hepatitis C virus replication in long-term cell culture.

The most characteristic feature of the hepatitis C virus (HCV) genome in patients with chronic hepatitis C is its remarkable variability and diversity. To better understand this feature, we performed genetic analysis of HCV replicons recovered from two human hepatoma HuH-7-derived cell lines after 1, 3, 5, 7, and 9 years in culture: The cell lines 50-1 and sO harbored HCV 1B-1 and O strain-derived HCV replicons established in 2002 and 2003, respectively. The results revealed that genetic variations in both replicons accumulated in a time-dependent manner at a constant rate despite the maintenance of moderate diversity (less than 1.8% difference) between the clones and that the mutation rate in the 50-1 and sO replicons was 2.5 and 2.9 × 10-3 base substitutions/site/year, respectively. We found that the genetic distance of both replicons increased from 7.9% to 10.5% after 9 years in culture. In addition, we observed that the guanine + cytosine (GC) content of both replicon RNAs increased in a time-dependent manner, as observed in our previous studies. Finally, we demonstrated that the high sensitivity of both replicons to direct-acting antivirals was maintained even after 9 years in culture. Our results suggest that long-term cultured HCV replicon-harboring cells are a useful model for understanding the variability and diversity of the HCV genome and the drug sensitivity of HCV in patients with chronic hepatitis C.

Recurrence, death, and secondary malignancy after ovarian conservation for young women with early-stage low-grade endometrial cancer.

OBJECTIVE: To examine the association between ovarian conservation and oncologic outcome in surgically-treated young women with early-stage, low-grade endometrial cancer. METHODS: This multicenter retrospective study examined women aged <50 with stage I grade 1-2 endometrioid endometrial cancer who underwent primary surgery with hysterectomy from 2000 to 2014 (US cohort n = 1196, and Japan cohort n = 495). Recurrence patterns, survival, and the presence of a metachronous secondary malignancy were assessed based on ovarian conservation versus oophorectomy. RESULTS: During the study period, the ovarian conservation rate significantly increased in the US cohort from 5.4% to 16.4% (P = 0.020) whereas the rate was unchanged in the Japan cohort (6.3-8.7%, P = 0.787). In the US cohort, ovarian conservation was not associated with disease-free survival (hazard ratio [HR] 0.829, 95% confidence interval [CI] 0.188-3.663, P = 0.805), overall survival (HR not estimated, P = 0.981), or metachronous secondary malignancy (HR 1.787, 95% CI 0.603-5.295, P = 0.295). In the Japan cohort, ovarian conservation was associated with decreased disease-free survival (HR 5.214, 95% CI 1.557-17.464, P = 0.007) and an increased risk of a metachronous secondary malignancy, particularly ovarian cancer (HR 7.119, 95% CI 1.349-37.554, P = 0.021), but was not associated with overall survival (HR not estimated, P = 0.987). Ovarian recurrence or metachronous secondary ovarian cancer occurred after a median time of 5.9 years, and all cases were salvaged. CONCLUSION: Our study suggests that adoption of ovarian conservation in young women with early-stage low-grade endometrial cancer varies by population. Ovarian conservation for young women with early-stage, low-grade endometrial cancer may be potentially associated with increased risks of ovarian recurrence or metachronous secondary ovarian cancer in certain populations; nevertheless, ovarian conservation did not negatively impact overall survival.

Tumor characteristics and outcome of uterine carcinosarcoma in women aged ≥80 years.

OBJECTIVE: To examine clinico-pathological characteristics and outcomes of uterine carcinosarcoma (UCS) in women aged ≥80 years. METHODS: This is a secondary analysis of a previous multicenter retrospective study examining 906 women with stage I-IV UCS who underwent primary hysterectomy. Patient demographics, treatment types, tumor characteristics, and survival were examined across aged ≥80 (n = 82 [9.1%]), aged 60-79, (n = 526 [58.1%]), and aged <60 (n = 298 [32.9%]). RESULTS: Women in the aged ≥80 group were more likely to be Caucasian, undergo simple hysterectomy without lymphadenectomy, and receive no postoperative therapy (all, P < 0.05). Tumors in the aged ≥80 group were more likely to have high-grade carcinoma, heterologous sarcoma, and sarcoma dominance but less likely to have lympho-vascular space invasion (all, P < 0.05). Lymphadenectomy did not improve survival in the aged ≥80 group (P > 0.05), whereas lymphadenectomy was protective for survival in the younger groups (both, P < 0.05). Postoperative chemotherapy was associated with improved progression-free survival (PFS) in the aged ≥80 group (hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.22-0.89, P = 0.021). With chemotherapy treatment, women in the aged ≥80 group had PFS similar to those in the aged 60-79 group (HR 0.97, 95%CI 0.51-1.83, P = 0.92). In contrast, without chemotherapy treatment, women in the aged ≥80 group had significantly decreased PFS compared to the aged 60-79 group (HR 1.62, 95%CI 1.09-2.40, P = 0.016). Similar associations were observed for postoperative radiotherapy. CONCLUSION: Nearly 10% of women with UCS are aged ≥80 that are characterized by aggressive tumor factors. Postoperative therapy but not extensive surgery may improve survival in this age group.

A new hepatoma cell line exhibiting high susceptibility to hepatitis B virus infection.

Hepatitis B virus (HBV) infection, which increases the risk of cirrhosis and hepatocellular carcinoma and requires lifelong treatment, has become a major global health problem. However, host factors essential to the HBV life cycle are still unclear, and the development of new drugs is needed. Cells derived from the human hepatoma cell line HepG2 and engineered to overexpress sodium taurocholate cotransporting polypeptide (NTCP: a receptor for HBV), termed HepG2/NTCP cells, are widely used as the cell-based HBV infection and replication systems for HBV research. We recently found that human hepatoma cell line Li23-derived cells overexpressing NTCP (A8 cells subcloned from Li23 cells), whose gene expression profile was distinct from that of HepG2/NTCP cells, were also sensitive to HBV infection. However, the HBV susceptibility of A8 cells was around 1/100 that of HepG2/NTCP cells. Since we considered that plural cell assay systems will be needed for the objective evaluation of anti-HBV reagents, as we previously demonstrated in hepatitis C virus research, we here attempted to develop a new Li23 cell-derived assay system equivalent to that using HepG2/NTCP cells. By repeated subcloning of A8 cells, we successfully established a new cell line (A8.15.78.10) exhibiting high HBV susceptibility equal to that of HepG2/NTCP cells. Characterization of A8.15.78.10 cells revealed that the increase of HBV susceptibility was correlated with increases in the protein and glycosylation levels of NTCP, and with decreased expression of STING, a factor contributing to innate immunity. Finally, we performed a comparative evaluation of HBV entry inhibitors (cyclosporin A and rosiglitazone) by an HBV/secNL reporter assay using A8.15.78.10 cells or HepG2/NTCP cells. The results confirmed that cyclosporin A exhibited anti-HBV activity in both cell lines, as previously reported. However, we found that rosiglitazone did not show the anti-HBV activity in A8.15.78.10 cells, although it worked in HepG2/NTCP cells as previously reported. This suggested that the difference in anti-HBV activity between cyclosporin A and rosiglitazone was due to the different types of cells used for the assay. In conclusion, plural assay systems using different types of cells are required for the objective and impartial evaluation of anti-HBV reagents.

Ribavirin-induced down-regulation of CCAAT/enhancer-binding protein α leads to suppression of lipogenesis.

Recently, we demonstrated that the anti-viral drug ribavirin (RBV) had the ability to suppress lipogenesis through down-regulation of retinoid X receptor α (RXRα) under the control of the intracellular GTP-level and AMP-activated protein kinase-related kinases, especially microtubule affinity regulating kinase 4 (MARK4). RXRα-overexpression attenuated but did not abolish lipogenesis suppression by RBV, implying that additional factor(s) were involved in this suppressive effect. In the present study, we found that the protein level, but not the mRNA level, of CCAAT/enhancer-binding protein α (C/EBPα) was down-regulated by RBV in hepatic cells. Treatment with proteasome inhibitor attenuated RBV-induced down-regulation of C/EBPα, suggesting that RBV promoted degradation of C/EBPα protein via the ubiquitin-proteasome pathway. Depletion of intracellular GTP through inosine monophosphate dehydrogenase inhibition by RBV led to down-regulation of C/EBPα. In contrast, down-regulation of C/EBPα by RBV was independent of RXRα and MARK4. Knockdown of C/EBPα reduced the intracellular neutral lipid levels and the expression of genes related to the triglyceride (TG) synthesis pathway, especially glycerol-3-phosphate acyltransferase, mitochondrial (GPAM), which encodes the first rate-limiting TG enzyme. Overexpression of C/EBPα yielded the opposite results. We also observed that RBV decreased GPAM expression. Moreover, overexpression of GPAM attenuated RBV-induced reduction in the intracellular neutral lipid levels. These data suggest that down-regulation of C/EBPα by RBV leads to the reduction in GPAM expression, which contributes to the suppression of lipogenesis. Our findings about the mechanism of RBV action in lipogenesis suppression will provide new insights for therapy against the active lipogenesis involved in hepatic steatosis and hepatocellular carcinomas.

High-level expression of STING restricts susceptibility to HBV by mediating type III IFN induction.

Hepatitis B virus (HBV) is a hepatotropic DNA virus causing hepatic diseases such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. To study HBV, human hepatoma HepG2 cells are currently used as an HBV infectious cell culture model worldwide. HepG2 cells exhibit susceptibility to HBV by exogenously expressing sodium taurocholate cotransporting polypeptide (NTCP). We herein demonstrated that human immortalized hepatocyte NKNT-3 cells exhibited susceptibility to HBV by exogenously expressing NTCP (NKNT-3/NTCP cells). By comparing cyclic GMP-AMP synthetase (cGAS)-stimulator of interferon genes (STING) signaling pathway in several NKNT-3/NTCP cell-derived cell clones, we found that STING was highly expressed in cell clones exhibiting resistance but not susceptibility to HBV. High-level expression of STING was implicated in HBV-triggered induction of type III IFN and a pro-inflammatory cytokine, IL-6. In contrast, RNAi-mediated knockdown of STING inhibited type III IFN induction and restored the levels of HBV total transcript in an HBV-infected cell clone exhibiting resistance to HBV. These results suggest that STING regulates susceptibility to HBV by its expression levels. STING may thus be a novel target for anti-HBV strategies.

Characterizing sarcoma dominance pattern in uterine carcinosarcoma: Homologous versus heterologous element.

OBJECTIVE: To examine significance of sarcoma dominance (SD) patterns in uterine carcinosarcoma (UCS). METHODS: This is a secondary analysis of multicenter retrospective study examining women with stages I-IV UCS who underwent primary surgery. SD was defined as >50% of sarcoma component in uterine tumor. SD patterns were grouped as homologous sarcoma without SD (homo/non-dominance, n = 351), heterologous sarcoma without SD (hetero/non-dominance, n = 174), homologous sarcoma with SD (homo/dominance, n = 175), and heterologous sarcoma with SD (hetero/dominance, n = 189), and correlated to tumor characteristics and survival. RESULTS: SD patterns were significantly associated with age, body habitus, carcinoma type, tumor size, depth of myometrial invasion, and nodal metastasis (all, P < 0.05). On univariate analysis, SD was associated with decreased progression-free survival (PFS) and cause-specific survival (CSS) in homologous cases (both, P < 0.05) but not in heterologous cases. On multivariate models, both homologous and heterologous SD patterns remained independent prognostic factors for decreased PFS (adjusted-hazard ratio [HR] ranges: homo/dominance 1.35-1.69, and hetero/dominance 1.47-1.64) and CSS (adjusted-HR ranges: 1.52-1.84 and 1.66-1.81, respectively) compared to homo/non-dominance (all, P < 0.05). Among stage I-III disease, when tumors had SD, adding radiotherapy to chemotherapy was significantly associated with improved PFS (adjusted-HR: homo/dominance 0.49, and hetero/dominance 0.45) and CSS (0.36 and 0.31, respectively) compared to chemotherapy alone (all, P < 0.05); contrary, this association was not observed with absence of SD (all, P > 0.05). CONCLUSION: In UCS, SD impacts survival in homologous but not in heterologous type. Regardless of sarcoma types, SD was associated with decreased survival in UCS; adding radiotherapy to chemotherapy may be an effective postoperative strategy.

Daunorubicin, a topoisomerase II poison, suppresses viral production of hepatitis B virus by inducing cGAS-dependent innate immune response.

Hepatitis B virus (HBV) causes hepatic diseases such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. These diseases are closely associated with persistent HBV infection. To prevent the progression of hepatic diseases, it is thus important to suppress persistent HBV infection. Daunorubicin (DNR), a topoisomerase II (Top II) poison, is a clinically used anticancer agent with a wide spectrum of activity against malignancies. DNR was recently reported to cause DNA damage-dependent interferon (IFN)-ß induction through exogenous cyclic GMP-AMP synthetase (cGAS) and subsequently to suppress Ebola virus replication. In the present study, we demonstrated that DNR caused the inhibition of cell proliferation, but not cell death, through the DNA damage response in immortalized human hepatocyte NKNT-3/NTCP cells. Interestingly, DNR triggered the endogenous cGAS-dependent innate immune response and subsequently suppressed viral production of HBV in NKNT-3/NTCP cells. Top II poisons may be anti-HBV drug candidates.

Proposal for a Risk-Based Categorization of Uterine Carcinosarcoma.

PURPOSE: To propose a categorization model of uterine carcinosarcoma (UCS) based on tumor cell types (carcinoma and sarcoma) and sarcoma dominance. METHODS: This secondary analysis of a prior multicenter retrospective study examined 889 cases of UCS with available histologic evaluation. Based on survival outcome, cases were clustered into three groups: low-grade carcinoma with nondominant homologous sarcoma [type A, n = 96 (10.8%)], (1) low-grade carcinoma with heterologous sarcoma or any sarcoma dominance and (2) high-grade carcinoma with nondominant homologous sarcoma [type B, n = 412 (46.3%)], and high-grade carcinoma with heterologous sarcoma or any sarcoma dominance [type C, n = 381 (42.9%)]. Tumor characteristics and outcome were examined based on the categorization. RESULTS: Women in type C category were more likely to be older, obese, and Caucasian, whereas those in type A category were younger, less obese, Asian, and nulligravid (all P < 0.01). Type C tumors were more likely to have metastatic implants, large tumor size, lymphovascular space invasion with sarcoma cells, and higher lymph node ratio, whereas type A tumors were more likely to be early-stage disease and small (all P < 0.05). On multivariate analysis, tumor categorization was independently associated with progression-free survival (5-year rates: 70.1% for type A, 48.3% for type B, and 35.9% for type C, adjusted P < 0.01) and cause-specific survival (5-year rates: 82.8% for type A, 63.0% for type B, and 47.1% for type C, adjusted P < 0.01). CONCLUSION: Characteristic differences in clinicopathological factors and outcomes in UCS imply that different underlying etiologies and biological behaviors may be present, supporting a new classification system.

Significance of Lymphovascular Space Invasion by the Sarcomatous Component in Uterine Carcinosarcoma.

OBJECTIVE: The aim of this study was to examine the significance of lymphovascular space invasion (LVSI) with a sarcomatous component on the tumor characteristics and clinical outcomes of women with uterine carcinosarcoma (UCS). METHODS: This was a secondary analysis of a prior multicenter retrospective study that examined women with stage I-IV UCS who underwent primary hysterectomy. Archived histopathology slides were reviewed and LVSI was scored as follows: LVSI with a carcinomatous component alone (LVSI-carcinoma; n = 375, 76.8%) or LVSI containing a sarcomatous component with or without a carcinomatous component (LVSI-sarcoma; n = 113, 23.2%). Qualitative metrics of LVSI were correlated to clinicopathological factors and survival outcome. RESULTS: Tumors in the LVSI-sarcoma group were more likely to have sarcoma dominance (82.1 vs. 26.4%) heterologous sarcomatous component (51.3 vs. 37.9%), low-grade carcinoma (42.5 vs. 22.4%), and large tumor size (81.0 vs. 70.2%) in the primary tumor site compared with tumors in the LVSI-carcinoma group (all p < 0.05). On multivariate analysis, LVSI-sarcoma was independently associated with decreased progression-free survival (5-year rates: 34.9 vs. 40.8%, adjusted hazard ratio [HR] 1.84, 95% confidence interval [CI] 1.36-2.50, p < 0.001), and cause-specific survival (5-year rates: 41.8 vs. 55.9%, adjusted HR 1.95, 95% CI 1.39-2.75, p < 0.001) compared with LVSI-carcinoma. Postoperative radiotherapy for women with LVSI-sarcoma had a higher reduction rate of recurrence/progression of disease (54% reduction, p = 0.04) compared with postoperative radiotherapy for women with LVSI-carcinoma (26% reduction, p = 0.08). CONCLUSION: In UCS, the presence of a sarcomatous component in LVSI is particularly prevalent when a tumor has sarcoma dominance. Our study suggests that LVSI containing a sarcomatous component may be a predictor of decreased survival for women with UCS.

Impact of non-invasive follicular thyroid neoplasm with papillary-like nuclear features on the Bethesda system for reporting thyroid cytopathology: a multi-institutional study in five Asian countries.

Several Western studies showed that the recent introduction of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) significantly decreased risk of malignancy for cytological diagnostic categories. We aimed to determine the impact of NIFTP on risk of malignancy within a cohort of thyroid nodules from Asian countries, and to compare distribution of diagnostic categories between NIFTP and invasive encapsulated follicular variant of papillary thyroid carcinoma (eFV-PTC). Consecutive thyroid fine-needle aspirates from six institutions were retrospectively analysed. Histopathology slides with a diagnosis of eFV-PTC were reviewed and reclassified into invasive eFV-PTC and NIFTP. The risk of malignancy was calculated with and without NIFTP. Of 11,372 thyroid nodules, 2044 had available surgical follow-up. NIFTP was diagnosed in 59 cases, which constituted 2.9% of all excised nodules, and 5.3% of malignant nodules. Preoperative cytological diagnoses for NIFTP were non-diagnostic (10.2%), benign (18.6%), atypia of undetermined significance/follicular lesion of undetermined significance (22.0%), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN) (32.2%), suspicious for malignancy (SM) (11.9%), and malignant (5.1%). The only category which showed a relative reduction in risk of malignancy after reclassification of more than 20%, was FN/SFN (24.4%). There was a significantly higher prevalence of benign cytology in NIFTP (p = 0.04) and SM/malignant in invasive eFV-PTC (p = 0.05). A majority of NIFTP cases were classified in indeterminate categories, which decreased the corresponding risk of malignancy. However, the magnitude of NIFTP impact was much lower than in the Western reports. Asian countries may not experience significant effects of NIFTP reclassification on the practice of thyroid cytopathology.

ULBP1 is induced by hepatitis C virus infection and is the target of the NK cell-mediated innate immune response in human hepatocytes.

Natural killer (NK) cells through their NK group 2 member D (NKG2D) receptors recognize NKG2D ligands such as UL16-binding proteins (ULBPs) on virus-infected cells and subsequently trigger the host innate immune response. In the present study, we demonstrated that hepatitis C virus (HCV) induced the cell surface expression of ULBP1 in human immortalized hepatocyte PH5CH8 cells and human hepatoma HuH-7 cell-derived RSc cells. Interestingly, NK cell line NK-92 induced cytotoxicity and interferon-γ mRNA expression and subsequently reduced the levels of HCV RNA replication during co-culture with HCV-infected RSc cells. From these results, we conclude that ULBP1 is a target of the NK cell-mediated innate immune response in HCV-infected human hepatocytes.