Genetic analysis of low-grade adenosquamous carcinoma of the breast progressing to high-grade metaplastic carcinoma.

PURPOSE: Low-grade adenosquamous carcinoma (LGASC) is a rare type of metaplastic carcinoma of the breast (MBC) with an indolent clinical course. A few LGASC cases with high-grade transformation have been reported; however, the genetics underlying malignant progression of LGASC remain unclear. METHODS: We performed whole-genome sequencing analysis on five MBCs from four patients, including one case with matching primary LGASC and a lymph node metastatic tumor consisting of high-grade MBC with a predominant metaplastic squamous cell carcinoma component (MSC) that progressed from LGASC and three cases of independent de novo MSC. RESULTS: Unlike de novo MSC, LGASC and its associated MSC showed no TP53 mutation and tended to contain fewer structural variants than de novo MSC. Both LGASC and its associated MSC harbored the common GNAS c.C2530T:p.Arg844Cys mutation, which was more frequently detected in the cancer cell fraction of MSC. MSC associated with LGASC showed additional pathogenic deletions of multiple tumor-suppressor genes, such as KMT2D and BTG1. Copy number analysis revealed potential 18q loss of heterozygosity in both LGASC and associated MSC. The frequency of SMAD4::DCC fusion due to deletions increased with progression to MSC; however, chimeric proteins were not detected. SMAD4 protein expression was already decreased at the LGASC stage due to unknown mechanisms. CONCLUSION: Not only LGASC but also its associated high-grade MBC may be genetically different from de novo high-grade MBC. Progression from LGASC to high-grade MBC may involve the concentration of driver mutations caused by clonal selection and inactivation of tumor-suppressor genes.

Machine learning-based image analysis for accelerating the diagnosis of complicated preneoplastic and neoplastic ductal lesions in breast biopsy tissues.

PURPOSE: Diagnosis of breast preneoplastic and neoplastic lesions is difficult due to their similar morphology in breast biopsy specimens. To diagnose these lesions, pathologists perform immunohistochemical analysis and consult with expert breast pathologists. These additional examinations are time-consuming and expensive. Artificial intelligence (AI)-based image analysis has recently improved, and may help in ordinal pathological diagnosis. Here, we showed the significance of machine learning-based image analysis of breast preneoplastic and neoplastic lesions for facilitating high-throughput diagnosis. METHODS: Images were obtained from normal mammary glands, hyperplastic lesions, preneoplastic lesions and neoplastic lesions, such as usual ductal hyperplasia (UDH), columnar cell lesion (CCL), ductal carcinoma in situ (DCIS), and DCIS with comedo necrosis (comedo DCIS) in breast biopsy specimens. The original enhanced convoluted neural network (CNN) system was used for analyzing the pathological images. RESULTS: The AI-based image analysis provided the following area under the curve values (AUC): normal lesion versus DCIS, 0.9902; DCIS versus comedo DCIS, 0.9942; normal lesion versus CCL, 0.9786; and UDH versus DCIS, 1.000. Multiple comparison analysis showed precision and recall scores similar to those of single comparison analysis. Based on the gradient-weighted class activation mapping (Grad-CAM) used to visualize the important regions reflecting the result of CNN analysis, the ratio of stromal tissue in the whole weighted area was significantly higher in UDH and CCL than that in DCIS. CONCLUSIONS: These analyses may provide a more accurate and rapid pathological diagnosis of patients. Moreover, Grad-CAM identifies uncharted important histological characteristics for newer pathological findings and targets of research for understanding diseases.

Pulmonary adenocarcinoma with high-grade fetal adenocarcinoma component has a poor prognosis, comparable to that of micropapillary adenocarcinoma.

Fetal adenocarcinoma is a rare variant of lung adenocarcinoma, which is subcategorized into low-grade and high-grade forms. High-grade fetal adenocarcinoma confers worse prognosis than low-grade fetal adenocarcinoma, but the prognostic differences between high-grade fetal adenocarcinoma and conventional lung adenocarcinoma are unknown. We reviewed tissue sections of 3719 cases of surgically resected primary lung cancers and found 53 lung cancers with a high-grade fetal adenocarcinoma component. We analyzed their clinicopathological and immunohistochemical features, and performed a prognostic analysis of adenocarcinomas with the fetal-type component. We further analyzed the prognostic differences between adenocarcinomas with the fetal-type component and conventional adenocarcinomas without the fetal-type component. Lung cancers with the fetal-type component predominantly occurred in elderly men with a smoking history. Twenty-nine patients had stage I disease, 13 patients had stage II, and 11 patients had stage III. The fetal-type histology was combined with conventional-type adenocarcinoma (41 cases), squamous cell carcinoma (5 cases), large cell neuroendocrine carcinoma (5 cases), enteric adenocarcinoma (2 cases), and small cell carcinoma (1 case). The fetal-type component showed immunopositivity for α-fetoprotein (39%), glypican-3 (37%), and SALL4 (17%). The 5-year overall survivals of fetal-type-predominant and fetal-type-nonpredominant patients were 44 and 56%, respectively (P = 0.962). The 5-year overall survivals of lepidic-, acinar-, papillary-, solid-, and micropapillary-predominant adenocarcinomas, invasive mucinous adenocarcinomas, and adenocarcinomas with the fetal-type component were 94, 82, 77, 69, 57, 83, and 41%, respectively (P < 0.001). Univariate and multivariate analyses showed that adenocarcinomas with the fetal-type component had a significantly lower overall survival rate than the other histological subtypes, except for the micropapillary-predominant subtype. Our study demonstrated that adenocarcinomas with the fetal-type component had a poor prognosis that was comparable to that of micropapillary adenocarcinoma. The presence of the high-grade fetal adenocarcinoma component in lung adenocarcinomas is an important prognostic marker.

Risk factors associated with the progression and metastases of hindgut neuroendocrine tumors: a retrospective study.

BACKGROUND: The worldwide incidence of neuroendocrine tumors (NETs) has increased remarkably, with the hindgut being the second most common site for such tumors. However, the mechanisms underlying progression and metastasis of hindgut NETs are unclear. A retrospective study was conducted to elucidate these mechanisms. METHODS: Clinicopathological data of cases of hindgut NET between April 1996 and September 2015 were analyzed, retrospectively. Patients with neuroendocrine carcinoma were excluded. Formalin-fixed paraffin-embedded tissues of hindgut NET cases were subjected to detailed morphometric and immunohistochemical analyses. Statistical analyses were performed using the non-parametric Mann-Whitney U test, Spearman's correlation coefficient, and chi-squared test. Multivariate logistic regression analysis was conducted as appropriate for the data set. RESULTS: Fifty-six hindgut NET cases were considered. Microvessel density and lymphatic microvessel density were identified as significant risk factors for venous and lymphatic invasion. There was a positive correlation between microvessel density and the maximum tumor diameter. Multivariate logistic regression analysis revealed that the maximum tumor diameter alone was an independent predictor of lymph node metastasis, whereas lymphovascular invasion and MVD was not the predictor of lymph node metastasis. There were no significant correlations between the Ki-67 labeling index and any of the parameters evaluated including age, sex, the maximum tumor diameter, venous invasion, lymphatic invasion, microvessel density, lymphatic microvessel density, and lymph node metastasis. CONCLUSIONS: Angiogenic mechanisms may play important roles in the progression of hindgut NET. Otherwise, the maximum tumor diameter alone was an independent predictor of lymph node metastasis in hindgut NETs. Moreover, our study raises the question of whether the presence of lymphovascular invasion, in endoscopically obtained hindgut NET tissues, is an absolute indication for additional surgery or not.

Expression of enhancer of zeste homolog 2 correlates with survival outcome in patients with metastatic breast cancer: exploratory study using primary and paired metastatic lesions.

BACKGROUND: In metastatic breast cancer, the status of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), as well as the Ki-67 index sometimes change between primary and metastatic lesions. However, the change in expression levels of enhancer of zeste homolog 2 (EZH2) between primary and metastatic lesions has not been determined in metastatic breast cancer. METHODS: Ninety-six metastatic breast cancer patients had biopsies or resections of metastatic lesions between September 1990 and February 2014 at the Kanagawa Cancer Center. We evaluated ER, PR, HER2, Ki-67, and EZH2 in primary lesions and their corresponding metastatic lesions using immunohistochemistry. We examined the change in expression of EZH2 between primary and metastatic lesions, the correlation between the expression of EZH2 and the expression of other biomarkers, and the relationship between EZH2 expression and patient outcome in metastatic breast cancer. RESULTS: EZH2 expression was significantly higher in metastatic lesions compared with primary lesions. EZH2 expression was highly correlated with Ki-67 expression in primary and metastatic lesions. High-level expression of EZH2 was associated with poorer disease-free survival (DFS) outcomes in patients with primary lesions (P < 0.001); however, high-level expression of EZH2 was not associated with poorer DFS outcomes in patients with metastatic lesions (P = 0.063). High-level expression of EZH2 was associated with poorer overall survival (OS) postoperatively in patients with primary (P = 0.001) or metastatic lesions (P = 0.005). High-level expression of EZH2 was associated with poorer OS outcomes after recurrence in patients with metastatic lesions (P = 0.014); however, high-level expression of EZH2 was not associated with poorer OS outcomes after recurrence in patients with primary lesions (P = 0.096). High-level expression of EZH2 in metastatic lesions was independently associated with poorer OS outcomes after recurrence. CONCLUSIONS: EZH2 expression was significantly increased in metastatic lesions compared with primary lesions. High-level expression of EZH2 in metastatic lesions was associated with poorer OS outcomes after primary surgery and recurrence.

Chronic lymphocytic leukemia/small lymphocytic lymphoma with t (2;18) (p12;q21) accompanied by a cutaneous nodule with histological features of diffuse large B-cell lymphoma.

A 73-year-old woman presented a 3-year history of indolent enlargement of cutaneous tumor nodules. Peripheral blood flow cytometry revealed thrombocytopenia (platelets; 85,000/µl) and the presence of an abnormal, small B lymphocyte population (CD5+, CD10-, CD20+, CD22+, CD23dim, FMC7+, SmIgλ+, and SmIgκ-; 4,000/µl). Skin biopsy indicated infiltration of CD5+, CD10-, CD20+, BCL2+, BCL6+, and cyclin D1- atypical large B-cells, suggesting diffuse large B-cell lymphoma. Cytogenetic analysis of the peripheral blood revealed a complex karyotype [t (2;18) (p12;q21) and +12]. Fluorescence in situ hybridization detected the presence of BCL2 split signal and the absence of IGH/CCND1 fusion signal. Cervical lymph node biopsy indicated a pseudofollicular pattern. The sequence of immunoglobulin heavy chain variable region from the peripheral blood and the skin tumor contained the same mutated pattern, and therefore, confirmed clonality. Because the patient's clinical course and skin tumor were indolent, the possibility of Richter syndrome was discarded, and the final diagnosis was chronic lymphocytic leukemia/small lymphocytic lymphoma, Rai stage IV and Binet stage C. The patient achieved complete remission after 4 cycles of a fludarabine plus rituximab regimen, without disease progression since >1 year of treatment.

[A Case of Undifferentiated Carcinoma of the Gallbladder].

In this paper, we present a case of undifferentiated carcinoma of the gallbladder, which is a rare disease with poor prognosis. A 77-year-old woman presented with right hypochondralgia. An abdominal CT scan showed a tumor more than 80 mm in diameter invading the liver parenchyma and transverse colon, and showed liver and lymph node metastases. We diagnosed the patient with stage Ⅳ carcinoma of the gallbladder. We resected the gallbladder, S4a plus S5 of the liver, part of the transverse colon, the lymph nodes, the greater omentum, and the extra hepatic bile duct; biliary reconstruction was then performed. Histological examination showed that most areas consisted of undifferentiated cells. The diagnosis of undifferentiated carcinoma was made according to the WHO classification of tumors of the digestive system. No recurrence has been detected for 1 year.

Expression of organic anion-transporting polypeptide 1A2 and organic cation transporter 6 as a predictor of pathologic response to neoadjuvant chemotherapy in triple negative breast cancer.

Organic anion-transporting polypeptide 1A2 (OATP1A2) and organic cation transporter 6 (OCT6) are involved in the uptake of taxanes and anthracyclines, respectively. The aim of this study was to evaluate expression levels of OATP1A2 and OCT6 as a predictor of response to neoadjuvant chemotherapy (NAC) in breast cancer. A total of 124 patients who received anthracycline/taxane-based NAC were included. Expression levels of OATP1A2 and OCT6 were immunohistochemically assessed in core needle biopsies obtained prior to NAC. A pathologic good response (pGR) and a pathologic complete response (pCR) were achieved in 24 and 10 % of patients, respectively. In univariate analysis of the entire cohort, negative hormone receptor (HR) status (pGR and pCR, P < 0.001), high Ki-67 level (pGR, P = 0.03; pCR, P = 0.02), triple negative (TN) subtype (pGR, P = 0.001; pCR, P < 0.001), and high OCT6 (pGR, P = 0.003) were associated with the response. In combined analysis, high OATP1A2/high OCT6 level was also a significant factor for pGR (P = 0.001) and pCR (P = 0.001). Two separate multivariate analyses showed that HR status, TN subtype and combined high OATP1A2/high OCT6 level were significant independent predictors. When TN and non-TN tumors were assessed separately in univariate analysis, high Ki-67 level (P = 0.04) were associated with pGR and combined high OATP1A2/high OCT6 level was associated with both pGR (P = 0.005) and pCR (P = 0.03) in the TN group. Multivariate analysis identified the combined high OATP1A2/high OCT6 level as the sole independent predictor of pGR. In the non-TN group, negative HR status (P = 0.03) and positive HER2 status (P = 0.005) were associated with pGR, but HER2 status was the sole independent predictor of pGR. These results suggest that response-associated predictors may differ between the TN and non-TN tumors. Combined high OATP1A2/high OCT6 may be a potential predictor of response to anthracycline/taxane-based chemotherapy in breast cancer, especially in TN tumors.

Well-differentiated papillary mesothelioma, possibly giving rise to diffuse malignant mesothelioma: a case report.

Well-differentiated papillary mesothelioma (WDPM) is a distinct subtype of mesothelial tumor from diffuse malignant mesothelioma (DMM), with an uncertain malignant potential. The relationship between WDPM and DMM, with regard to the ability of the former to develop into the latter, is also unknown. A 58-year-old woman, diagnosed with a rectal carcinoid tumor, underwent removal of the lymph nodes via the abdomen in 2004. A large number of white miliary nodules were identified on the mesentery and peritoneum, which were histologically diagnosed as WDPM. No further therapy was administered, but the patient was followed-up using imaging methods. Seven years later, an abdominal wall mass was discovered using positron emission tomography-computed tomography, and a laparotomy biopsy was performed. DMM was diagnosed, because mesothelioma with extended invasion had been histologically identified. Mesothelioma similar to papillary proliferation was present on the outer layer of the peritoneum, and an infiltrating lesion with continuous restiform or solid-like structures was noted. WDPM was believed to have undergone malignant transformation. Compared to DMM, WDPM has a good prognosis and is considered a benign or borderline neoplasm. Our findings suggest that WDPM does have malignant potential, however, because histological findings indicated a malignant transformation of WDPM to DMM.

Impacts and predictors of cytotoxic anticancer agents in different breast cancer subtypes.

Breast cancer is not a single entity. This study therefore aimed to identify differences in the impacts of anticancer agents and predictive factors between different breast cancer subtypes. A total of 234 patients with luminal (n = 109), luminal-HER2 (L-H, n = 29), HER-2 (n = 35), or triple negative (TN, n = 61) breast cancer subtypes were treated with standard neoadjuvant chemotherapy consisting of an anthracycline and/or taxane. Pathological response and prognosis were examined in each subtype. Expression levels of estrogen and progesterone receptors, HER-2, nuclear grade, MIB-1, p53, topoisomerase IIalpha (topoIIalpha), cytokeratin (CK) 5/6, and epidermal growth factor receptor (EGFR) were examined in association with quasipathological complete response (QpCR). QpCR rates were 9.1% (10/109) in luminal, 45% (13/29) in L-H, 37% (13/35) in HER2, and 54.1% (33/61) in TN. Non-QpCR patients showed significantly poorer 3-year disease-free survival than QpCR patients in TN, but not in patients with other subtypes. No factors were associated with QpCR in luminal patients. Patients with higher nuclear grade were more likely to achieve QpCR in L-H. The proliferative markers MIB-1 and topoIlalpha had opposite impacts on pathological response in HER-2 and TN. The QpCR rate was significantly higher in TN lacking CK5/6 and/or EGFR expression, defined as nonbasal subtype, compared with basal subtype (p = 0.049). Cytotoxic anticancer agents were associated with different responses in different breast cancer subtypes. Identifying basal-type cancer and further subdivision of nonbasal types is important for treating TN patients.

Signet-ring Cell Carcinoma Component as an Indicator of Anaplastic Lymphoma Kinase Mutations in Colorectal Cancer.

OBJECTIVES: Molecular profiling of marker mutations has become an essential aspect in the treatment planning for colorectal cancer (CRC). Anaplastic lymphoma kinase (ALK) mutations could be used as markers in CRC molecular profiling. However, the extremely low frequency of these mutations makes their confirmation in all patients inefficient. Thus, to determine whether ALK positivity could be indicated by morphological features, we have analyzed ALK positivity in CRC tissues with a signet-ring cell carcinoma (SRCC) component. METHODS: We screened cases of patients who underwent CRC surgical resection at the Department of Gastrointestinal Surgery of the Kanagawa Cancer Center between January 2015 and December 2019. The selected samples were then assessed immunohistochemically using an antibody against p80 ALK. RESULTS: In total, we were able to retrieve 29 cases of CRC with the SRCC component from the database; however, 5 cases were excluded owing to the absence of formalin-fixed paraffin-embedded tissue sections or the absence of the SRCC component when the tissues were observed. In the immunohistochemical analysis, two cases showed diffused positive immunoreactivity for ALK and were defined as ALK-positive CRC. Thus, the ALK positivity rate in CRC with SRCC was determined to be 8.3%. CONCLUSIONS: This present study sheds light on the morphological features of ALK-positive CRC. Our findings could contribute to the effective screening and improvement of front-line therapy for CRC.

Comprehensive molecular analysis of genomic profiles and PD-L1 expression in lung adenocarcinoma with a high-grade fetal adenocarcinoma component.

BACKGROUND: Fetal adenocarcinoma of the lung is a rare variant of lung adenocarcinoma and is subcategorized into low-grade and high-grade (H-FLAC) fetal adenocarcinoma. We previously reported poor prognosis in pulmonary adenocarcinomas with an H-FLAC component; however, the genetic abnormalities involved in H-FLAC remain unclear. Therefore, this study aimed to elucidate molecular abnormalities as potential therapeutic targets for H-FLACs. METHODS: We performed immunohistochemical analysis and comprehensive genetic analyses using whole-exome sequencing in 16 lung cancer samples with an H-FLAC component. DNA was extracted from formalin-fixed paraffin-embedded tissues after macrodissection of the H-FLAC component. RESULTS: Cancer-related mutations were identified in TP53 (7/16 cases), KMT2C (6/16 cases), KRAS (4/16 cases), NF1 (3/16 cases), STK11 (3/16 cases), CTNNB1 (2/16 cases), and EGFR (1/16 cases). A high tumor mutation burden of ≥10 mutations per megabase was observed in 3/16 cases. A high microsatellite instability was not detected in any case. Based on the cosine similarity with the Catalogue of Somatic Mutations in Cancer mutational signatures, H-FLACs were hierarchically clustered into three types: common adenocarcinoma-like (five cases), surfactant-deficient (ten cases), and signatures 2 and 13-related (one case). All common adenocarcinoma-like cases presented thyroid transcription factor-1 (TTF-1) expression, whereas surfactant-deficient cases often presented loss of TTF-1 and surfactant protein expression and included cases with mutations in the surfactant system genes NKX2-1 and SFTPC. H-FLACs displayed low programmed death ligand-1 (PD-L1) expression (1-49% of tumor cells) in 5/16 cases, and no case displayed high PD-L1 expression (≥50% of tumor cells). CONCLUSIONS: This study indicates that lung cancers with an H-FLAC component rarely harbor currently targetable driver gene mutations for lung cancer but display a high frequency of KMT2C mutations. The microsatellite instability, tumor mutation burden, and PD-L1 expression status suggest a poor response to immune checkpoint therapy.

Quality Control of Breast Cancer Surgery Samples: Introducing Time Stamp Checking.

Background: Analytical information obtained from clinical tissue samples has recently become more important due to recent advancements in the clinical practice of medicine, for example, gene panel testing. However, acquiring and managing the sample quality, which greatly influences the analyses, are not sufficient and hence requires immediate attention. We introduced time stamp (TS) recording and documentation using the Standard PREanalytical Code (SPREC) for breast cancer surgery samples to monitor and control their quality. Materials and Methods: The TS recording used SPREC for quality control of each sample by recording seven factors: type of sample, type of collection, warm ischemia time (WIT), cold ischemia time (CIT), fixation type, fixation time (FT), and long-term storage. The responsibilities to record each factor were assigned among group members (breast surgeons, anesthesiologists, pathologists, operating room nurses, and medical technologists in pathology). Results: Records based on SPREC were recorded for 393 surgical cases of first-time breast cancer patients performed at the Kanagawa Cancer Center from May 2018 to April 2019. The vascular clamp time was defined as when skin flap formation was completed, regardless of the surgical procedure. An anesthesiologist recorded the vascular clamp time and sample collection time, and the pathologist recorded the fixation start time and fixation end time. WIT was 23 (3-116) minutes (breast-conserving surgery, 11 [3-38] minutes; mastectomy, 26 [5-116] minutes; and nipple-sparing mastectomy, 39 [31-43] minutes), CIT was 37 (3-1052) minutes, and FT was 43 (17-115) hours. The median CIT and FT were significantly shortened after introducing the TS system, and the variabilities were reduced. Conclusion: A TS system for quality control of breast cancer surgical sample functions well due to the establishment of highly versatile WIT and a working group consisting of multiple members of different occupations who shared roles.

A human epidermal growth factor receptor 2 expression-based approach to neoadjuvant chemotherapy for operable breast cancer.

OBJECTIVE: We investigated the pathological effects of neoadjuvant chemotherapy based on the human epidermal growth factor receptor 2 in operable breast cancer. METHODS: This prospective clinical study was a pilot involving 63 female patients. Before surgery, patients with tumors overexpressing human epidermal growth factor receptor 2 received four cycles of 60 mg/m(2) anthracycline and 600 mg/m(2) cyclophosphamide every 3 weeks, whereas those whose tumors did not overexpress human epidermal growth factor receptor 2 received four cycles of 75 mg/m(2) docetaxel and 600 mg/m(2) cyclophosphamide every 3 weeks. A quasi-pathological complete response (i.e. absence of invasive tumor or only focal residual tumor cells) was the primary endpoint, with compliance and predictors for each regimen as secondary endpoints. If a quasi-pathological complete response was not achieved, then crossover to the alternative treatment was recommended. RESULTS: The quasi-pathological complete response rate was 36.5% (23 of 63) overall, 27.8% (5 of 18) for the anthracycline and cyclophosphamide regimen and 40.0% (18 of 45) for the docetaxel and cyclophosphamide regimen. Docetaxel and cyclophosphamide treatment induced a quasi-pathological complete response in most patients with triple-negative tumors (15 of 19). The relative dose intensity was 97.3% for the anthracycline and cyclophosphamide regimen and 96.6% for the docetaxel and cyclophosphamide regimen. Quasi-pathological complete response to the docetaxel and cyclophosphamide regimen was associated with low estrogen receptor and progesterone receptor expression and high MIB-1 and topoisomerase IIalpha expression, in univariate analyses, but only with low estrogen receptor expression in multivariate analysis. CONCLUSIONS: Selecting neoadjuvant chemotherapy regimens on the basis of individual human epidermal growth factor receptor 2 status improved efficacy, with docetaxel and cyclophosphamide treatment showing particular promise in tumors with the potential to be highly malignant.

Lymphohistiocytoid mesothelioma of the pleura.

Lymphohistiocytoid mesothelioma (LHM), reported to be a rare variant of sarcomatoid mesothelioma, is challenging to differentiate from non-Hodgkin's lymphoma due to marked lymphocytic infiltration. To aid accurate recognition of LHM, we examined immunohistochemical, in situ hybridization (ISH) of Epstein-Barr virus RNA (EBER-1) mRNA, fluorescence ISH (FISH) for homozygous deletion of 9p21, and asbestos analysis in four cases (three men and 1 woman). Three patients died, while Case 4 was still alive 19 months after extrapleural pneumonectomy. Histologically, these cases were characterized by heavy lymphocytic infiltration. All neoplastic cells were positive for calretinin, AE1/AE3, and epithelial membrane antigen, but negative for CEA. EBER1 factor was negative. FISH analysis demonstrated homozygous deletion of the 9p21 locus in three of the four cases. In Case 1: (i) autopsy findings showed mesothelioma primarily located in the right parietal pleura, but metastasized into the left lung and abdominal organs; (ii) the histological findings at autopsy indicated sarcomatoid mesothelioma; and (iii) we found asbestos bodies and fibers in extracts from lung tissue (Cases 1 & 4) using digestion with bleaching fluid. LHM, an infrequent variant of sarcomatoid mesothelioma, displayed homozygous deletion of the 9p21 locus (three of four cases), and has a relatively favorable prognosis for the sarcomatoid type.

Rapidly progressed neuroendocrine carcinoma in the extrahepatic bile duct: a case report and review of the literature.

BACKGROUND: Neuroendocrine carcinoma (NEC) originating from the extrahepatic bile duct (EHBD) is very rare but is known for its aggressiveness and poor prognosis. We herein report a case of rapidly progressed NEC in the extrahepatic bile duct. CASE PRESENTATION: An 84-year-old man was referred to our facility with obstructive jaundice and abdominal pain. Imaging studies revealed an irregular filling defect in the middle bile duct by endoscopic retrograde cholangiopancreatography and an enhanced wall thickening from the middle to distal portion by enhanced computed tomography. The patient was initially diagnosed with extrahepatic cholangiocarcinoma by a bile duct biopsy and underwent pancreatoduodenectomy with lymph node dissection. The pathological findings showed an NEC with an adenosquamous carcinoma component in the extrahepatic bile duct with lymph node metastases. The patient experienced multiple liver metastases 1 month after surgery and died 3 months after surgery. Due to the rapid progression of his disease, his general condition deteriorated, and he was unable to receive any additional treatments, such as chemotherapy. CONCLUSION: As shown in our case, NEC of the EHBD has an extremely poor prognosis and can sometimes progress rapidly. Multimodality treatment should be considered, even in cases of locoregional disease.

EZH2 and MMSET Were Identified as Potentially Useful Therapeutic Targets in Metaplastic Breast Carcinoma.

BACKGROUND/AIM: Metaplastic breast carcinoma (MBC) is a rare malignancy, which is often triple-negative for the hormone receptors and human epidermal growth factor receptor 2, and thus, does not benefit from targeted therapy. In this study, we examined the expression of methylation and demethylation enzymes by immunostaining MBC and the adjacent normal tissues or triple-negative ductal carcinoma (TNDC), and identified alterations that may be used as therapeutic targets. MATERIALS AND METHODS: We retrospectively studied surgical specimens from 15 patients who underwent surgery for MBC at Kanagawa Cancer Center between 2005 and 2016, and similarly from 14 patients with TNDC. The frequencies of high methylation/demethylation enzyme expression were compared among them. RESULTS: The frequencies of high enhancer of zeste homolog 2 (EZH2) and multiple myeloma SET domain (MMSET) expression were significantly higher in both MBC and TNDC than in normal tissue. CONCLUSION: EZH2 and MMSET may be useful therapeutic targets in MBC.

Sebaceous carcinoma of the breast.

Sebaceous carcinoma (SC) of the breast is a rare malignant tumor and only nine cases, including the present one, have been reported in the English-language literature. The present report describes a case of mammary SC in a 50-year-old Japanese woman. The tumor was gray-white on cut surface and separate from the skin and the nipple. Microscopically, lobules encircled by a fibrous envelope and cords or small cell nests in the stroma were noted. These two types of structures were composed of dark cells and clear foamy cells. The dark cells had large nuclei and amphophilic cytoplasm. The clear foamy cells had numerous lipid vacuoles, confirmed on immunostaining with anti-adipophilin antibody and electron microscopy. In the lobules the gradual transitions from basal dark cells to central clear foamy cells and comedo-like necrosis were observed. The tumor cells were positive on immunohistochemistry for cytokeratins (CAM5.2, AE1/AE3), Her2/neu and androgen receptor but negative for estrogen and progesterone receptors. This is the first case of an androgen receptor-positive mammary SC to be reported, and therefore contributes to the understanding of the clinicopathological features of SC of the breast.