PAX2 and PAX8: useful markers for metastatic effusions

Immunochemistry in the work-up of mesothelioma and its differential diagnosis and mimickers

The differential diagnosis in cellular effusions with cytological atypia often includes malignant mesothelioma (MM), reactive mesothelial proliferation, and malignancies of metastatic origin, particularly carcinomas. The International Reporting System for Serous Fluid recently established guidelines for reporting MM. In conjunction with the cytomorphologic evaluation, the role of immunochemistry (IC) was emphasized as a very useful tool in the workup of serous fluids, especially with the availability of novel markers. Utilizing a panel of markers, IC allows the characterization of the cells, whether mesothelial or not, and when mesothelial origin is established, IC can frequently assist in delineating its benign or malignant nature. IC can also confirm metastatic disease, allowing the identification of the primary origin in most cases. This review summarizes the current status of IC and its role in the diagnosis of MM and its differential diagnosis in serous fluids.

An Algorithmic Immunohistochemical Approach to Define Tumor Type and Assign Site of Origin

Immunohistochemistry represents an indispensable complement to an epidemiology and morphology-driven approach to tumor diagnosis and site of origin assignment. This review reflects the state of my current practice, based on 15-years' experience in Pathology and a deep-dive into the literature, always striving to be better equipped to answer the age old questions, "What is it, and where is it from?" The tables and figures in this manuscript are the ones I "pull up on the computer" when I am teaching at the microscope and turn to myself when I am (frequently) stuck. This field is so exciting because I firmly believe that, through the application of next-generation immunohistochemistry, we can provide better answers than ever before. Specific topics covered in this review include (1) broad tumor classification and associated screening markers; (2) the role of cancer epidemiology in determining pretest probability; (3) broad-spectrum epithelial markers; (4) noncanonical expression of broad tumor class screening markers; (5) a morphologic pattern-based approach to poorly to undifferentiated malignant neoplasms; (6) a morphologic and immunohistochemical approach to define 4 main carcinoma types; (7) CK7/CK20 coordinate expression; (8) added value of semiquantitative immunohistochemical stain assessment; algorithmic immunohistochemical approaches to (9) "garden variety" adenocarcinomas presenting in the liver, (10) large polygonal cell adenocarcinomas, (11) the distinction of primary surface ovarian epithelial tumors with mucinous features from metastasis, (12) tumors presenting at alternative anatomic sites, (13) squamous cell carcinoma versus urothelial carcinoma, and neuroendocrine neoplasms, including (14) the distinction of pheochromocytoma/paraganglioma from well-differentiated neuroendocrine tumor, site of origin assignment in (15) well-differentiated neuroendocrine tumor and (16) poorly differentiated neuroendocrine carcinoma, and (17) the distinction of well-differentiated neuroendocrine tumor G3 from poorly differentiated neuroendocrine carcinoma; it concludes with (18) a discussion of diagnostic considerations in the broad-spectrum keratin/CD45/S-100-"triple-negative" neoplasm.

Role of Ancillary Techniques in Fluid Cytology

The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.

Management of cytological material, pre-analytical procedures and bio-banking in effusion cytopathology

Serous effusion fluid is one of the most commonly encountered specimens in routine cytopathology practice. It provides invaluable information about the patient and the clinical status; but to get the most of it, specimen handling and processing must be carried out properly. Cytomorphology is the basis of a successful analysis which should complemented by ancillary tests when needed. A wide spectrum of ancillary techniques - ranging from immunocytochemistry and flow cytometry to different assays of molecular pathology - can be applied to serous effusions. This article describes the acquisition and management of serous effusion fluids, methods for preservation and transportation, different techniques of cytopreparation, application of immunocytochemistry, flow cytometry, and fluorescence in-situ hybridization (FISH), as well as DNA extraction for polymerase chain reaction (PCR) and next generation sequencing (NGS). Principles of bio-banking of effusion samples are also discussed which is getting more important in correlation with the developments in personalized medicine.

Polymorphism in lncRNA AC016683.6 and its interaction with smoking exposure on the susceptibility of lung cancer

Background

Long non-coding RNAs play pivotal roles in the carcinogenesis of multiple types of cancers. This study is firstly to evaluate influence of rs4848320 and rs1110839 polymorphisms in long non-coding RNA AC016683.6 on the susceptibility of lung cancer.

Methods

The present study was a hospital-based case–control study with 434 lung cancer patients and 593 cancer-free controls. Genotyping of the two SNPs detected by Taqman^® allelic discrimination method.

Results

There were no statistically significant associations between rs4848320 and rs1110839 polymorphisms in AC016683.6 and risk of lung cancer in overall population. However, in the smoking population, rs4848320 and rs1110839 polymorphisms significantly increased the risk of lung cancer in dominant and homozygous models (Rs4848320: P = 0.029; Rs1110839: P = 0.034), respectively. In male population, rs1110839 genetic variant was related to the risk of lung cancer in all genetic models (GG vs. TT: P = 0.008; Dominant model: P = 0.029; Recessive model: P = 0.027) rather than heterozygous model. The crossover analyses provided rs4848320 and rs1110839 risk genotypes carriers combined with smoking exposure 2.218-fold, 1.755-fold increased risk of lung cancer (Rs4848320: P = 0.005; Rs1110839: P = 0.017). Additionally, there were significantly positive multiplicative interaction of rs4848320 polymorphism with smoking status, with adjusted OR of 2.244 (1.162–4.334), but rs1110839 polymorphism did not exist.

Conclusions

Rs4848320 and rs1110839 polymorphisms may be associated with lung cancer susceptibility. Interaction of rs4848320 risk genotypes with smoking exposure may strengthen the risk effect on lung cancer.

Genome-wide analysis of differentially expressed lncRNAs and mRNAs in primary gonadotrophin adenomas by RNA-seq

Recently, long non-coding RNAs (lncRNAs) have received increased research interest owing to their participation via distinct mechanisms in the biological processes of nonfunctional pituitary adenomas. However, changes in the expression of lncRNAs in gonadotrophin adenoma, which is the most common nonfunctional pituitary adenomas, have not yet been reported. In this study, we performed a genome-wide analysis of lncRNAs and mRNAs obtained from gonadotrophin adenoma patients’ samples and normal pituitary tissues using RNA-seq. The differentially expressed lncRNAs and mRNAs were identified using fold-change filtering. We identified 839 lncRNAs and 1015 mRNAs as differentially expressed. Gene Ontology analysis indicated that the biological functions of differentially expressed mRNAs were related to transcription regulator activity and basic metabolic processes. Ingenuity Pathway Analysis was performed to identify 64 canonical pathways that were significantly enriched in the tumor samples. Furthermore, to investigate the potential regulatory roles of the differentially expressed lncRNAs on the mRNAs, we constructed general co-expression networks for 100 coding and 577 non-coding genes that showed significantly correlated expression patterns in tumor cohort. In particular, we built a special sub-network of co-expression involving 186 lncRNAs interacting with 15 key coding genes of the mTOR pathway, which might promote the pathogenesis of gonadotrophin tumor. This is the first study to explore the patterns of genome-wide lncRNAs expression and co-expression with mRNAs, which might contribute to the molecular pathogenesis of gonadotrophin adenoma.

Long non-coding RNAs on the stage of cervical cancer (Review)

Cervical cancer is one of most malignant gynecological tumors. However, effective means for diagnosing and treating cervical cancer have yet to be identified. A few decades ago, long non-coding RNAs (lncRNAs) were regarded as useless parts of the genome, however, increasing data have demonstrated the importance of lncRNAs in the diagnosis and treatment of cervical cancers. The aim of the present study is to summarize the role(s) of HOTAIR, MALAT1, CCAT2, SPRY4-IT1, RSU1P2, CCHE1, lncRNA-EBIC and PVT1. Approximately 14 lncRNAs are involved in cervical cancer and several important proteins, miRNAs and other molecules and play crucial roles in a few traditional signaling pathways that have been proven to be related to those lncRNAs. In conclusion, lncRNAs may be useful as exact treatment targets and diagnostic biomarkers for improving therapies in cervical cancer patients and lncRNAs may contribute to effective diagnosis and treatment methods for cervical cancer.

Utility of GATA-3 in the work-Up of breast adenocarcinoma and its differential diagnosis in serous effusions:: A Cell-Block Microarray Study

BACKGROUND

GATA-3 is a transcription factor involved in human tissue growth and differentiation. It is a potential marker for breast carcinoma origin in metastasis and predictive of good prognosis. We aim to evaluate the role of GATA3 in determining the breast origin of metastatic adenocarcinoma in malignant effusions using immunohistochemistry on cell-block microarray in comparison with ER and PR results.

METHODS

Cell blocks from 100 cases of malignant and reactive serous effusions with confirmed diagnosis were selected; 28 mammary carcinomas, 64 extra-mammary adenocarcinomas (gastrointestinal, pulmonary, gynecologic), and 8 reactive mesothelium proliferation as control. Immunohistochemistry on cell-block microarray was used. Microarray slides were stained for GATA-3, ER and PR. Nuclear staining of >1% was considered positive.

RESULTS

GATA3, ER and PR were positive in 25 (89%), 20 (71%) and 16 (57%) of breast carcinoma cases, respectively. All non-breast cancer cases were negative for GATA-3 with the exception of one Müllerian adenocarcinoma (1.6%). The calculated sensitivity, specificity and positive predictive value (PPV) of GATA3 reactivity in determining the breast origin of metastatic adenocarcinoma was 89.3% (95% CI: 71.7-97.7%), 98.6% (95% CI: 91.6-99.9%) and 96.2% (95% CI: 80.4-99.9%), respectively. GATA3 positivity was associated with ER or PR positivity in 84% of cases.

CONCLUSIONS

GATA3 is a useful marker in determining the breast origin of metastatic adenocarcinoma in malignant serous effusions. Reactivity to GATA3 may indicate good prognosis. Diagn. Cytopathol. 2016;44:731-736. © 2016 Wiley Periodicals, Inc.

Can We Identify Nephrogenic Adenoma in Urine Cytology Specimens? A Study Evaluating Previously Described Cytomorphologic Features in Correlation With PAX8 Immunohistochemical Staining Results

OBJECTIVES

The aim of this study is to determine if the diagnosis of nephrogenic adenoma (NA) can be made on cytologic criteria alone and if pair box gene transcription factor 8 (PAX8) is useful in the diagnosis of NA in daily cytology practice.

METHODS

Cytologic features of NA previously described in a literature were used to identify NA cells in urinary specimens. Subsequently, all cytology and corresponding biopsy specimens were stained with the PAX8 immunohistochemistry stain. The stains were examined; the results were tabulated.

RESULTS

A total of 44 specimens were reviewed (35 with corresponding biopsy specimens diagnosed as NA and nine negative for NA diagnosis on corresponding biopsy specimens). Of them, 14 demonstrated features previously described as NA. None of atypical cells that were morphologically suspicious for NA showed positive staining, whereas all of the corresponding biopsy sections demonstrated nuclear PAX8 positivity. Only rare lymphocytes present in cytology specimens showed nuclear staining with PAX8.

CONCLUSIONS

Assuming that the results of the PAX8 stain performed are accurate at least in most cases, as suggested by the presence of internal positive controls, our study shows that the previously described cytologic features of NA cannot be used as diagnostic criteria, since they are not characteristic for this entity.

Clinically occult primary fallopian tube carcinoma presenting as a malignant pleural effusion

We report the first known case of malignant pleural effusion (MPE) as the sole presenting feature of clinically occult primary fallopian tube carcinoma (PFTC). A 57-year-old healthy woman was admitted with dyspnea. Evaluation demonstrated a right pleural effusion, fluid of which was malignant. The immunohistochemical profile, including negative calretinin, favored metastatic adenocarcinoma over mesothelioma but could not identify the primary tumour site. Pleural biopsy was not pursued as it would not have helped localize the primary. Chest, abdomen and pelvic computed tomography (CT) demonstrated only borderline lymphadenopathy in the left para-aortic lymph node chain that was hypermetabolic on positron emission tomography. Ultrasound and CT showed normal adnexal anatomy. These findings, coupled with an elevated serum CA-125, prompted empiric neoadjuvant chemotherapy targeting epithelial ovarian carcinoma (EOC) followed by surgery, which revealed a tiny left PFTC with negative peritoneal washings. Sampled left para-aortic lymph nodes were positive. The pleural effusion resolved after chemotherapy. Malignant pleural disease without peritoneal involvement is more characteristic of PFTC than of EOC, in which MPE is common but almost always accompanies peritoneal carcinomatosis. The extensive lymphatic supply of the fallopian tube promotes distant metastasis of small, seemingly localized tumours. This case is a reminder that the clinician should not be dissuaded from considering carcinoma of Müllerian origin, especially PFTC, as the cause of a MPE even in the face of normal gynecologic imaging. Appropriately broad immunohistochemical staining and careful attention to even minimal lymphadenopathy can be invaluable in pinpointing the primary tumour site in such patients.