Aparna Mahajan

HMGA2: A biomarker significantly overexpressed in high-grade ovarian serous carcinoma

Ovarian carcinoma consists of a group of histologically heterogeneous diseases involving distinct tumorigenic pathways. High-grade papillary serous carcinoma of the ovary is commonly associated with p53 mutations. HMGA2, an oncofetal protein, is found to be overexpressed in ovarian cancer. To study the function of HMGA2 in ovarian cancer, it is important to know which subtypes of ovarian cancer are associated with HMGA2 overexpression. In this study, we collected six different types of ovarian cancer and examined HMGA2 expression by immunohistochemistry, along with HMGA1, p53 and Ki-67. We found that HMGA2 overexpression was significantly higher in high-grade papillary serous carcinoma (64%) and carcinosarcoma (60%) than in other types of ovarian cancers (7–23%). HMGA2 overexpression was moderately associated with dominant p53 mutations (R=0.51). In addition, the microRNA in situ analysis revealed that let-7b, the HMGA2-negative regulators, were significantly lost in high-grade serous carcinoma. Our findings suggest that HMGA2 is an important molecular change significantly related to high-grade papillary serous carcinoma and is less common in other histological types of ovarian cancer.

Thyroid Bethesda reporting category, 'suspicious for papillary thyroid carcinoma', pitfalls and clues to optimize the use of this category.

A. Mahajan, X. Lin and R. Nayar

Practical issues in the application of p16 immunohistochemistry in diagnostic pathology.

The p16 tumor suppressor gene (CDKN2A) is a member of the INK4 class of cell cycle inhibitors and is located on chromosome 9p21. The p16 protein binds to cyclin-dependent kinases 4 and 6 and maintains the retinoblastoma gene product in its hypophosphorylated state, which in turn binds to E2F transcription factor and prevents cell cycle progression. Expression of p16 protein is increased in aging cells. Immunohistochemistry for p16ink4a is most widely used as a surrogate maker for high-risk human papilloma virus infection in formalin-fixed, paraffin-embedded tissues. The most widely researched, accepted, and practiced use of p16 immunostain is in the lower anogenital tract. In addition, p16 immunostain is widely used for oropharyngeal squamous cell carcinoma. Its applications have also been extended to gynecologic tumors, which are unrelated to human papillomavirus. This article aims to review the literature on the diagnostic utility of p16 immunohistochemistry and highlight the practical issues in the application and interpretation of this stain.

Cholangiocarcinoma Presenting as Metastases to the Cervical Spine

0002-9343/

Touch preparation of jumbo forceps biopsies allows rapid adequacy assessment of subepithelial GI masses

-see front matter

Differential CARM1 Isoform Expression in Subcellular Compartments and among Malignant and Benign Breast Tumors.

f v T l c c U l w ( u H s l c A o n o a p s a q n w Subepithelial mass lesions are detected frequently during clinical care, often incidentally seen in the stomach during endoscopy performed for other indications. Alteratively, they may be seen on radiographic imaging or ecause of symptoms. Evaluation of these lesions may be hallenging because superficial biopsies will rarely be iagnostic. After evaluation of these lesions with EUS to haracterize their layer of origin, tissue acquisition is often erformed. There are multiple modalities to sample these lesions, ncluding EUS-guided FNA (EUS-FNA), EUS-guided core eedle biopsy, bite-on-bite forceps biopsies, and endocopic resection.2 EUS-FNA cytology alone may be inadequate or inaccurate in nearly half of these patients.3-5 Although EUS-guided core needle biopsy is intended to provide histology, the rigid needle can be difficult to use and does not reliably obtain tissue and, thus, may be inadequate.6 For lesions that create an impression on the astric lumen, bite-on-bite forceps biopsies by using umbo forceps allow the creation of a tunnel through the ucosa into the underlying lesion.7 However, for deep lesions, it may be unclear whether adequate tissue has been obtained, in contrast to EUS-FNA, in which on-site cytology is often used. In this study, we describe our results with using the bite-on-bite technique with jumbo forceps and touch-

Multinucleation is an objective feature useful in the diagnosis of pleomorphic lobular carcinoma in situ.

Purpose Coactivator-associated arginine methyltransferase 1 (CARM1) is a coactivator for ERα and cancer-relevant transcription factors, and can methylate diverse cellular targets including histones. CARM1 is expressed in one of two alternative splice isoforms, full-length CARM1 (CARM1FL) and truncated CARM1 (CARM1ΔE15). CARM1FL and CARM1ΔE15 function differently in transcriptional regulation, protein methylation, and mediation of pre-mRNA splicing in cellular models. Methods To investigate the functional roles and the prognosis potential of CARM1 alternative spliced isoforms in breast cancer, we used recently developed antibodies to detect differential CARM1 isoform expression in subcellular compartments and among malignant and benign breast tumors. Results Immunofluorescence in MDA-MB-231 and BG-1 cell lines demonstrated that CARM1ΔE15 is the dominant isoform expressed in the cytoplasm, and CARM1FL is more nuclear localized. CARM1ΔE15 was found to be more sensitive to Hsp90 inhibition than CARM1FL, indicating that the truncated isoform may be the oncogenic form. Clinical cancer samples did not have significantly higher expression of CARM1FL or CARM1ΔE15 than benign breast samples at the level of mRNA or histology. Furthermore neither CARM1FL nor CARM1ΔE15 expression correlated with breast cancer molecular subtypes, tumor size, or lymph node involvement. Conclusions The analysis presented here lends new insights into the possible oncogenic role of CARM1ΔE15. This study also demonstrates no obvious association of CARM1 isoform expression and clinical correlates in breast cancer. Recent studies, however, have shown that CARM1 expression correlates with poor prognosis, indicating a need for further studies of both CARM1 isoforms in a large cohort of breast cancer specimens.

Sensitivity and Isoform Specificity of18F-Fluorofuranylnorprogesterone for Measuring Progesterone Receptor Protein Response to Estradiol Challenge in Breast Cancer

OBJECTIVESnBi- and multinucleated (B/M) cells are present in a variety of tumors. We evaluated lobular carcinoma in situ (classic and pleomorphic types) and ductal carcinoma in situ (DCIS) to determine if this objective morphologic feature aids the differential diagnosis.nnnMETHODSnThe number of B/M cells was recorded in pleomorphic lobular carcinoma in situ (PLCIS) (n = 20), classic lobular carcinoma in situ (CLCIS) (n = 26), and DCIS (n = 37).nnnRESULTSnBinucleated cells were significantly more frequent in PLCIS (100%) vs DCIS (43%; P < .0001) and CLCIS (54%; P = .0004). Multinucleated cells were present in 25% of PLCIS cases and 8% of DCIS cases, and they were absent in CLCIS. The quantity of B/M per high-power field (hpf) was less in DCIS (mean, 1.1) and CLCIS (mean, 2.5) compared with PLCIS (mean, 5.8). Thirty-five percent of PLCIS cases had more than five B/M per hpf.nnnCONCLUSIONSnBinucleated cells are significantly more frequent in PLCIS vs CLCIS and DCIS. Multinucleated cells were never identified in CLCIS. PLCIS should be considered as a diagnosis when B/M is noted.

Psychological aspects of utilizing telecytology for rapid on-site adequacy assessments

The purpose of this study was to evaluate the ability of 21-18F-fluoro-16α,17α-[(R)-(1′-α-furylmethylidene)dioxy]-19-norpregn-4-ene-3,20-dione (18F-FFNP) to measure alterations in progesterone receptor (PR) protein level and isoform expression in response to 17β-estradiol (E2) challenge. Methods: T47D human breast cancer cells and female mice bearing T47D tumor xenografts were treated with E2 to increase PR expression. 18F-FFNP uptake was measured using cell uptake and tissue biodistribution assays. MDA-MB-231 breast cancer clonal cell lines were generated that express the A or B isoform of human PR. PR protein levels, transcriptional function, and subcellular localization were determined. In vitro 18F-FFNP binding was measured via saturation and competitive binding curves. In vivo 18F-FFNP uptake was measured using tumor xenografts and PET. Statistical significance was determined using ANOVA and t tests. Results: After 48 and 72 h of E2, 18F-FFNP uptake in T47D cells was maximally increased compared with both vehicle and 24 h of E2 treatment (P < 0.0001 vs. ethanol; P = 0.02 and P = 0.0002 vs. 24 h for 48 and 72 h, respectively). T47D tumor xenografts in mice treated with 72 h of E2 had maximal 18F-FFNP uptake compared with ethanol-treated mice (percentage injected dose per gram: 11.3 ± 1.4 vs. 5.2 ± 0.81, P = 0.002). Corresponding tumor-to-muscle uptake ratios were 4.1 ± 0.6, 3.9 ± 0.5, and 2.3 ± 0.4 for 48 h of E2, 72 h of E2, and ethanol-treated mice, respectively. There was no significant preferential 18F-FFNP binding or uptake by PR-A versus PR-B in the PR isoform–specific cell lines and tumor xenografts. Conclusion: 18F-FFNP is capable of measuring estrogen-induced shifts in total PR expression in human breast cancer cells and tumor xenografts, with equivalent isoform binding.

Sex as a Biological Variable in Preclinical Imaging Research: Initial Observations with 18F-Fluorothymidine

Rapid On-Site Evaluation (ROSE) has been well documented in its ability to improve the diagnostic yield and accuracy of fine needle aspirations across many sites, resulting in better quality of patient management and a simultaneous reduction in treatment costs. Telecytology makes it possible for cytology laboratories to offer ROSE in a cost effective manner, whilst employing only a small number of trained cytopathologists to cover many sites from a single connected location. However, the adoption of telecytology for ROSE has been lackluster. We believe that this reluctance is not only due to barriers such as technology limitations and financial obstacles, but also due to overlooked psychological factors. This article discusses the unaddressed psychological considerations of telecytology for ROSE.