Sara E. Monaco

The Diagnostic Utility of p16 FISH and GLUT-1 Immunohistochemical Analysis in Mesothelial Proliferations

Two promising ancillary tests used in the diagnosis of mesothelioma include GLUT-1 immunohistochemical analysis and fluorescence in situ hybridization (FISH) testing for the p16 deletion. This study compared the diagnostic usefulness of p16 FISH and GLUT-1 immunohistochemical analysis in the diagnosis of mesothelial proliferations in 158 cases with a diagnosis of benign (45.4%), atypical (10.4%), or malignant/mesothelioma (44.2%). Of the 70 benign cases, none had a deletion of p16 and 5 cases (7%) were positive for GLUT-1. Of the 68 mesotheliomas, 40 (59%) had a deletion of p16 (sensitivity, 59%; specificity, 100%) and 27 (40%) were positive for GLUT-1 (sensitivity, 40%; specificity, 93%). GLUT-1 showed lower sensitivity in pleural (56% vs 70%) and peritoneal (29% vs 51%) mesotheliomas (P = .004). Our results demonstrate that p16 FISH is a more sensitive and specific test than GLUT-1 immunohistochemical analysis and can be a more reliable ancillary tool to support the diagnosis of mesothelioma.

A comparison of EGFR and KRAS status in primary lung carcinoma and matched metastases.

Epidermal growth factor receptor (EGFR) and v-Ki-ras 2 (KRAS; viral Kirsten rat sacoma 2 oncogene homolog) oncogenes are predictors of response to EGFR-targeted therapy in lung carcinomas. Morphologic heterogeneity of lung carcinomas is reflected at the molecular level and may confound interpretation of immunohistochemistry, fluorescence in situ hybridization, and mutational assays, which are all used for analysis of KRAS and EGFR genes. Furthermore, molecular characteristics may differ between the primary tumor and corresponding metastases. The aim of this study was to determine if the KRAS and/or EGFR status of primary and metastatic lung carcinoma differs. Three hundred thirty-six cases of primary lung carcinomas were tested for EGFR and KRAS, and 85 cases had a metastasis (25%). Of the 40 cases (47%) with sufficient material for EGFR and KRAS mutational analysis, there were 11 (27.5%) primary tumors and 4 (10%) metastases identified with a KRAS mutation. Of the cases with EGFR fluorescence in situ hybridization results, there were 3 (8%) primary tumors and 8 (24%) metastases that were fluorescence in situ hybridization positive. Overall, there were 9 cases (22.5%) with discordant KRAS status and 11 cases (32.5%) with discordant EGFR fluorescence in situ hybridization status. Our results suggest that the EGFR and KRAS status of primary lung carcinomas may not predict the status in the corresponding metastases. This observation may have important implications for molecular testing for targeted therapies.

Indeterminate Pediatric Thyroid Fine Needle Aspirations: A Study of 68 Cases

Objective: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) provides a reporting scheme for thyroid fine needle aspiration (FNA) and includes three indeterminate categories with different management strategies. This study analyzes indeterminate thyroid FNAs in children, and correlates these findings with the histological features. Methods: A total of 179 thyroid FNA specimens were retrieved from children. Cases were categorized by TBSRTC. Only cases diagnosed as atypia (AUS)/follicular lesion of undetermined significance (FLUS), suspicious for follicular or oncocytic neoplasm (SFON), or suspicious for malignancy (SM) were selected and correlated with the nodule size and histological follow-up. Results: Sixty-eight cases were identified, including 43 (63%) AUS/FLUS diagnoses, 19 (28%) SFON, and 6 (9%) SM. On follow-up, 48% were malignant, including 28% AUS/FLUS cases, 58% SFON, and 100% SM. The average size of the malignant lesions diagnosed preoperatively as AUS/FLUS was 1.5 cm (range 0.7-4.5), compared to 3.3 cm (range 1.2-6.6) in SFON and 2.8 cm (range 0.7-3.8) in SM. Malignancies included 92% papillary thyroid carcinoma (PTC), 77% of which were the follicular variant of PTC (FVPTC) and 8% follicular carcinomas. The AUS/FLUS cases were largely due to compromised specimens (49%) and the highest malignancy rate occurred in those with cytological atypia (50%). Conclusions: This study shows an incremental risk of malignancy within the indeterminate categories using TBSRTC in children. Malignant nodules with a preoperative AUS/FLUS diagnosis tended to be smaller than those with a SFON or SM diagnosis, and the vast majority of malignancies were PTC, with a high proportion being FVPTC.

The state of cell block variation and satisfaction in the era of molecular diagnostics and personalized medicine.

Background: In the recent past, algorithms and recommendations to standardize the morphological, immunohistochemical and molecular classification of lung cancers on cytology specimens have been proposed, and several organizations have recommended cell blocks (CBs) as the preferred modality for molecular testing. Based on the literature, there are several different techniques available for CB preparation-suggesting that there is no standard. The aim of this study was to conduct a survey of CB preparation techniques utilized in various practice settings and analyze current issues, if any. Materials and Methods: A single E-mail with a link to an electronic survey was distributed to members of the American Society of Cytopathology and other pathologists. Questions pertaining to the participants’ practice setting and CBs-volume, method, quality and satisfaction-were included. Results: Of 95 respondents, 90/95 (94%) completed the survey and comprise the study group. Most participants practice in a community hospital/private practice (44%) or academic center (41%). On average, 14 CBs (range 0-50; median 10) are prepared by a laboratory daily. Over 10 methods are utilized: Plasma thrombin (33%), HistoGel (27%), Cellient automated cell block system (8%) and others (31%) respectively. Forty of 90 (44%) respondents are either unsatisfied or sometimes satisfied with their CB quality, with low-cellular yield being the leading cause of dissatisfaction. There was no statistical significance between the three most common CB preparation methods and satisfaction with quality. Discussion: Many are dissatisfied with their current method of CB preparation, and there is no consistent method to prepare CBs. In todays era of personalized medicine with an increasing array of molecular tests being applied to cytological specimens, there is a need for a standardized protocol for CB optimization to enhance cellularity.

Diagnostic difficulties and pitfalls in rapid on-site evaluation of endobronchial ultrasound guided fine needle aspiration.

Background: One of the novel techniques utilizing fine needle aspiration (FNA) in the diagnosis of mediastinal and lung lesions is the endobronchial ultrasound (EBUS)-guided FNA. In this study, we describe five cases which had a discrepancy between on-site evaluation and final diagnosis, or a diagnostic dilemma when rendering the preliminary diagnosis, in order to illustrate some of the diagnostic difficulties and pitfalls that can occur in EBUS FNA. Methods: A total of five EBUS FNA cases from five patients were identified in our records with a discrepancy between the rapid on-site evaluation (ROSE) and final diagnosis, or that addressed a diagnostic dilemma. All of the cases had histological confirmation or follow-up. The cytomorphology in the direct smears, cell block, and immunohistochemical stains were reviewed, along with the clinical history and other available information. Results: Two cases were identified with a nondefinitive diagnosis at ROSE that were later diagnosed as malignant (metastatic signet-ring cell adenocarcinoma and metastatic renal cell carcinoma (RCC)) on the final cytological diagnosis. Three additional cases were identified with a ROSE and final diagnosis of malignant (large cell neuroendocrine carcinoma (LCNEC) and two squamous cell carcinomas), but raised important diagnostic dilemmas. These cases highlight the importance of recognizing discohesive malignant cells and bland neoplasms on EBUS FNA, which may lead to a negative or a nondefinitive preliminary diagnosis. Neuroendocrine tumors can also be difficult due to the wide range of entities in the differential diagnosis, including benign lymphocytes, lymphomas, small and nonsmall cell carcinomas, and the lack of immunohistochemical stains at the time of ROSE. Finally, the background material in EBUS FNAs may be misleading and unrelated to the cells of interest. Conclusions: This study illustrates the cytomorphology of five EBUS FNA cases that address some of the diagnostic challenges witnessed while examining these specimens during ROSE. Many of the difficulties faced can be attributed to the baseline cellularity of the aspirates, the bronchial contamination, the difficulty identifying neoplasms with bland cytology, the wide spectrum of diseases that can occur in the mediastinum with overlapping cytomorphologic features, the mismatch between the background material and the cell populations present, and the overall unfamiliarity with these types of specimens.

Diagnostic accuracy and limitations of fine-needle aspiration cytology of bone and soft tissue lesions: a review of 1114 cases with cytological-histological correlation.

Fine‐needle aspiration (FNA) cytology is increasingly being used as a diagnostic modality for soft tissue and bone lesions. These diagnoses can be challenging because of a variety of factors, including interpretation and sampling issues. This study investigates the diagnostic utility of FNA biopsy, in addition to the diagnostic pitfalls, in soft tissue and bone cytopathology.

Insulin stimulates fibroblast proliferation through calcium-calmodulin-dependent kinase II

Insulin effects are mediated by multiple integrated signals generated by the insulin receptor. Fibroblasts, as most of mammalian cells, are a target of insulin action and are important actors in the vascular pathogenesis of hyperinsulinemia. A role for calcium-calmodulin-dependent kinases (CaMK) in insulin signalling has been proposed but has been under investigated. We investigated the role of the CaMK isoform II in insulin signalling in human fibroblasts. A rapid and transient increase of intracellular calcium concentration was induced by insulin stimulation, followed by increase of CaMKII activity, via L type calcium channels. Concomitantly, insulin stimulation induced Raf-1 and ERK activation, followed by thymidine uptake. Inhibition of CaMKII abrogated the insulin-induced Raf-1 and ERK activation, resulting also in the inhibition of thymidine incorporation. These results demonstrate that in fibroblasts, insulin-activated CaMKII is necessary, together with Raf-1, for ERK activation and cell proliferation. This represents a novel mechanism in the control of insulin signals leading to fibroblast proliferation, as well as a putative site for pharmacological intervention.

Evaluation of endobronchial ultrasound‐guided fine‐needle aspirations (EBUS‐FNA): Correlation with adequacy and histologic follow‐up

Endobronchial ultrasound‐guided fine‐needle aspiration (EBUS‐FNA) is a minimally invasive modality for diagnosing mediastinal lesions. When determining adequacy, EBUS‐FNAs are evaluated for diagnostic material or sufficient lymphoid tissue. In this study, the authors evaluated their experience with EBUS‐FNAs and correlated the findings with adequacy and histologic follow‐up.

Cytologic subtyping of lung adenocarcinoma by using the proposed International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) adenocarcinoma classification

The significance of histologic subtyping of surgically resected lung adenocarcinoma (ADC) was recently proposed by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification. Approximately 70% of lung cancer patients present with advanced disease, and small biopsies or cytology specimens are frequently the only available diagnostic material. It is uncertain whether proposed morphologic subtyping of ADC can be applied to small specimens. The objective of this study was to assess the applicability of morphologic subtyping of ADC on cytologic specimens.

Fluorescence In Situ Hybridization Studies on Direct Smears An Approach to Enhance the Fine-Needle Aspiration Biopsy Diagnosis of B-Cell Non-Hodgkin Lymphomas

In the fine‐needle aspiration biopsy (FNAB) diagnosis of B‐cell non‐Hodgkin lymphomas (B‐NHL), the role of flow cytometry (FC) can be limited because of nondiagnostic findings. Fluorescence in situ hybridization (FISH) studies, similar to FC, can be helpful in establishing clonality and in subclassifying the lymphoma. The aim of the current study was to determine whether FISH studies performed on unstained direct smears improved the ability to diagnose and/or subclassify B‐NHL on FNAB.