Denise Frias-Hidvegi

Detection of numerical chromosomal abnormalities by fluorescence in situ hybridization of interphase cell nuclei with chromosome-specific probes on archival cytologic samples

Fluorescence in situ hybridization (FISH) is rapidly emerging as a tool for analyzing numerical and structural chromosomal abnormalities in both liquid and solid tumors. Most studies make use of fresh samples. To determine the feasibility of detecting numerical chromosomal abnormalities (NCA) by FISH using chromosome‐specific probes 8, 12, 17, and X (Vysis, Inc., Downers Grove, IL) on archival cytologic preparations, we studied 23 patient samples, one Papanicolaou‐ and one Diff‐Quik‐stained slide per case (46 slides), and two additional unstained slides (fresh ascitic fluids) as controls. Included in this study were nine ascitic fluids (four benign and five malignant), four malignant pleural fluids, three benign bladder washes, and seven malignant fine‐needle aspirates (FNA) from various sites. The slides ranged from 1–94 days old. After removal of coverslips using xylene, all slides were destained in a series of alcohol and water washes. Pretreatment of slides with pepsin was followed by the in situ hybridization procedure. Two hundred cells per slide were evaluated for distinct separate signals. Results showed the following: 1) all slides were evaluable except for eight (8/46) which had either too few cells or enough cells but with faint signals, 2) the oldest sample showed distinct signals, 3) previously Diff‐Quik‐stained slides showed relatively better signals than Papanicolaou‐stained slides, 4) samples less than a month old showed relatively better signals, and 5) malignant samples showed various NCA, but not the benign samples. We conclude that FISH on archival cytologic preparation 1) is feasible, although age of the slide is a factor since better signals were seen in those less than a month old, 2) shows better results in previously Diff‐Quik‐stained slides, and 3) is a tool that can be used in the retrospective study of various liquid and solid neoplasms. Diagn Cytopathol 1996;14:178–181.

Diagnostic significance of signet ring cells in fine-needle aspirates of the breast.

Fine‐needle aspiration (FNA) is a reliable and cost‐effective procedure in the evaluation and management of breast lesions. One diagnostic dilemma that may sometimes arise is the finding of signet ring cells. The isolated finding of such cells in aspirate smears may be particularly problematic in cases of low cellularity or those with otherwise benign features. Although it is generally held that such cells are almost exclusively associated with carcinoma (particularly the lobular subtype), their significance in FNA smears has never been systematically evaluated. To establish their diagnostic utility, we evaluated aspirate smears from 150 cases of histologically proven benign (77) and malignant (73) breast lesions for the presence of signet ring cells, defined as those containing a prominent intracytoplasmic vacuole with nuclear displacement. Signet ring cells were identified in 71% of malignant cases (75% of ductal carcinomas and 71% of lobular carcinomas), mostly as single cells or within small, loosely cohesive tissue fragments. Such cells were also present in 6% of histologically proven benign lesions, most commonly within large tissue fragments. Many of these cells were proven to be vacuolated myoepithelial cells, based on histologic correlation and immunostaining results using anti‐muscle‐specific actin. On the basis of these findings, we conclude that (1) the presence of signet ring cells within small loose tissue fragments or as single cells in FNA smears should prompt close clinical follow‐up (including repeat FNA and perhaps surgical biopsy), regardless of smear cellularity, (2) the presence of signet ring cells in cases of adenocarcinoma does not predict a particular tumor subtype, and (3) rare benign breast lesions may contain signet ring cells, particularly within large tissue fragments, and do not, in isolation, warrant surgical biopsy to exclude malignancy. Diagn. Cytopathol. 16:117–121, 1997.

Cytomorphology of primary CNS lymphoma: review of 23 cases and evidence for the role of EBV.

Primary non‐Hodgkins lymphoma of the central nervous system (PCNSL) has recently increased in incidence, due primarily to an enlarging immunosuppressed patient population. The pathogenetic role of Epstein‐Barr virus (EBV) is of interest due to its established role in other lymphoproliferative disorders in immunosuppressed patients. Twenty‐three cases of histologically confirmed PCNSL with corresponding cytology were identified, all obtained under stereotactic guidance. Twenty patients were human immunodeficiency virus (HIV) positive, two were HIV negative, and one was of unknown status. Papanicolaou‐stained slides were selected from each case and evaluated for the presence of EBV RNA via in situ hybridization (ISH) utilizing a biotinylated probe specific for EBER 1 RNA, and detected by a conventional streptavidin‐peroxidase system. The cases included immunoblastic (12), large cell (10), and mixed small and large cell lymphoma (1). The predominant immunophenotype was B‐cell (19), although T‐cell (2) and biphenotypic (1) cases were also identified. ISH showed nuclear positivity for EBV RNA in 19 of 23 cases (83%). This study confirms the presence of EBV in PCNSL in immunosuppressed patients and implies a potential etiologic role. The ability to demonstrate EBV RNA in cytologic preparations by ISH also raises the possibility of early identification of high‐risk patients through detection of EBV‐infected lymphocytes in CSF specimens. Diagn Cytopathol 1996; 14:114–120.

Intraoperative Diagnostic Techniques for Stereotactic Brain Biopsy: Cytology versus Frozen-Section Histopathology

Stereotactic brain biopsy has gained widespread acceptance as a primary diagnostic tool for the evaluation of intracranial lesions. Intraoperative evaluation of such specimens has included the use of both cytological and frozen section histologic techniques. The current study seeks to compare the diagnostic utility of frozen section histopathology and cytology in the intraoperative evaluation of stereotactic brain biopsies in HIV-seropositive patients. Seventy-five HIV-seropositive patients undergoing stereotactic brain biopsy for the evaluation of intracranial lesions were evaluated; intracranial diseases were predominantly infectious or hematologic malignancies. Comparison of frozen section and cytology as a means of intraoperative evaluation showed cytology to have a greater sensitivity (86 vs. 78%), positive (95 vs. 90%) and negative (50 vs. 39%) predictive values and a greater overall diagnostic efficiency (84 vs. 75%) than frozen section. Thus, cytology is a highly effective tool equaling and in some cases surpassing frozen section in terms of sensitivity, predictive value, and overall accuracy. Cytologic examination may often be used as the sole means of intraoperative diagnosis, obviating the need for the freezing and sectioning of fresh tissue and potentially reducing specimen turn around time as well. In other cases, cytology can be used in conjunction with other methodologies for arriving at both intraoperative and final diagnoses in these often difficult cases.

Cytologic Grading of Fine Needle Aspirates of Breast Carcinoma by Private Practice Pathologists

OBJECTIVE To determine the reproducibility of two clinically proven grading systems for breast carcinoma assessed by private practice pathologists. STUDY DESIGN Twenty fine needle aspiration (FNA) slides of histologically proven breast carcinoma were submitted to 15 private practice pathologists practicing in 11 separate groups who interpret cytology as part of their daily practice. The pathologists received the same set of slides. They graded the FNAs using the modified Black (MB) (grades 1-3) and simplified Black (SB) (low grade, high grade) grading systems. Specified criteria and guidelines as well as case samples were provided. RESULTS There was complete agreement among the 15 pathologists on only one case using the MB grading system as compared to five using the SB grading system. In MB, > or = 10 pathologists were in agreement on 14 cases as compared to 19 cases using SB. There were three cases in MB where the grades ranged from 1 to 3. Also noted in MB was the high number of cases graded 2 (intermediate grade). The predominant comment made by the pathologists was the easier, more objective and practical application of the SB. CONCLUSION High reproducibility in the cytologic grading of FNA of breast carcinoma can be more readily attained among private practice pathologists using the two-tier SB grading system.