Sustained rescue of prefrontal circuit dysfunction by antidepressant-induced spine formation.

The neurobiological mechanisms underlying the induction and remission of depressive episodes over time are not well understood. Through repeated longitudinal imaging of medial prefrontal microcircuits in the living brain, we found that prefrontal spinogenesis plays a critical role in sustaining specific antidepressant behavioral effects and maintaining long-term behavioral remission. Depression-related behavior was associated with targeted, branch-specific elimination of postsynaptic dendritic spines on prefrontal projection neurons. Antidepressant-dose ketamine reversed these effects by selectively rescuing eliminated spines and restoring coordinated activity in multicellular ensembles that predict motivated escape behavior. Prefrontal spinogenesis was required for the long-term maintenance of antidepressant effects on motivated escape behavior but not for their initial induction.

Fine needle aspiration of gastrointestinal stromal tumors.

OBJECTIVE: Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal tumors of the gastrointestinal tract. Fine needle aspiration (FNA) is one option for diagnosing GISTs before surgery. This study was designed to evaluate the clinical utility of FNA in the diagnosis of GISTs. STUDY DESIGN: FNAs from 19 GISTs originating in the stomach, small bowel and colon obtained from 1988 to 1998 were studied. Immunocytochemistry was performed on 12 cases. The GISTs were classified as benign, borderline and malignant, according to location, size, mitotic activity and clinical outcome. RESULTS: Benign (three) and borderline (five) GISTs were all spindle cell type; malignant GISTs included five spindle cell type and six epithelioid type. Most smears contained abundant cellular material. Benign and borderline GISTs of spindle cell type tended to have cells arranged in tightly cohesive clusters, while malignant GISTs were more likely to exhibit loosely cohesive groups with many single cells, occasional nuclear pleomorphism, hyperchromasia and irregular nuclear contours. Epithelioid-type GISTs mimicked adenocarcinoma. Mitoses were seldom observed in either type. CD117 (KIT protein product) was demonstrated by immunocytochemistry in 9 cases, CD34 in 11, desmin in 3, S-100 protein in 2 and smooth muscle actin in 6 cases. CONCLUSION: FNA can be used to diagnose GISTs as spindle cell and epithelioid types, but cytomorphology alone cannot be used to assess malignant potential. Immunocytochemical staining for CD117 is helpful in confirming the diagnosis. Care must be taken to differentiate epithelioid-type GISTs from adenocarcinoma.

Telecytology: intraobserver and interobserver reproducibility in the diagnosis of cervical-vaginal smears.

Telecytologic diagnosis of cervical-vaginal smears is potentially useful because it could allow more efficient use of cytopathologist resources and expertise. A pathologist in one location could, in principle, review cytotechnologists' findings using a video display hundreds or thousands of miles away. Currently, bandwidth restrictions limit practical implementation of such a system to review of fields that had been selected for review by the cytotechnologist. The purpose of our investigation was to evaluate how well this type of review correlates with a review in which the entire slide is available for examination by the pathologist. We prospectively selected 100 consecutive cervical-vaginal smears over an 11-day period in August 1999. For each smear, 4 to 12 fields containing abnormal cells from each slide were digitally imaged. Each of 3 pathologists reviewed all digitized images and all glass slides. Diagnoses based on selected digitized images were compared with those based on conventional pathologist review. The kappa statistic, a measure of chance-corrected agreement (reproducibility), was calculated in each setting. Overall, intraobserver and interobserver reproducibility of cervical-vaginal smear diagnoses is fair to excellent. The use of remote digital images for pathologist review did not introduce large (2-step) diagnostic disagreements. The disagreement between a pathologist's glass slide and digital diagnoses is less than that for different pathologists reviewing glass slides, although interobserver differences were even greater in the interpretation of digital images.

Analysis of KIT mutation and protein expression in fine needle aspirates of gastrointestinal stromal/smooth muscle tumors.

OBJECTIVE: To determine if sequencing the KIT gene could facilitate more definitive FNA diagnosis. STUDY DESIGN: Sixteen cases of gastrointestinal stromal/smooth muscle tumor (GIST) in which fine needle aspiration (FNA) was performed (mean age, 67; M/F = 12/4) were studied. DNA was extracted from cytologic preparations from all patients (15 cell blocks, 1 alcohol-fixed smear) and seven subsequent resection specimens. DNA was amplified by polymerase chain reaction, using primers designed to amplify a segment of the KIT gene exon 11 and sequenced on an ABI Prism 377 DNA sequence analyzer (Applied Biosystems, Indianapolis, Indiana, U.S.A.). Immunocytochemical staining for CD 117 (the KIT gene product) was performed on sections from 12 cell blocks and 7 surgical resections. RESULTS: In-frame deletion of exon 11 was detected in eight cases (7 monoalleic, 1 bialleic); a point mutation was found in one case. Mutation was found only in histologically malignant (6 of 10 cases) and borderline GISTs (3 of 4 cases). No mutation was identified in benign tumors. In three cases, scant cellularity or blood precluded sequencing. CD 117 was expressed in 12 of 15 cases. CONCLUSION: Immunocytochemical staining for CD 117 is useful in confirming a cytologic diagnosis of GIST but does not facilitate diagnosis of malignancy. FNA biopsy specimens are suitable for KIT gene sequencing; detection of a KIT mutation favors a malignant diagnosis, though absence of mutation does not preclude malignancy.

Sampling, sampling errors and specimen preparation.

To obtain an adequate cervical smear for making a correct cytologic diagnosis, smear taking, laboratory handling and interpretation must be optimal. Many people are involved, and only by a combined effort of all links can this target be seriously approached: the smear takers will have to be open minded about technical improvements and read the morphologic descriptions cautiously; in the laboratory, cytotechnicians and physicians will have to challenge themselves and each other. It is mandatory to discard specimens that do not meet general standards of adequacy. At present a host of new techniques are being implemented. It is not feasible for all laboratories to be engaged in testing these new methods, but we are all requested to follow the development the best we can and switch to new ways when justified. Our working conditions are very different; therefore, it is our professional responsibility and plight to respond at the right time. So far the conclusion is that the conventional Pap smear is the international standard of care for the diagnosis of cervical cancer precursers in cancer screening programs. Certainly, this may change within a very short time. Liquid-based techniques, and in particular HPV technologies, are just around the corner.

Comparison of TriPath thin-layer technology with conventional methods on nongynecologic specimens.

OBJECTIVE: To evaluate the use of the TriPath PREP (previously called AutoCyte) TriPath Inc., Burlington, North Carolina, U.S.A.) in nongynecologic cytologic material by performing side-by-side comparison of conventional preparations with TriPath-prepared slides. STUDY DESIGN: An initial study of 613 cases (set A) was conducted to compare the TriPath PREP system with conventional methods for the evaluation of nongynecologic specimens, including urine, body cavity effusions, cerebrospinal fluid, pulmonary and gastrointestinal specimens. Paired cases were evaluated for cellularity, staining quality, preservation and representation of diagnostic material. Subsequent changes in the automated technique warranted reevaluation of the TriPath method. The follow-up study of 259 cases (set B) was conducted with the same design as set A. Results of evaluated parameters were analyzed using the chi 2 test. RESULTS: Results of the two sets were strikingly different. Prior to technical changes made by the laboratory, the TriPath method was significantly inferior. In the second set, the preferred material was most commonly the TriPath-prepared material. In particular, the majority of urine samples were prepared better by the automated, thin-layer system. CONCLUSION: The TriPath PREP system offers a reliable preparation of urine and has potential for other nongynecologic specimens, provided that careful attention is paid to technical details and some adjustments are made to account for specimen variability.

The accuracy of combined cytopathologic and flow cytometric analysis of fine-needle aspirates of lymph nodes.

We studied flow cytometry in 156 fine-needle aspirations (FNAs) of lymph nodes performed between June 1993 and September 1998. Information from flow cytometry was combined with cytomorphologic evaluation, and the diagnosis determined by using combined modalities was compared with tissue biopsy results or clinical follow-up. In 74 cases, a combined cytopathologic-flow cytometric diagnosis of lymphoma was made; histologic material was available for 52 patients; in no case was a benign process found. The lymphoma grade assigned agreed with histopathologic findings in 45 of 48 cases with a specific cytologic diagnosis. Treatment was initiated on the basis of the FNA alone for 17 of 52 patients with a history of lymphoma and in 22 additional patients with no follow-up biopsy. Among 71 cases in which the diagnosis using both modalities was benign, the only false-negative was 1 case of Hodgkin disease. Of the 156 cases, 11 were considered atypical or suggestive of lymphoma; biopsies from 8 of 10 patients revealed lymphoma. A combination of flow cytometry and cytomorphology of cells obtained by FNA of lymph nodes can distinguish between benign and malignant lymphoid infiltrates and support a diagnosis of lymphoma that permits definitive therapy in most cases.

Clinical significance of the qualification of atypical squamous cells of undetermined significance: An analysis on the basis of histologic diagnoses.

OBJECTIVE: This study was undertaken to evaluate the significance of further qualification of atypical squamous cells of undetermined significance in routine Papanicolaou smears. STUDY DESIGN: A retrospective medical records review was conducted on 316 women whose Papanicolaou smears yielded diagnoses of either atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion or atypical squamous cells of undetermined significance suggestive of a reactive process. RESULTS: The overall incidence of a squamous intraepithelial lesion (cervical intraepithelial neoplasia grades I, II, and III) was higher in the group with atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion than in the group with results suggestive of a reactive process (41.1% vs 22.3%; P =.0344). Women with atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion were 9.7 times more likely to have high-grade squamous intraepithelial lesion (cervical intraepithelial neoplasia III) develop than were women with atypical squamous cells of undetermined significance suggestive of a reactive process (95% confidence interval, 1.26-74.64). The incidence of high-grade squamous intraepithelial lesion was higher among women 35 years old (17.8% vs 6.3%; P =.0378). CONCLUSION: Women with a diagnosis of atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion are more likely to have intraepithelial lesions develop than are those with atypical squamous cells of undetermined significance suggestive of a reactive process. Aggressive evaluation of cases of atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion with colposcopy and cervical biopsies may be appropriate. Age should be considered as an independent factor in the plan of management.

Telecytologic diagnosis of breast fine needle aspiration biopsies. Intraobserver concordance.

OBJECTIVE: To determine the intraobserver concordance between telecytologic and glass slide diagnosis of breast fine needle aspirates. STUDY DESIGN: Twenty-five cases, originally received in consultation, were each examined by three cytopathologists. An average of seven compressed digital images per case were presented, together with a brief clinical history, using the http protocol and an internet browser. RESULTS: Agreement between the telecytologic and glass slide diagnosis ranged from 80% to 96%. Nevertheless, two cases that had been unequivocally diagnosed as malignant based upon video images were considered to be benign by the same pathologist when reviewing the glass slides. Both diagnostic confidence and self-concordance were higher for one pathologist having significant previous video microscopy experience. CONCLUSION: Although intraobserver concordance between telecytologic and glass slide diagnoses of breast fine needle aspirates is high, refinement of existing criteria for diagnosis of malignancy, taking account of the particular limitations associated with telecytologic diagnosis, may be prudent prior to widespread use of telecytology for fine needle aspiration evaluation.

Metastatic testicular Sertoli-cell tumor: cytopathologic findings on fine-needle aspiration.

Malignant Sertoli-cell tumors of the testis are exceedingly rare. We present cytopathologic findings in pelvic metastasis of such a tumor in a 45-year-old man, diagnosed on fine-needle aspiration, 2 months after radical orchiectomy. Ultrasound-guided aspirate showed tissue fragments and isolated discohesive tumor cells with characteristics of testicular Sertoli cells. Immunoperoxidase (IPOX) studies and histopathologic correlation with the primary testicular tumor are also presented. Cytopathologic features complimented by IPOX studies should allow an accurate diagnosis of this rare entity, when seen at metastatic sites.

ASCUS and AGUS criteria. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: The conference participants addressed the following issues: (1) reporting of equivocal diagnoses, (2) strategies to minimize the use of such diagnoses, (3) morphologic criteria, and (4) management of women with equivocal diagnoses. CONSENSUS POSITION: Equivocal diagnoses should be minimized, to the extent possible, by emphasizing cytologist education and training, improved specimen collection and quality assurance monitoring of individual and laboratory diagnosis rates. Cases fulfilling criteria for other diagnostic entities should not be included in the equivocal category. Regardless of the term utilized, an equivocal diagnosis should be qualified in some manner to indicate that the diagnosis defines a patient at increased risk of a lesion, particularly for those cases which raise concern about a possible high grade lesion. Qualification of an equivocal diagnosis can also be accomplished by appending laboratory statistics of the likelihood of various clinical outcomes or recommendations for patient follow-up. In contrast to favoring a reactive process versus squamous intraepithelial lesion (SIL), a more rationale approach to qualification of atypical squamous cells of undetermined significance may be to separate cases equivocal for low grade SIL from those suspicious for high grade SIL. With regard to glandular lesions, the conference participants expressed unanimous support for the separation of adenocarcinoma in situ (AIS) from atypical endocervical cells of undetermined significance when sufficient criteria are present. However, the diagnosis of a precursor lesion to AIS, endocervical glandular dysplasia, was controversial. The majority of conference participants discourage the use of such terms as mild glandular dysplasia and low grade glandular dysplasia for cytologic diagnoses. ONGOING ISSUES: Conference participants agreed that a term reflecting diagnostic uncertainty is necessary to communicate findings that are equivocal. However, participants could not agree on the wording of such a term. Opinions differed as to: (1) use of atypical, abnormal or morphologic changes to describe cell changes, (2) whether the diagnosis should indicate a squamous or glandular origin of the cells in question when this determination can be made, and (3) the value of defining morphologic criteria for such a diagnosis. The debate over terminology, as well as morphologic criteria, is ongoing, and the readership is invited to communicate opinions to Acta Cytologica. Management of women with equivocal diagnoses varies widely from locale to locale and may differ based on how the equivocal diagnosis is qualified. Findings insufficient for the diagnosis of a high grade lesion may warrant more aggressive follow-up than cases equivocal for a low grade lesion. Where sensitivity of detection of lesions is of paramount importance, follow-up will generally consist of more frequent cytology screening or colposcopy and biopsy. However, in some countries it is considered unethical to have a high percentage of false positive diagnoses, which result in overtreatment and an unnecessary burden for women participating in cervical screening. Future studies may provide a morphologic, or perhaps molecular, basis for distinguishing true precursors of neoplasia from minor lesions of no significant clinical import; this would allow a more coherent and rational approach to diagnosis and management of women with equivocal cytologic findings.

Medicolegal affairs. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Increasing litigation over alleged false negative cervical cytologic (CC) smears threatens the viability of this test for cervical cancer detection. The problem appears to be largely American but is beginning to appear in some other countries. In the vast majority of cases there is either a settlement or jury verdict for the plaintiff based largely on the testimony of expert witnesses. Cases are judged on an individual basis without significant consideration of the general performance of the CC smear in laboratories operating in compliance with a wide array of laboratory regulations and with documented and comprehensive quality control practices in place. It is acknowledged that there are problem laboratories and cytology practitioners. There is an emerging issue of automated preparation and screening devices and issues of informed patient consent. CONSENSUS POSITION: Cytology professionals have done an extraordinary and commendable job of educating the public about the benefits of the CC smear. We have been less successful and conscientious about explaining and defining the limitations of the CC test. There is a need for public and professional education as to the benefits and limitations of the CC smear for cervical cancer detection. The process suggested is to work with women's groups, public health agencies, government agencies, and state and national legislatures and to coordinate professional committees working on liability issues. Contextual information could be included with the CC smear report to indicate that a negative report confers a low probability of developing cervical cancer. It is suggested that appropriate language and a menu of statements be developed. Increased efforts should be directed to physician education with respect to informed consent concerning the benefits and limitations of CC smear testing and the application of new technology to improve smear accuracy. The process should include development of appropriate statements on the use of alternative technology. The profession should develop "process guidelines" for review of CC smears in the context of possible litigation, including standardized methods for blind slide review of smears that reduce or eliminate context and outcome bias. It is suggested that review panels be anonymous, that the process be standardized and that there be limitations on liability for participating organizations. Professional cytopathology and pathology societies should formulate acceptable guidelines for expert witnesses. The standards should be applicable to both defendant and plaintiff experts. All materials to the extent practical, including consultant opinions, should be available for peer review. Professional cytopathology and pathology societies should monitor expert testimony for objectivity and scientific accuracy. ONGOING ISSUES: For the near future, litigation will continue to focus on false negative CC smears on a case-by-case basis. Laboratories and individuals can reduce the risk of malpractice liability by directing their attention to proactive quality control and quality assurance methods. In the final analysis, consumer education about the benefits and limitations of the test is key to limiting malpractice claims. To stem the tide of continued medicolegal challenges to the integrity of cytology practice, the cytology community has now focused its efforts on developing and utilizing standards that convey to patients, attorneys and cytologists the contemporary status of and reasonable expectations for the practice of cytology. Guidelines such as those for uniform reporting terminology and clinical management of cervical abnormalities form the basis of cytology practice standards on which legal standards of practice can be based. Consensus conference reports, clinical management trials and scientifically valid studies of false negative rates that analyze the type, frequency and cause of missed cases represent sounder methods of establishing defensible

Computerized screening devices and performance assessment: development of a policy towards automation. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: The extension of automation to the diagnostic assessment of clinical materials raises issues of professional responsibility, on the part of both the medical professional and designer of the device. The International Academy of Cytology (IAC) and other professional cytology societies should develop a policy towards automation in the diagnostic assessment of clinical cytologic materials. CONSENSUS POSITION: The following summarizes the discussion of the initial position statement at the International Expert Conference on Diagnostic Cytology Towards the 21st Century, Hawaii, June 1997. 1. The professional in charge of a clinical cytopathology laboratory continues to bear the ultimate medical responsibility for diagnostic decisions made at the facility, whether automated devices are involved or not. 2. The introduction of automated procedures into clinical cytology should under no circumstances lead to a lowering of standards of performance. A prime objective of any guidelines should be to ensure that an automated procedure, in principle, does not expose any patient to new risks, nor should it increase already-existing, inherent risks. 3. Automated devices should provide capabilities for the medical professional to conduct periodic tests of the appropriate performance of the device. 4. Supervisory personnel should continue visual quality control screening of a certain percentage of slides dismissed at primary screening as within normal limits (WNL), even when automated procedures are employed in the laboratory. 5. Specifications for the design of primary screening devices for the detection of cervical cancer issued by the IAC in 1984 were reaffirmed. 6. The setting of numeric performance criteria is the proper charge of regulatory agencies, which also have the power of enforcement. 7. Human expert verification of results represents the "gold standard" at this time. Performance characteristics of computerized cytology devices should be determined by adherence to defined and well-considered protocols. Manufacturers should not claim a new standard of care; this is the responsibility of the medical community and professional groups. 8. Cytology professionals should support the development of procedures that bring about an improvement in diagnostic decision making. Advances in technology should be adopted if they can help solve problems in clinical cytology. The introduction of automated procedures into diagnostic decision making should take place strictly under the supervision and with the active participation and critical evaluation by the professional cytology community. ONGOING ISSUES: Guidelines should be developed for the communication of technical information about the performance of automated screening devices by the IAC to governmental agencies and national societies. Also, guidelines are necessary for the official communication of IAC concerns to industry, medicolegal entities and the media. Procedures and guidelines for the evaluation of studies pertaining to the performance of automated devices, performance metrics and definitions for evaluation criteria should be established.

Significant reduction in the rate of false-negative cervical smears with neural network-based technology (PAPNET Testing System).

False-negative cervical Pap smears may lead to disability or death from carcinoma of the uterine cervix. New computer technology has led to the development of an interactive, neural network-based vision instrument to increase the accuracy of cervical smear screening. The instrument belongs to a new class of medical devices designed to provide computer-aided diagnosis (CADx). To test the instrument's performance, 487 archival negative smears (index smears) from 228 women with biopsy-documented high-grade precancerous lesions or invasive cervical carcinoma (index women) were retrieved from the files of 10 participating laboratories that were using federally mandated quality assurance procedures. Samples of sequential negative smears (total 9,666) were retrieved as controls. The instrument was used to identify evidence of missed cytological abnormalities, including atypical squamous or glandular cells of undetermined significance (ASCUS, AGUS), low-grade or high-grade squamous intraepithelial lesions (LSIL, HSIL) and carcinoma. Using the instrument, 98 false-negative index smears were identified in 72 of the 228 index women (31.6%, 95% confidence interval [CI]: 25% to 38%). Disregarding the debatable categories of ASCUS or AGUS, there were 44 women whose false-negative smears disclosed squamous intraepithelial lesions (SIL) or carcinoma (19.3%; 95% CI: 14.2% to 24.4%). Unexpectedly, SILs were also identified in 127 of 9,666 control negative smears (1.3%; 95% CI: 1.1% to 1.5%). Compared with historical performance data from several participating laboratories, the instrument increased the detection rate of SILs in control smears by 25% and increased the yield of quality control rescreening 5.1 times (P < 0.0001). These data provide evidence that conventional screening and quality control rescreening of cervical smears fail to identify a substantial number of abnormalities. A significant improvement in performance of screening of cervical smears could be achieved with the use of the instrument described in this report.

Ameloblastoma. Cytologic findings and literature review.

OBJECTIVE: To define and elaborate the cytomorphologic features of primary and metastatic ameloblastoma (ABL) on fine needle aspiration (FNA) and to discuss the differential diagnosis with closely related entities and review the cytologic literature on the subject. STUDY DESIGN: A retrospective study consisting of five cases of ameloblastomas, primary in the mandible (n = 3) and metastases (n = 2), diagnosed by FNA cytology with appropriate cytohistologic correlation, was done. Smears were stained with the Diff-Quik and Papanicolaou methods. Hematoxylin and eosin-stained sections of paraffin block as well as sections from the surgically resected specimens were also reviewed. RESULTS: The smears were hypercellular and occasionally showed tissue fragments of basaloid cells with peripheral palisading. A distinct, two-cell population was seen, consisting of small, hyperchromatic, basaloid-type cells and scattered larger cells with more open chromatin. Occasional fragments of mesenchymal cells with more elongated nuclei and ample, clear cytoplasm were also noted. Malignant cases that metastasized showed prominent cytologic pleomorphism, cellular crowding with molding and a high mitotic/karyorrhectic index. CONCLUSION: In the right clinical setting and with proper radiologic evidence, the cytologic features of primary and metastatic ameloblastoma are unique. Diagnostic problems may arise when these lesions are pleomorphic and frankly malignant, especially at metastatic sites, such as the lung. FNA, therefore, is a valuable diagnostic tool in the initial diagnosis and follow-up of patients with a history of ameloblastoma.

Computerized scanning devices for Pap smear screening: current status and critical review.

Automation of the Pap smear has taken almost half of a century. Two systems have recently received FDA approval for routine use as quality control (rescreening) devices. Technical triumphs are overshadowed by current conflicts among cytopathology professionals, clinicians, patients, and device manufacturers. The historic perspective of this potentially volatile situation provides the backdrop for possible solutions based on the scientific validity of this evolving technology.

Differential diagnosis of Hürthle cell neoplasms on fine needle aspirates. Can we do any better with morphometry?

OBJECTIVE: To determine the value of computerized interactive morphometry in the preoperative prediction of malignancy in fine needle aspirates of Hürthle cell neoplasms. STUDY DESIGN: Alcohol-fixed, Papanicolaou-stained fine needle aspiration smears of histologically proven Hürthle cell adenomas (HCA) (n = 10) and Hürthle cell carcinomas (HCC) (n = 9) were studied by interactive computerized morphometry. The measured features included the areas, perimeters and shape factors of individual cells, nuclei and nucleoli; the nucleocytoplasmic and nucleolonuclear ratios; and the eccentricities of nuclei and nucleoli. RESULTS: Only nucleolar features showed statistically significant differences between HCA and HCC. These features were the nucleolar area and its standard deviation, the nucleolar form factor and circularity, and the nucleolonuclear ratio. The most effective, albeit imperfect, discrimination was achieved by the nucleolar form factor. CONCLUSION: Nucleolar features, such as size, variation in size and roundness, may be more effective than cellular or nuclear features in differentiating between HCA and HCC in fine needle aspiration smears.

Polymerase chain reaction-based K-ras mutation detection of pancreatic adenocarcinoma in routine cytology smears.

The cytologic diagnosis of pancreatic carcinoma is notoriously difficult, particularly in distinguishing benign atypia from well-differentiated adenocarcinoma. Mutation of codon 12 in the K-ras oncogene is frequently found with pancreatic cancers. Detection by polymerase chain reaction (PCR) followed by restriction endonuclease digestion can provide a powerful tool to improve and confirm diagnosis. The authors examined the utility of PCR-based detection in the diagnosis of pancreatic carcinoma using routinely obtained cytology smears that could be collected at most hospitals. Pancreatic cytology smears were collected retrospectively from 60 patients. DNA was extracted from the slides and amplified by PCR using mismatched primers that generated a Bst-N1 recognition site with the wild type codon 12 but not with the mutant allele. Results were compared with clinical follow-up. K-ras codon 12 mutations were observed in 44 of 46 (95.7%) cases of pancreatic cancer, but not in 12 benign cases nor in 2 cases of islet cell tumor. The amplification and digestion steps proved robust and sensitive, capable of detecting mutant K-ras alleles from cytology smears that contained only small foci of suspicious cells. Our results indicate that K-ras mutation analysis can be done reliably within 1 to 2 days from routine cytology slides without special handling, increasing the sensitivity of diagnosis in ambiguous cases while maintaining cost-effective and relatively noninvasive sampling strategy.