Exfoliative cytology of primary poorly differentiated (small-cell) neuroendocrine carcinoma of the uterine cervix in ThinPrep material: a case report

Cytomorphological features of cervical small cell neuroendocrine carcinoma in SurePath™ liquid-based cervical samples

Small cell neuroendocrine carcinoma (SCNEC) of the cervix is a rare, highly aggressive tumour with poor prognosis and high propensity for distant metastases. The cytological features of SCNEC have rarely been described in cervical samples, and to the best of our knowledge, there are no previous reports using SurePath™ liquid-based cytology. In the present report we present the cytomorphological features of histopathologically confirmed cases of cervical SCNEC in SurePath preparations. On cytological examination, all three cases demonstrated variable numbers of tumour cells, ranging from a few dispersed cells and tiny micro-biopsies to large aggregates of small tumour cells with a high nucleus-to-cytoplasmic ratio, stippled chromatin, inconspicuous nucleoli, and scant cytoplasm. Immunocytochemistry for CD56 on the cervical preparation confirmed the diagnosis in one case. The presence of small tumour cells with characteristic stippled/salt-and-pepper type nuclear chromatin were the most consistent cytological features in these cases. Knowledge of these characteristic cytological features can help in suggesting a diagnosis of SCNEC in cervical samples which can then be confirmed by immunocytochemistry.

Capture of cervical exfoliative cells on a glass slide coated by 3-glycidyloxypropyl trimethoxysilane and poly-L-lysine

A new modification method for glass slides was developed and applied to make ThinPrep Pap smears, in order to increase the adhesion ability of cervical exfoliative cells. 3-glycidyloxypropyl trimethoxysilane (GOPS) was coated on the glass slides firstly on the slides, then poly-L-lysine (PLL) was covalently modified onto the above epoxy-terminated slides to form GOPS-PLL double decorated slides. The modified slides were characterized using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The cell adhesion ability effect was tested and compared with traditional PLL coated slides by fixing the cervical exfoliative cells on the double adorned slides. The control test was conducted by the bare glass slides unmodified. The cell morphology of cervical exfoliative cells adhered on different slides was observed under the microscope after Papanicolaou staining. The number of cervical exfoliative cells on the unmodified slides, PLL coated slides and GOPS-PLL coated slides was 1030±300, 3283±226 and 4119±280 (n=12), respectively. The data among the three different modification methods showed significant differences (one-way analysis of variance, ANOVA test, P<0.05). The cell capturing effect of the GOPS-PLL slide was the best among the three different modified slides. In addition, the GOPS-PLL slide could enhance the uniformity of the adhered cells and be widely applied to the ThinPrep system for cervical carcinoma screening to increase the accuracy rate of diagnosis.

Cytologic features of small-cell carcinoma on ThinPrep

The use of ThinPrep (TP) technology for fine-needle aspiration (FNA) cytology has become widely accepted. However, some literature suggests that small-cell carcinoma may present a diagnostic pitfall due to morphologic alterations. In this study, we retrospectively compared 14 FNA of small-cell carcinoma prepared using TP with corresponding conventional smears (CS). We also examined the TP appearance of 23 other small round-cell lesions in order to determine if differential diagnostic features were preserved. TP and CS were evaluated semiquantitatively for background, architecture, chromatin quality, nuclear molding, nuclear smearing, nucleolar prominence, amount of cytoplasm, nuclear size, and single-cell necrosis. The data were analyzed using the McNemar chi(2) test. TP slides of small-cell carcinoma showed a cleaner background than CS (P < 0.005). Although some degree of nuclear molding was preserved, it was decreased in amount (P < 0.025) and subtler in quality. Similarly, nuclear smearing was present but decreased in amount (P < 0.05), and less prominent qualitatively. The amount of discernible cytoplasm was greater on TP (P < 0.005). No significant differences were found for any of the other parameters studied. The presence of nuclear molding was the single most useful feature in differentiating small-cell carcinoma from other small round-cell tumors on TP. Small-cell carcinoma may be diagnosed with confidence by FNA using TP. However, pathologists should be aware of certain morphologic alterations in order to avoid diagnostic pitfalls.

A comparative study: conventional preparation and ThinPrep 2000 in respiratory cytology

In order to compare and contrast conventional preparation (CP) with ThinPrep 2000 (TP) in respiratory cytology, 207 samples were divided equally and processed by the two different preparation methods, generating three CP and one TP slide per sample. No lesion identified by CP was missed by TP and there were no significant differences between TP and CP in the diagnostic categories. However, two cases of squamous cell carcinoma were detected on TP which had been classified as unsatisfactory and moderate squamous dyskaryosis, respectively, on CP. ThinPrep was found to be superior to CP in many respects as it provided standardized preparations in a greater proportion of cases and problems such as cell overlapping and background debris were markedly reduced. In several instances the diagnostic accuracy in CP was compromised by smears that were either too thick, too thin, or too scanty. Cell preservation was also better on TP when compared with CP, facilitating more accurate diagnosis and significantly reducing the primary screening and reporting time, especially of sputum samples. A major advantage of TP methodology is the fact that it facilitates optimal use of skilled cytotechnologists and streamlines the workflow in the laboratory.

Thin-layer technology: tempered enthusiasm

With the introduction of new technologies we often see a pattern of development. As a useful technology moves into the public sector there is often an episode of wild enthusiasm and uncritical acceptance, followed by a time of progressive disillusionment. However, with time and experience, a proper place for the method becomes established. Thin-layer technology is certainly an improvement and solves many of our preanalytical problems; however, it introduces some difficulties of its own. The rounding up of cells in liquid fixation makes cells of high-grade lesions smaller than they would be on a conventional preparation. The abnormal cells are often separated. For both of these reasons they may be overlooked. Furthermore, benign glandular cells can take on an ominous appearance. These differences in conventional and thin-layer morphology are proving to be a fruitful area for publication. Thin-layer technology cannot be all things to all situations, and this is especially true in body fluid and fine-needle cytomorphology. In our experience, while occasionally helpful, the thin-layer technique should not be the primary method for diagnosis in nongynecologic specimens. Time and effort would be better spent on trying to educate select clinicians on how to obtain better samples than to totally convert to thin-layer methodologies. Regarding FNA, the patient is best served when the pathologist is directly involved with the initial sample acquisition. Reimbursement is available for immediate sample interpretation, so funding should be available for staffing if an institution has the interest. For the record, we believe that liquid fixation and thin-layer methodology should not be the primary method for FNA, unless circumstances are absolutely prohibitive. An important problem with thin-layer technology lies with its added cost. Thin-layer interposes another series of steps into cytologic sample preparation. There is additional labor, additional time, another machine in the laboratory, and the significant cost of the reagents. In a situation where the price of a cytologic test is already close to margin, costs of the vial, filter, and preservative throw the test into unprofitability. Price structures have to be changed. Some institutions are waiting until there is more competition in the market and costs decrease. Alternatively, a lot of effort has been expended in trying to get government and other groups to accept the additional costs of the new test for gynecologic examinations, and many payers seem to be falling in line to accept the methodology, secondary to clinician and patient demand. Basic questions about ancillary technologies and gynecologic samples remain to be answered. Cytology is big business. Every year a significant segment of the population has a Pap smear performed. Hardly any other laboratory test can claim the volume of activity of the cervical smear. Any business that can hook into that market stands to prosper. Since the Pap smear has some well-publicized problems, the door is open for technology to nibble away at a few percentage points of false negativity. We are far from the first to ask if we can afford the incremental improvements of thin-layer and other ancillary technologies. There is a conundrum. Government, insurance companies, and our administrators are calling for us to hold back cost increases in medical care. Alternatively, these new technologies, patient demand for the perfect test, increased regulatory oversight, and legal challenges are increasing the cost of doing business. We do not know how to respond to the often-voiced fear that these ancillary technologies increase the cost of cytology services beyond some patients' ability to pay. In this confusion, we do know that we should use the best test to get the most accurate answer for our patients. In selected scenarios this may mean that we will have to accept the cost and follow thin-layer technology.