The authors analyzed the results of 650 lesions of the central nervous system submitted to intraoperative cytological diagnosis by the smear technique. Cytological and paraffin section diagnoses were compared. The following statistical values were obtained: accuracy of 97.3%, sensitivity of 97.9%, specificity of 95%, positive predictive value of 99.1%, and negative predictive value of 89.6%. The authors comment on their main pitfalls using this cytological diagnostic procedure.

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The impact of specimen adequacy on the diagnosis of cervical cytology is not fully understood. Virtually, the greatest impact of smear quality limitation factors is on the diagnosis of atypical squamous cells of undetermined significance (ASCUS) because this category is more susceptible to interpretation mistake due to its criteria subjectivity. This study aims to evaluate the impact of smear quality impairing factors on the diagnosis of ASCUS. The 1,507 cases of ASCUS studied were obtained from the Cervical Cancer Screening Program of Paraná (CCSPP). The cases were reviewed by expert cytopathologists and the results were correlated to the specimen adequacy. The results showed that the presence of obscuring blood impairs the correct diagnosis and leads the pathologist to overdiagnose negative smears as ASCUS. The presence of adequate endocervical sampling contributes to a higher rate of correct ASCUS diagnoses but did not influence the pathologist to over- or underestimate the cytological findings.

Epidemiological data from the Quality Assurance Unit (QAU) of the Cervical Cancer Screening Program of Paraná is discussed. Slides (65,753) reviewed by the QAU, from October 1997 to July 1999, were analyzed. Relations between agreement rate, diagnostic categories, and age groups were tested. The overall agreement rate was 97.04% (kappa +/- 95%, confidence interval = 0.888 +/- 0.003). Low-grade squamous intraepithelial lesion (LSIL) showed its peak prevalence in patients < or = 19 yr (8.3%). High-grade squamous intraepithelial lesion (HSIL) was more common in women between 40 and 49 yr (5.0%). Squamous-cell carcinoma (SCC) was almost exclusively seen in women > or = 40 yr. The lowest agreement rates were seen in adenocarcinoma (54.5%; kappa = 0.667) and LSIL cases (76.3%, kappa = 0.822), and in women < or = 19 yr (95.8%). It was concluded that constant monitoring to assess specific errors allows directed measures. The 10% rescreening model of quality assurance proved to be effective in a low resources setting with a positive overall financial impact.

The dysembrioplastic neuroepithelial tumor (DNT) is a benign and slow-growing temporal lobe cortical lesion that presents with clinically unresponsive partial and complex seizures, with onset before age 20 yr. DNT shows a multinodular architecture and the presence of mixed glioneural elements. The authors report on a case of DNT diagnosed by the intraoperative smear cytological technique. We describe the cytological characteristics of smear preparations of DNT, with emphasis on the differential diagnosis. The authors present a 5-yr-old male with partial seizures for the preceding 3 yr. The patient showed no other neurological deficits. Magnetic resonance identified a lesion in the cortical area of the right temporal lobe. The smear cytology showed small, round, oligodendroglial-like cells arranged in lobules, with microcystic spaces containing ganglion cells floating in a fine fibrillary background. Histology confirmed the diagnosis of DNT. This report shows that the smear preparation can be trustworthy for the intraoperative diagnosis of DNTs, helping to determine the appropriate neurosurgical procedure and thus avoiding extensive and unnecessary resections.