Cancer Cytopathology

The American Cancer Society recently revised the methods it will use to develop cancer screening guidelines. This commentary provides a summary of those new methods, and commentary on the roles of laboratory-based specialists and cytologists in future screening guideline development.

The author comments on a meta-analysis in this issue regarding cyclin-dependent kinase inhibitor 2A (p16^INK4a) and the triage of women who have minimally abnormal Papanicolaou tests. The meta-analysis provides a framework for future research; however, the method is not currently ready for widespread clinical use.

In this meta-analysis, the performance of cyclin-dependent kinase inhibitor 2A (p16^INK4a) immunocytochemistry in the triage of women with atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion cytology is compared with Hybrid Capture 2 testing. The published literature indicates improved accuracy (similar sensitivity, higher specificity) with p16^INK4a testing compared with Hybrid Capture 2 testing in the triage of atypical squamous cells of undetermined significance and higher specificity but lower sensitivity in the triage of low-grade squamous intraepithelial lesions.

Clear cell adenocarcinoma of the lower urinary tract is a rare neoplasm with minimal description in the cytology literature. Three-dimensional clusters and sheets of vacuolated tumor cells with signet ring features should raise suspicion for this tumor, with a differential diagnosis including metastatic adenocarcinomas, nephrogenic adenomas, and benign glandular lesions involving the bladder and urinary tract such as mullerianosis.

An indeterminate cytological diagnosis is not uncommon for fine-needle aspiration and brushing cytology specimens obtained from the patients evaluated for pancreaticobiliary lesions. The results from the current study demonstrate the diagnostic value of K-ras mutation analysis in those patients with equivocal cytology diagnoses.

The findings of the current study indicate that when experienced operators perform endoscopic ultrasound-guided fine-needle aspiration of the pancreas, the on-site adequacy evaluation offers no benefit in reducing the nondiagnostic rate. The authors also found that rinsing the entire sample in liquid-based media and omitting direct smears tended to improve the diagnostic rate.

The clinical impact of false negative thyroid fine-needle aspiration (TFNA) is minimal in our high-volume cancer center. Cancers following false negative TFNA are of low grade, and outcomes are not adversely affected despite the delay in diagnosis. Adjusting criteria by lowering the threshold for an equivocal diagnosis to enhance the sensitivity of TFNA is therefore not justified.

Fine-needle aspiration cytopathology is limited as a diagnostic instrument for the initial diagnosis of malignant peripheral nerve sheath tumor (MPNST), but is exceedingly accurate and valuable in the recognition of metastatic and locally recurrent MPNST.

In this study, the utility of the new Bethesda classification system for thyroid cytology reporting and molecular testing is examined for the first time in a pediatric population. The data reveal that thyroid fine-needle aspiration in this group is a sensitive and specific tool, with a higher rate of malignancy in the atypia of undetermined significance category. The molecular findings show a higher rate of molecular abnormalities than seen in adults, and a higher prevalence of RET/PTC rearrangements than BRAF mutations, in this young age group.

The clinical and cytomorphologic features of postradiation sarcoma (PRS) are presented. To the authors' knowledge, the current report is the first cytomorphologic study on a series of patients with PRS.