A Single Institutional Experience With the Paris System for Reporting Urinary Cytology: Correlation of Cytology and Histology in 194 Cases.

OBJECTIVES: The Paris System for Reporting Urinary Cytology (TPS) is designed to standardize the criteria and terminology used in urinary tract cytology reporting. The aim of this study was to evaluate the impact of implementing TPS and to analyze the correlation with follow-up biopsies in order to assess its reproducibility. METHODS: Urinary tract cytology specimens with follow-up biopsies over a 2-year period were reviewed and reclassified according to TPS criteria. Surgical follow-up diagnoses were correlated with the initial cytology diagnoses and TPS interpretations, and the results were compared. RESULTS: Applying TPS in comparison to our previous reporting system resulted in fewer cases in the atypia category (11.8% vs 24.2%) and higher specificity, accuracy, and predictive value. We observed acceptable interobserver agreement in diagnostic categories of this reporting system. CONCLUSIONS: TPS improves the overall performance of urinary tract cytology by standardizing the criteria and terminology.

Differentiating benign from malignant bone marrow B-cell lymphoid aggregates: a statistical analysis of distinguishing features.

CONTEXT: Lymphoid aggregates are seen in a minority of bone marrow biopsy specimens, and when present, their neoplastic nature is often apparent by morphologic evaluation. However, the distinction between benign and malignant aggregates can be a diagnostic challenge when there are multiple aggregates with no documented history of lymphoma. OBJECTIVE: To aid in the distinction between benign and malignant B-cell lymphoid aggregates. DESIGN: Previously, we described specific distribution patterns for B and T lymphocytes within bone marrow aggregates. To statistically analyze the significance of these patterns as well as previously reported criteria, we examined 128 bone marrow specimens with benign aggregates and 78 specimens with documented malignant B-cell aggregates and calculated specific odds ratios (ORs) and 95% confidence intervals (CIs) to aid in differentiating between benign and malignant B-cell aggregates. RESULTS: Aggregates with infiltrative edges (OR, 80.54; 95% CI, 31.76-204.21), a B-cell pattern (OR, 30.08; 95% CI, 13.28-68.10), paratrabecular location (OR, 10.17; 95% CI, 3.96-26.12), size greater than 600 µm (OR, 6.83: 95% CI, 3.61-12.93), or cytologic atypia correlated with malignancy. CONCLUSIONS: When taken collectively, the presence of more than 2 of these characteristic features was strongly predictive of malignancy.

Benign lymphoid aggregates in the bone marrow: distribution patterns of B and T lymphocytes.

Benign lymphoid aggregates are seen in only a minority of bone marrow specimens, but their distinction from non-Hodgkin lymphoma, particularly B-cell lymphomas, can represent a diagnostic challenge. Although criteria have been proposed to help distinguish between benign and malignant aggregates, a detailed description of the distribution patterns of B and T lymphocytes within benign lymphoid aggregates has not been investigated. One hundred thirty-seven cases of bone marrow specimens containing benign aggregates were studied with a panel of immunostains. A subset of these cases was also examined for immunoglobulin gene rearrangements by polymerase chain reaction. The aggregates were categorized based on size, location (paratrabecular or random), presence of infiltrating edges, and distribution of lymphoid cell populations. In addition, we examined 40 cases of bone marrow biopsies with documented malignant lymphoid aggregates for comparison purposes. We report that the distribution of B and T lymphocytes within lymphoid aggregates may serve as a useful criterion to aid in the separation between benign and malignant aggregates. When aggregates exhibit a predominance of T cells, consist of a central core of T cells surrounded by a rim of B cells, or have a mixed distribution of B and T cells, they are more likely to be benign. On the other hand, an increased likelihood of malignancy occurs when aggregates exhibit a predominance of B cells or consist of a central core of B cells surrounded by a rim of T cells (excluding germinal center formation), and assessing other features worrisome of malignancy (large aggregate size, presence of infiltrative edges, cellular atypia, and paratrabecular location, among others) is warranted.

Colorectal stents orient specimens and induce artifacts that mimic Crohn disease.

Colorectal malignancies may be stented to alleviate obstruction. The stent is a polarized and braided network of metallic wires. Pathology associated with colorectal stents is yet to be described. The authors reviewed 7 cases involving stented colorectal segments from patients lacking clinical suspicion of Crohn disease. In 4 cases, orientation of the specimens and stents matched the corresponding anatomic landmarks. In 3 cases, the specimens lacked helpful anatomic landmarks, and orientation was possible only after correlating with the intrinsic polarity of the stents. Stented areas showed artifacts resembling Crohn disease, including rounded cobblestones, pseudopolyps, and simple fissures, as well as unique artifacts including rhomboid cobblestones, complex fissures, oblique fissures with remarkably straight edges, and conical fragments of tissue that appeared to float. Crohn disease was misdiagnosed in 1 case in which the stent was removed intraoperatively and was never received. Colorectal stents help orient ambiguous specimens and induce patterned injury that can be confused with Crohn disease.