A liquid concept--do classic preparations of body cavity fluid perform differently than ThinPrep cases? Observations from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology.

Context: Newer liquid-based preparations differ morphologically from classic preparations (smears, filters, and cytocentrifuged preparations). Is adenocarcinoma more readily detected in liquid-based preparations? We reviewed responses from 16,750 fluid challenges of adenocarcinoma distributed in 2005 in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology (CAP NGC).

Objective: To compare the performance of body cavity fluid liquid-based preparations with adenocarcinoma to that in classic preparations in the CAP NGC.

Fine-needle aspiration biopsy of lymphoproliferative disorders--interpretations based on morphologic criteria alone: results from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology.

Context: Diagnosis of lymphoproliferative disorders is one of the most challenging tasks faced by the cytologist. The initial cytomorphologic evaluation of lymphoproliferative lesions directs the choice of ancillary studies that ultimately lead to a diagnosis based on the World Health Organization classification system using a composite of clinical, morphologic, immunophenotypic, and molecular features.

Objective: To evaluate the ability of participating laboratories in the College of American Pathologists Interlaboratory Comparison Program in Non-Gynecologic Cytopathology to appropriately categorize lymphoproliferative lesions based solely on cytomorphologic criteria.

Leukemia/lymphoma in cerebrospinal fluid: distinguishing between cases that performed well and poorly in the College of American Pathologists Interlaboratory Comparison Program in Non-gynecologic Cytology.

Context: Although the cytologic features of leukemia/lymphoma in cerebrospinal fluid specimens are well known, the correlation of these features with the ability of cytologists to identify this tumor have not been well studied.

Objective: To identify the morphologic features of leukemia/lymphoma in cerebrospinal fluid that are associated with good performance and poor performance in an educational interlaboratory comparison program; and to identify the morphologic features associated with how well a slide performs with regard to its reference diagnosis.

Design: The performance of 147 cases of leukemia/lymphoma in the College of American Pathologists Interlaboratory Comparison Program in Non-gynecologic Cytology was analyzed.

Distinguishing carcinoid tumor of the mediastinum from thymoma: correlating cytologic features and performance in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology.

Context: The cytologic features of carcinoid tumor in mediastinal fine-needle aspiration are well described. Nevertheless, this tumor may be difficult to distinguish from thymoma in this site.

Objective: We sought to correlate the cytologic features of carcinoid tumor of the mediastinum in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology with the frequency of misclassification as thymoma.

Fine-needle aspiration of papillary thyroid carcinoma: distinguishing between cases that performed well and those that performed poorly in the College of American Pathologists Nongynecologic Cytology Program.

Context: Although the cytologic features of papillary thyroid carcinoma in fine-needle aspiration specimens are well known, the correlation of these features with the ability of cytologists to identify this tumor has not been well studied.

Objective: To compare the cytologic features of cases of papillary thyroid carcinoma that performed poorly with those of cases that performed well.

Design: The cytologic features of 13 cases of papillary thyroid carcinoma from the College of American Pathologists Nongynecologic Cytology Program that performed poorly were compared with those of 15 cases that performed well.

Hyperchromatic crowded groups in cervical cytology--differing appearances and interpretations in conventional and ThinPrep preparations: a study from the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology.

Context: The practice of gynecologic cytology requires that high-grade squamous intraepithelial lesion (HSIL) be precisely recognized. In this regard, hyperchromatic crowded groups are known to be difficult to classify in conventional gynecologic cytology, but whether this is true in ThinPrep specimens is uncertain.

Objective: To assess whether hyperchromatic crowded groups of cells in challenging HSIL cases are a problem in ThinPrep preparations, and whether these groups differ in appearance from those of conventional smears.

Interobserver agreement on microfollicles in thyroid fine-needle aspirates.

Context: Although microfollicles are a well-known feature of follicular neoplasms in fine-needle aspirates of the thyroid, the level of agreement about classifying groups as microfollicles is not known.

Objective: To determine what features are present in groups that are consistently classified as microfollicles.

Design: We showed 45 small groups of follicular cells each composed of fewer than 50 cells from fine-needle aspirates of the thyroid to 12 members of the College of American Pathologists Cytopathology Committee, who then classified the groups into microfollicles, macrofollicles, and indeterminate groups.

Cytologic features of adenocarcinoma, not otherwise specified, in conventional smears: comparison of cases that performed poorly with those that performed well in the College of American Pathologists Interlaboratory Comparison Program in cervicovaginal cytology.

Context: Characteristic cytologic features have been identified that distinguish cases that are consistently identified from those that are sometimes missed in the College of American Pathologists Gynecologic Cytology Program for a variety of different lesions and preparations.

Objectives: To compare the cytologic features of cases of adenocarcinoma, not otherwise specified (NOS), in conventional smears that perform poorly and well.

Design: The cytologic features of 21 conventional smear cases of adenocarcinoma, NOS, that performed poorly in the College of American Pathologists Interlaboratory Comparison Program were compared with 17 cases that performed extremely well.

Fine-needle aspirates of hepatocellular carcinoma that are misclassified as adenocarcinoma: correlating cytologic features and performance in the College of American Pathologists Nongynecologic Cytology Program.

Context: The cytologic features of hepatocellular carcinoma in fine-needle aspirates are well described. While some cases are easily distinguished from adenocarcinoma, poorly differentiated tumors can be difficult to differentiate. We reviewed the cytologic findings for 9 aspirates from cases of hepatocellular carcinoma that were frequently misclassified as adenocarcinoma and compared them with another 10 cases of hepatocellular carcinoma that were rarely misclassified.

Fine-needle aspirates of adenocarcinoma/metastatic carcinoma that resemble hepatocellular carcinoma: correlating cytologic features and performance in the College of American Pathologists Nongynecologic Cytology Program.

Context: The cytologic features of adenocarcinoma/ metastatic carcinoma in liver fine-needle aspirates are well described. We review the cytologic findings from 16 aspirates of adenocarcinoma/metastatic carcinoma that were frequently misclassified as hepatocellular carcinomas and compare them with 17 cases that were rarely misclassified.

Objective: To compare the cytologic features of adenocarcinoma/metastatic carcinoma in fine-needle aspiration specimens of the liver that were frequently misclassified as hepatocellular carcinoma with those of aspirates that were rarely misclassified.

Cytologic features of squamous cell carcinoma in conventional smears: comparison of cases that performed poorly with those that performed well in the College of American Pathologists Interlaboratory Comparison Program in cervicovaginal cytology.

Context: Characteristic cytologic features have been identified that distinguish cases that are always identified from those that are sometimes missed in the College of American Pathologists Gynecologic Cytology Program for a variety of different lesions and preparations.

Objective: To compare the cytologic features of cases of squamous cell carcinoma in conventional smears that perform poorly and well.

Design: The cytologic features of 8 conventional smear cases of squamous cell carcinoma that performed poorly in the College of American Pathologists Interlaboratory Comparison Program were compared with 17 cases that performed extremely well.

Cytologic features of high-grade squamous intraepithelial lesion in conventional slides: what is the difference between cases that perform well and those that perform poorly?

Context: Previous studies have suggested that cases of high-grade squamous intraepithelial lesion in conventional smears and in ThinPrep specimens that are frequently misinterpreted as normal have relatively few small and hypochromatic dysplastic cells.

Objective: To determine the cytologic differences between conventional Papanicolaou slides of high-grade squamous intraepithelial lesion that perform poorly and those that perform well.

Design: We compared the cytologic features of 22 cases of conventional smears with high-grade squamous intraepithelial lesion that performed poorly in the College of American Pathologists Interlaboratory Comparison Program in Gynecologic Cytology with 45 cases of conventional smears that performed extremely well.

Distinguishing small cell carcinoma from non-small cell carcinoma of the lung: correlating cytologic features and performance in the College of American Pathologists Non-Gynecologic Cytology Program.

Context: The cytologic features of small cell carcinoma of the lung are well described. Nevertheless, some small cell carcinomas may be difficult to reproducibly distinguish from non-small cell carcinomas, and this distinction carries significant clinical importance.

Objective: To correlate the cytologic features of individual cases of small cell carcinoma of the lung in fine-needle aspiration specimens from the College of American Pathologists Non-Gynecologic Peer Comparison Cytology Program with the frequency of misclassification as non- small cell carcinoma.

Distinguishing carcinoid tumor from small cell carcinoma of the lung: correlating cytologic features and performance in the College of American Pathologists Non-Gynecologic Cytology Program.

Context: The cytologic features of carcinoid tumor of the lung are well described. Nevertheless, some carcinoids may be difficult to distinguish from small cell carcinomas.

Objective: To correlate the cytologic features of individual cases of carcinoid tumor of the lung in fine-needle aspiration specimens in the College of American Pathologists Non-Gynecologic Cytology Program with the frequency of misclassification as small cell carcinoma.

Cytologic features of low-grade squamous intraepithelial lesion in thinprep papanicolaou test slides and conventional smears: comparison of cases that performed poorly with those that performed well in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology.

Context: Both conventional and ThinPrep Papanicolaou smears with high-grade squamous intraepithelial lesions that are frequently missed are known to have relatively few abnormal cells. Whether this is also true of cases of low-grade squamous intraepithelial lesion is not known.

Objective: To compare the cytologic features of cases of low-grade squamous intraepithelial lesion that perform poorly with the features of cases that perform well.