ABPath Cytopathology key terms

A standardized framework for naming and interpreting cervical cytology results, covering specimen adequacy, general categorization, and epithelial cell abnormality terminology that guides clinical management.

Atypical squamous cells of undetermined significance: squamous changes suggestive of a lesion but quantitatively or qualitatively insufficient for a definitive interpretation, requiring HPV triage or repeat testing.

Atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion: equivocal findings in which a high-grade lesion is possible, generally prompting colposcopy rather than watchful waiting.

Low-grade squamous intraepithelial lesion: cytologic changes of HPV infection or mild dysplasia, including koilocytosis, typically corresponding to histologic CIN 1.

High-grade squamous intraepithelial lesion: cytologic features of moderate to severe dysplasia, with reduced cytoplasm, increased nuclear-to-cytoplasmic ratio, and hyperchromasia, corresponding to CIN 2 or worse.

A squamous cell showing a perinuclear halo with sharp borders, nuclear enlargement, and nuclear membrane irregularity, the classic cytologic marker of productive HPV infection.

Cervical intraepithelial neoplasia: histologic grading (1 to 3) of squamous dysplasia based on how much of the epithelial thickness shows maturation loss and atypia.

Performing a high-risk human papillomavirus test alongside cervical cytology, usually in women aged 30 and older, to improve sensitivity for detecting significant cervical disease.

A determination of whether a cervical sample contains enough well-visualized squamous cells and, when relevant, endocervical or transformation zone cells to permit reliable interpretation.

Collection of cells from the squamocolumnar junction region where most cervical neoplasia arises; its presence supports adequacy, and its absence may be noted in the report.

Columnar glandular cells obtained from the cervical canal; their presence in a sample provides evidence that the transformation zone was sampled.

A Bethesda category for glandular cells showing atypia beyond reactive change but not clearly neoplastic, often requiring further evaluation of the endometrium and endocervix.

A preinvasive glandular lesion of the cervix showing neoplastic columnar cells with nuclear crowding, hyperchromasia, and apoptosis, often detected cytologically as atypical glandular cells.

Cytologic sampling of the anal canal, analogous to cervical cytology, used to screen for squamous dysplasia in high-risk populations such as HIV-positive individuals.

A preparation method in which collected cells are suspended in preservative fluid, allowing thin-layer slides and residual material for ancillary HPV testing.

A minimally invasive sampling technique using a thin needle to obtain cells and fluid from a mass for cytologic diagnosis, often guided by palpation or imaging.

Immediate microscopic assessment of aspirated material during a procedure to confirm adequacy, guide additional passes, and triage specimens for ancillary testing.

A preparation in which aspirated material is processed into a paraffin-embedded pellet, producing histologic sections that permit architectural assessment and immunohistochemical staining.

Application of antibody-based stains to cytologic preparations to identify cell lineage or origin, commonly used on cell blocks or smears to classify aspirated tumors.

A stain that highlights overexpression of the p16 protein, serving as a surrogate marker for high-risk HPV infection in squamous and glandular cervical lesions.

The proportion of a cell occupied by its nucleus relative to cytoplasm; an increased ratio is a key criterion for recognizing malignancy and high-grade dysplasia.

Variation in nuclear size, shape, and chromatin pattern among cells in a sample, a hallmark of malignancy and of high-grade epithelial lesions.

Aspiration of thyroid nodules to triage them into benign, indeterminate, suspicious, or malignant categories using a standardized reporting system that guides surgery.

Proteinaceous material normally present in thyroid aspirates, appearing as dense or watery background material; abundant colloid with bland follicular cells supports a benign diagnosis.

Cytologic sampling of salivary gland masses, often used to distinguish benign neoplasms such as pleomorphic adenoma from malignant tumors before resection.

Aspiration of enlarged lymph nodes to evaluate for metastatic carcinoma, lymphoma, or infection; ancillary flow cytometry or immunocytochemistry often supplements morphology.

Examination of cerebrospinal fluid for malignant cells, particularly in suspected leptomeningeal spread of leukemia, lymphoma, or carcinoma, requiring prompt processing to preserve cell detail.

Evaluation of pleural effusions for malignant cells, such as adenocarcinoma or mesothelioma, often aided by cell block preparations and immunohistochemical stains.

Benign mesothelial cells that enlarge and cluster in response to effusion or inflammation, a common mimic of adenocarcinoma in serous fluid specimens.

The Clinical Laboratory Improvement Amendments: federal regulations setting quality standards for laboratory testing, including personnel qualifications, proficiency testing, and quality control requirements.

A required external program in which a laboratory tests unknown specimens and its results are compared with peer laboratories to verify ongoing analytic performance.

Internal laboratory procedures that monitor test performance and detect errors, such as daily instrument checks and review of staining or screening results, to ensure reliable output.

A broader planned program of activities that evaluates and improves the entire testing process, including preanalytic, analytic, and postanalytic steps, beyond routine quality control.

A mandated quality practice in which a proportion of previously screened negative cervical slides are re-examined, often by a different screener, to detect missed abnormalities.

The interval between specimen receipt and report issuance; a key performance metric in cytology laboratory management that affects clinical decision-making and patient care.

Predefined conditions, such as missing patient identifiers or improper fixative, under which a laboratory will not process a specimen, protecting patient safety and compliance.

A laboratory professional trained to screen and initially interpret cytologic slides under supervision; staffing ratios and workload limits are regulated quality concerns.

Magnified visual examination of the cervix, often with acetic acid, used to evaluate abnormal cytology and direct biopsy of suspicious areas.