Iraqi Board Pathology key terms

Programmed, energy-dependent cell death in which caspases dismantle the cell into membrane-bound bodies that are cleared without inflammation, occurring in development, hormone withdrawal, and immune-mediated killing.

Cell death pattern in which proteins denature and cytoplasm becomes eosinophilic and glassy while tissue architecture is preserved for days, typical of ischemic infarction in heart, kidney, and spleen.

Necrosis in which dead tissue is digested into a liquid viscous mass by released lysosomal enzymes, characteristically seen in brain infarction and in abscesses rich in neutrophils.

Combined coagulative and liquefactive necrosis producing a friable cheese-like material with amorphous granular debris and a granulomatous rim, classically found in tuberculosis and some fungal infections.

Additional tissue damage occurring when blood flow is restored to ischemic tissue, driven by reactive oxygen species, calcium overload, complement activation, and neutrophil influx, worsening infarct size.

Compact aggregate of activated macrophages with epithelioid morphology, often encircled by lymphocytes and fibrosis, formed to contain persistent intracellular organisms or foreign material.

Multinucleated macrophage-derived cell whose nuclei are arranged in a peripheral horseshoe or crescent pattern, commonly seen at the center of tuberculosis granulomas.

Multinucleated cell formed by fusion of macrophages at the surface of indigestible material such as suture, talc, or hair, with nuclei scattered irregularly rather than in a horseshoe arrangement.

Reversible replacement of one mature differentiated cell type by another that is better adapted to stress, such as squamous metaplasia of bronchial or cervical columnar epithelium; may predispose to dysplasia.

Disordered, non-neoplastic proliferation in which cells show pleomorphism, hyperchromasia, increased mitoses, and loss of normal maturation and architectural orientation; graded as low or high.

Severe dysplasia affecting the full thickness of an epithelium with intact basement membrane and no stromal invasion, carrying high risk of progression to invasive carcinoma.

Autonomous, heritable, excessive cellular proliferation that persists after removal of the initiating stimulus, resulting from accumulated genetic alterations and divided into benign and malignant forms.

Spread of malignant cells from a primary tumor to a discontinuous secondary site through lymphatics, blood vessels, body cavities, or transplantation, and the single most reliable feature of malignancy.

Microscopic assessment of a cancer's differentiation and proliferative activity, usually reported as grade 1 to 3, indicating biologic aggressiveness independently of anatomic extent.

Anatomic extent of a cancer at diagnosis, recorded by size, nodal involvement, and distant spread under the TNM system; the strongest predictor of prognosis and guide to therapy.

First draining lymph node from a tumor, identified by dye or radiotracer, whose histologic status predicts involvement of the remaining regional nodal basin and guides staging.

Rapid intraoperative tissue preparation in which unfixed tissue is frozen, cut, and stained within minutes, used for immediate diagnosis, margin assessment, and confirmation of lesional tissue.

Distortions caused by freezing and cutting unfixed tissue, including nuclear ice-crystal clearing, chatter, and folded or fragmented sections, which can mimic atypia and must be interpreted cautiously.

Immersion of tissue in buffered formaldehyde, which cross-links proteins and preserves morphology; neutral buffered formalin at about 10 percent is standard, with delayed fixation degrading antigens and DNA.

Brown-black acid hematin deposit appearing in blood-rich or poorly fixed tissue exposed to acidic formalin, distinguished from hemosiderin and melanin by its birefringence and removal by alcoholic picric acid.

Pretreatment of formalin-fixed tissue by heat or proteolytic enzymes to unmask epitopes cross-linked during fixation, restoring immunohistochemical staining for many nuclear and membranous markers.

Technique using labeled antibodies to detect specific antigens in tissue sections, employing avidin-biotin or polymer detection with chromogen, and requiring appropriate positive and negative controls.

Cell or tissue element within the patient's own slide that is expected to express the target antigen, confirming that staining reagents and retrieval worked before a negative result is accepted.

Intermediate filament protein of epithelial cells detected by broad-spectrum antibodies such as AE1/AE3, used to confirm epithelial origin and to identify metastatic carcinoma in lymph nodes.

Intermediate filament of mesenchymal cells and a sensitive marker of sarcomas, melanoma, and many neoplasms; coexpression with cytokeratin occurs in renal cell carcinoma and some others.

Intermediate filament protein of skeletal, cardiac, and smooth muscle, used to confirm muscle differentiation in rhabdomyosarcoma, leiomyosarcoma, and related tumors.

Standardized reporting framework for cervical cytology that states specimen adequacy and a diagnostic category, from negative for intraepithelial lesion through malignancy, with defined management implications.

High-grade squamous intraepithelial lesion on cytology, reflecting moderate to severe dysplasia or carcinoma in situ, with small cells showing high nuclear-to-cytoplasmic ratio and irregular nuclear membranes.

Atypical squamous cells of undetermined significance, the most common equivocal cervical cytology category, requiring HPV triage or repeat testing rather than immediate colposcopy in most patients.

Squamous cell with a wrinkled, hyperchromatic nucleus surrounded by a clear perinuclear halo and dense peripheral cytoplasm, the cytopathic hallmark of productive human papillomavirus infection.

Cervical sampling method in which cells are collected into fixative fluid, allowing thin-layer slide preparation, reduced obscuring blood and mucus, and ancillary HPV or p16 testing from the same vial.

Preparation in which centrifuged cytologic material is embedded in paraffin to yield histologic sections, permitting architectural assessment and immunohistochemical or special stains on fluid and aspirate specimens.

Sampling of a mass with a thin needle and suction or capillary action to obtain cells for smears and cell blocks, valued for speed and low morbidity but limited by sampling error.

Microcytic hypochromic anemia from depleted iron stores, showing low serum ferritin, low serum iron, raised total iron-binding capacity, and increased red cell distribution width; marrow shows absent iron.

Percentage or absolute number of newly released immature erythrocytes, reflecting marrow erythropoietic response; corrected or absolute values help classify anemia as hypoproliferative or hyperproliferative.

Core biopsy of marrow, usually from posterior iliac crest, preserving architecture for assessing cellularity, fibrosis, granulomas, and infiltration by lymphoma, carcinoma, or leukemia.

Laser-based technique measuring surface and intracellular antigens on suspended cells, essential for immunophenotyping leukemia and lymphoma and for detecting clonality and minimal residual disease.

Structured root-cause analysis of an unexpected death, serious injury, or mislabeled specimen, aiming to identify system failures and implement corrective actions rather than assign individual blame.

Program in which an outside body sends unknown samples or slides to a laboratory and compares results with peer laboratories, providing objective evidence of analytical and interpretive performance.