ASCP PA cheat sheet

Frozen section indications: intraoperative diagnosis of malignancy, margin status, lymph node metastasis, and identification of tissue (e.g., parathyroid vs. thyroid); it is not used for definitive grading or for lesions requiring permanent-section architecture.

Surgical margins: an "ink" margin is positive when tumor touches the inked surface; "close" margins are reported with distance in mm (commonly <2 mm for breast, <1 mm for many others) and are distinct from positive margins.

Breast carcinoma biomarkers: ER/PR reported as percentage of positive nuclei plus intensity; HER2 scored 0, 1+, 2+ (equivocal, reflex ISH), 3+ by ASCO/CAP; Ki-67 is a proliferation index.

Colorectal carcinoma staging requires 12 or more lymph nodes for adequate nodal assessment; tumor deposits, extramural venous invasion, and peritoneal involvement are reported separately from N stage.

Prostate cancer: Gleason score is the sum of the two most prevalent patterns (primary + secondary); Grade Group 1 = Gleason 6, Group 2 = 3+4=7, Group 3 = 4+3=7, Group 4 = 8, Group 5 = 9-10.

Autopsy types: a complete autopsy examines all cavities and organs; a partial/limited autopsy is restricted by consent; a medicolegal (forensic) autopsy is performed under legal authority for manner-of-death determination.

Autopsy cause of death vs. manner of death: cause is the disease or injury producing death; manner is natural, accident, homicide, suicide, or undetermined.

Postmortem changes: livor mortis (dependent pooling) begins within hours, rigor mortis develops in small muscles first and resolves over ~24-48 hours, and algor mortis is postmortem cooling; these help estimate postmortem interval.

Frozen-section artifacts include ice crystal formation, chatter, and cautery artifact; touch preparations (cytology) can supplement frozen sections for cellular detail.

Formalin: 10% neutral buffered formalin is ~4% formaldehyde; recommended volume ratio is at least 10:1 formalin-to-tissue; neutral pH (~7.0-7.4) prevents formalin pigment (acid hematin).

Chemical safety: formaldehyde is a known human carcinogen with occupational exposure limits; glutaraldehyde, xylene, and toluene require fume hood use and appropriate PPE; OSHA Hazard Communication requires SDS access.

Universal precautions/standard precautions treat all blood and body fluids as potentially infectious; sharps must be discarded in puncture-resistant containers and never recapped by hand.

Quality control vs. quality assurance: QC is the testing of reagents/controls within a run; QA is the broader program (proficiency testing, audits, corrective actions) ensuring the overall system meets standards.

Proficiency testing (PT) performance: successful participation is required for accredited laboratories; unsuccessful PT results trigger investigation and corrective action under CLIA/CAP requirements.

Lean/Six Sigma concepts: a defect is any result outside specification; Six Sigma targets ~3.4 defects per million opportunities; root cause analysis (RCA) is used for sentinel events.

Turnaround time (TAT) is measured from specimen receipt (or order) to result reporting; delay causes include accessioning backlog, fixation time, and decalcification.

Specimen identification: two patient identifiers plus specimen labeling at the point of collection; mislabeled or unlabeled specimens are rejected per policy to prevent wrong-patient errors.

Biosafety levels: BSL-2 is standard for clinical diagnostic work with human specimens; BSL-3 is required for agents such as Mycobacterium tuberculosis culture and certain高风险 respiratory pathogens.