ABPATH Cheat Sheet 2026

The 30 highest-yield ABPATH facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. In liquid-based cytology, which advantage is most notable compared with conventional smears? → Reduced obscuring blood and inflammation with even cell distribution
2. A boggy, dilated heart with a mixed inflammatory infiltrate and myocyte necrosis on biopsy most suggests which diagnosis? → Lymphocytic myocarditis
3. Elevated conjugated (direct) bilirubin with elevated alkaline phosphatase most suggests which process? → Cholestasis/biliary obstruction
4. Which molecular finding defines a favorable-risk category in acute myeloid leukemia when NPM1 is mutated? → NPM1 mutation without FLT3-ITD (or low allelic ratio)
5. Which analyte requires collection on ice and rapid processing to avoid falsely low results? → Ammonia
6. Amyloid deposits appear apple-green birefringent under polarized light when stained with? → Congo red
7. Which immunostain confirms neuroendocrine differentiation in a suspected small cell carcinoma cytology specimen? → Synaptophysin
8. Apoptosis differs from necrosis primarily in that apoptosis: → Is energy-dependent and does not incite inflammation
9. Which of the following is a key histopathologic feature of Alzheimer's disease? → Neurofibrillary tangles
10. Which finding indicates high-grade dysplasia rather than invasive carcinoma in the colon? → Cells confined above the basement membrane
11. Which infectious agent is classically associated with dilated cardiomyopathy in South America? → Trypanosoma cruzi
12. A keloid represents which abnormality of wound healing? → Excessive collagen deposition beyond the wound margins
13. A patient with high PTH, low calcium, and high phosphate most likely has which condition? → Chronic kidney disease (secondary hyperparathyroidism)
14. Which of the following is the hallmark feature of hepatic cirrhosis on histopathological examination? → Portal fibrosis
15. Which enzyme is most useful for distinguishing hepatocellular from cholestatic liver injury when elevated predominantly? → ALT (hepatocellular) versus ALP (cholestatic)
16. Sterile, small vegetations on the lines of valve closure in a debilitated cancer patient are termed: → Nonbacterial thrombotic (marantic) endocarditis
17. Which stain is BEST used to highlight amyloid plaques in Alzheimer disease on formalin-fixed paraffin-embedded brain sections? → Congo red
18. Method validation for a new FDA-cleared assay used unmodified requires the lab to establish: → Verification of accuracy, precision, reportable range, and reference intervals
19. Which feature is used to distinguish invasive carcinoma from carcinoma in situ? → Breach of the basement membrane
20. Cyclin D1 overexpression from t(11;14) is diagnostic of which lymphoma? → Mantle cell lymphoma
21. Which organism produces a green pigment (pyocyanin) and a grape-like odor in culture? → Pseudomonas aeruginosa
22. Which bacterium causes whooping cough and is cultured on Bordet-Gengou or Regan-Lowe media? → Bordetella pertussis
23. A weak D phenotype is best explained by which molecular mechanism? → Reduced quantity of complete D antigen on the red cell
24. A delayed hemolytic transfusion reaction most often results from an anamnestic response to which antibody type? → Kidd (anti-Jka) antibodies
25. Which value indicates the specimen was contaminated with intravenous fluid containing dextrose? → Extremely high glucose with low potassium and sodium
26. The gel column agglutination method detects antigen-antibody reactions based on: → Trapping of agglutinated cells in a dextran gel matrix
27. Which histologic pattern of hepatocellular carcinoma is associated with the BEST prognosis? → Fibrolamellar carcinoma
28. Whipple disease is caused by which organism and is confirmed by which stain? → Tropheryma whipplei; PAS stain
29. Which accreditation body offers the deemed-status inspection program most commonly used by U.S. pathology laboratories? → College of American Pathologists (CAP)
30. What is the characteristic histologic feature of Crohn’s disease? → Granulomas