DHA Anatomic Pathology exam questions

6 worked Anatomic Pathology practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Breast and Gynecologic Pathology

   An ovarian tumour with slit-like spaces, marked nuclear atypia and high mitotic activity is PAX8 positive and WT1 positive, with complete absence of p53 staining in all tumour cells. Which diagnosis is most likely?

   1. AHigh-grade serous carcinoma
   2. BEndometrioid carcinoma
   3. CClear cell carcinoma
   4. DLow-grade serous carcinoma
   Show answer and explanation

   Correct answer: A. High-grade serous carcinoma

   Complete absence of p53 staining is an aberrant (null) pattern indicating TP53 mutation, and with WT1 and PAX8 positivity this supports high-grade serous carcinoma. Clear cell and endometrioid carcinomas are usually WT1 negative, and low-grade serous carcinoma shows wild-type p53 staining.

   Reference: WHO Classification of Tumours: Female Genital Tumours, 5th ed.

2. Question 2 · Cytopathology

   A cervical Pap test shows superficial squamous cells with sharply defined perinuclear cavities, enlarged hyperchromatic nuclei and binucleation. How should this be reported?

   1. AHigh-grade squamous intraepithelial lesion
   2. BLow-grade squamous intraepithelial lesion
   3. CAtypical squamous cells, cannot exclude HSIL
   4. DNegative, reactive changes
   Show answer and explanation

   Correct answer: B. Low-grade squamous intraepithelial lesion

   Koilocytes in mature squamous cells with nuclear enlargement and hyperchromasia indicate HPV cytopathic effect and are reported as LSIL. HSIL involves smaller, immature cells with high nuclear to cytoplasmic ratios.

   Reference: The Bethesda System for Reporting Cervical Cytology, 3rd ed.

3. Question 3 · Cytopathology

   A cytotechnologist prepares direct smears from a lymph node FNA for Papanicolaou staining. How should these smears be handled immediately?

   1. AAir-dry completely before fixing
   2. BWet-fix at once in 95% ethanol
   3. CFix in 10% formalin for one hour
   4. DHeat-fix over a flame
   Show answer and explanation

   Correct answer: B. Wet-fix at once in 95% ethanol

   Papanicolaou staining requires immediate wet fixation, usually in 95% ethanol, to preserve nuclear detail. Air-dried smears are used for Romanowsky stains such as Diff-Quik, and air-drying artefact degrades Pap-stained nuclei.

   Reference: Koss' Diagnostic Cytology and Its Histopathologic Bases, 5th ed.

4. Question 4 · Gastrointestinal, Liver and Pancreatobiliary Pathology

   A 45-year-old woman has a multilocular cyst in the pancreatic tail that does not communicate with the main duct. Histology shows mucinous epithelium over a densely cellular stroma that is positive for oestrogen and progesterone receptors. What is the diagnosis?

   1. ASerous cystadenoma
   2. BIntraductal papillary mucinous neoplasm
   3. CMucinous cystic neoplasm
   4. DSolid pseudopapillary neoplasm
   Show answer and explanation

   Correct answer: C. Mucinous cystic neoplasm

   Ovarian-type stroma expressing ER and PR is required for a mucinous cystic neoplasm, which typically occurs in the body or tail in women and lacks duct communication. IPMN arises within and communicates with the duct system and lacks ovarian-type stroma.

   Reference: WHO Classification of Tumours: Digestive System Tumours, 5th ed.

5. Question 5 · Genitourinary and Renal Pathology

   A renal tumour consists of large polygonal cells with pale reticulated cytoplasm, prominent cell borders, wrinkled nuclei and perinuclear halos. Which immunoprofile best supports chromophobe renal cell carcinoma?

   1. ACK7 diffuse positive, CD117 positive
   2. BCK7 negative, CA9 diffuse membranous
   3. CCK7 negative, CD117 positive, patchy
   4. DAMACR diffuse positive, CK7 negative
   Show answer and explanation

   Correct answer: A. CK7 diffuse positive, CD117 positive

   Chromophobe RCC typically shows diffuse membranous CK7 and CD117 positivity. Oncocytoma is usually CD117 positive with CK7 negative or only scattered cells, clear cell RCC shows box-like CA9, and papillary RCC is AMACR positive.

   Reference: WHO Classification of Tumours: Urinary and Male Genital Tumours, 5th ed.

6. Question 6 · Head and Neck, Endocrine and Thoracic Pathology

   A pleural biopsy shows an epithelioid malignant tumour. Which combination of results most strongly favours epithelioid mesothelioma over metastatic lung adenocarcinoma?

   1. ANapsin A positive, D2-40 negative
   2. BClaudin-4 and TTF-1 positive, calretinin negative
   3. CCK5/6 negative, BerEP4 and MOC-31 positive
   4. DCalretinin and WT1 positive, claudin-4 negative
   Show answer and explanation

   Correct answer: D. Calretinin and WT1 positive, claudin-4 negative

   Mesothelioma is typically positive for calretinin, WT1, CK5/6 and D2-40 and negative for epithelial markers such as claudin-4, BerEP4, MOC-31 and TTF-1. The other combinations describe a carcinoma profile.

   Reference: Husain AN et al. Guidelines for Pathologic Diagnosis of Mesothelioma, Arch Pathol Lab Med 2018