CTR Cancer Biology & Pathology 1 — Questions and Answers
Question 1: In ICD-O-3, what does a behavior code of '/3' indicate?
- Benign neoplasm
- Malignant, primary site (Correct answer)
- Malignant, metastatic or secondary site
- Uncertain malignant potential
Correct answer: Malignant, primary site
Behavior code '/3' in ICD-O-3 designates a malignant primary site tumor, distinguishing it from benign ('/0'), borderline ('/1'), and metastatic ('/6') designations.
Question 2: Which histologic type of lung cancer is most commonly diagnosed in non-smokers and women?
- Squamous cell carcinoma
- Small cell carcinoma
- Adenocarcinoma (Correct answer)
- Large cell undifferentiated carcinoma
Correct answer: Adenocarcinoma
Adenocarcinoma is the most frequent lung cancer subtype in non-smokers and women, often arising peripherally in the lung and associated with EGFR mutations.
Question 3: Carcinoma in situ (CIS) is best defined as:
- Malignant cells that have invaded through the basement membrane
- Malignant cells confined to the epithelium with no basement membrane invasion (Correct answer)
- A benign tumor with potential for malignant transformation
- Cancer that has spread to regional lymph nodes
Correct answer: Malignant cells confined to the epithelium with no basement membrane invasion
Carcinoma in situ consists of malignant epithelial cells that have not yet breached the basement membrane, making it non-invasive by definition.
Question 4: Tumor grade primarily describes which characteristic of a neoplasm?
- The anatomical extent of spread at diagnosis
- The degree of cellular differentiation relative to normal tissue (Correct answer)
- The size of the primary tumor in centimeters
- The number of positive lymph nodes identified
Correct answer: The degree of cellular differentiation relative to normal tissue
Tumor grade reflects how closely cancer cells resemble normal cells microscopically; low-grade tumors are well-differentiated and high-grade tumors are poorly differentiated.
Question 5: Adenocarcinoma is a malignancy arising from which tissue type?
- Stratified squamous epithelium
- Transitional (urothelial) epithelium
- Glandular epithelium (Correct answer)
- Mesothelial lining cells
Correct answer: Glandular epithelium
Adenocarcinoma (prefix 'adeno-') originates from glandular epithelial cells and is common in organs such as the colon, breast, lung, and prostate.
Question 6: Which laboratory technique uses antibodies to detect specific proteins expressed by tumor cells and is routinely reported on pathology reports?
- Flow cytometry
- Immunohistochemistry (IHC) (Correct answer)
- Fluorescence in situ hybridization (FISH)
- Polymerase chain reaction (PCR)
Correct answer: Immunohistochemistry (IHC)
Immunohistochemistry (IHC) applies labeled antibodies to tissue sections to visualize protein expression, commonly used to classify tumors and guide targeted therapy selection.
Question 7: A pathology report describes a tumor as 'poorly differentiated.' What does this indicate to the tumor registrar?
- The tumor cells closely resemble normal tissue and grow slowly
- The tumor cells bear little resemblance to normal tissue and tend to be aggressive (Correct answer)
- The tumor is benign and unlikely to metastasize
- The tumor is at an early stage with favorable prognosis
Correct answer: The tumor cells bear little resemblance to normal tissue and tend to be aggressive
Poorly differentiated (high-grade) tumors have cells that look very abnormal under the microscope, correlating with more aggressive behavior and typically worse prognosis.
CTR Cancer Biology & Pathology 1
In ICD-O-3, what does a behavior code of '/3' indicate?