SBA — Single Best Answer · Review
Question 380
Pathology → General
Classification
Question
SSBAQuestion Header
A tumour is being assessed histologically for malignant behaviour. Several abnormalities are identified, but one finding provides direct evidence of malignant local behaviour rather than merely cellular atypia. Which is the strongest finding?
Question Stem
Select the single best answer.
Options
A
Variation in nuclear size
B
Increased nuclear-to-cytoplasmic ratio
C
Local infiltration into surrounding tissue
D
Loss of cellular polarity
E
Increased mitotic activity
Explanation
Malignant tumours characteristically invade surrounding tissues and may metastasise. Pleomorphism, increased nuclear-to-cytoplasmic ratio, loss of polarity and increased or atypical mitotic activity support malignant morphology, but local infiltration demonstrates invasive malignant behaviour directly.
Option Validity
A) Nuclear pleomorphism supports atypia but does not by itself demonstrate local invasive behaviour.
B) An increased nuclear-to-cytoplasmic ratio is a cytological feature of malignancy but is not direct evidence of tissue invasion.
D) Loss of polarity is an important malignant cytological feature but does not itself prove infiltration of adjacent tissue.
E) Increased mitotic activity may occur in proliferating tissue and, although supportive in context, does not directly demonstrate local invasion.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 5: Pathology. General Pathology, pp.161–175.