Perineural invasion is commonly associated with which prognostic implication?

• A. Perineural invasion indicates better prognosis.
• B. Perineural invasion is irrelevant to prognosis.
• C. Perineural invasion is associated with higher recurrence and worse prognosis.
• D. Perineural invasion is a marker of infection only.

Answer: (C)

Perineural invasion shows cancer cells tracking along or around nerve fibers, a sign of aggressive tumor behavior. When tumor uses the perineural space as a route of spread, it can infiltrate beyond what is visible or resected, leading to higher chances of local recurrence and poorer overall prognosis. This pattern reflects a biology that tends to invade along neural pathways and invade adjacent structures more readily, making complete surgical clearance harder and disease control more challenging. It is not an infection marker, nor does it indicate a favorable or irrelevant prognostic factor. In most cancers, presence of perineural invasion is an adverse sign associated with worse outcomes and higher recurrence risk.