Verrucous Carcinoma of the Anus
Differential Diagnosis
- Pseudoepitheliomatous hyperplasia
- Usual squamous cell carcinoma
- Condyloma acuminatum
- Podophylin effect vs usual squamous carcinoma
- Verrucous carcinoma is characterized by blunt, destructive downward growth
- This distinction is frequently not possible on histologic grounds alone
- Frequently requires clinical correlation
- Note that usual squamous carcinoma can develop in verrucous carcinoma
- Verrucous carcinoma with podophyllin effect should be distinguished from usual squamous cell carcinoma
- Podophyllin does not produce:
- Cytologic dysplasia
- Disturbance of maturation
- Dyskeratosis
- Early podophyllin effects (≤48 hours post application)
- Intra- and intercellular edema
- Necrotic keratinocytes in lower half of epithelium
- Numerous mitotic figures in lower half of epithelium
- Changes resolving by 72 hours
- Necrotic keratinocytes now in upper half of epithelium
- Fewer mitotic figures
- Changes entirely resolved by one week
Verrucous Carcinoma vs. Pseudoepitheliomatous Hyperplasia
| Verrucous Carcinoma of the Anus | Usual Squamous Carcinoma of the Anus |
| Only blunt pushing invasion | Jagged invasion |
| No more than mild dysplasia | Usually significant dysplasia |
| Mitotic figures confined to basal layer unless inflamed | Mitotic figures may be present at all levels |
| No vascular or perineural invasion | May have vascular or perineural invasion |
| Does not metastasize | May metastasize |
| Verrucous Carcinoma of the Anus | Condyloma Acuminatum |
| Usually large | Usually small |
| Blunt destructive downward growth | Superficial lesion, no destructive growth |
| May develop fistulas and sinuses | Does not produce fistulas or sinuses |
