Neoplastic seeding of squamous cell carcinoma of the oropharynx.

Neoplastic seeding is a concept of mechanical disruption and spread of tumor into normal tissues. It is well-documented and accepted as an explanation for unusual patterns of tumor recurrence at multiple sites in the body. Neoplastic seeding is often invoked as an explanation for stromal recurrences following treatment of laryngeal carcinoma. However, it is impossible to discern whether these recurrences represent peritracheal lymph nodes, persistent or recurrent local disease, or neoplastic seeding of tumor. The purpose of this article is to report two cases of tracheostomy site recurrences after treatment of oropharyngeal squamous carcinoma, in which neoplastic seeding is the most plausible explanation of recurrence. The rarity of this phenomenon appears strikingly small despite significant experimental evidence supporting the possibility of its occurrence. Although specific recommendations for prevention cannot be made, it appears prudent to avoid re-use of instruments that come into direct contact with squamous cell carcinoma tumor surface.