Small and Thin Oral Squamous Cell Carcinomas may Exhibit Adverse Pathologic Prognostic Features.

We set out to record the frequency of recognised adverse pathologic features in early oral squamous cell carcinoma (OSCC) and correlate with neck disease, in particular in small and thin carcinomas, a group that might be assumed to behave less aggressively. We also examined the possibility of a biopsy site interfering with assessment of WPOI5 in small tumors. We reviewed all OSCCs ≤ 20 mm size and ≤ 10 mm depth reported at our institution over a 5-year period. Tumor maximum dimension, depth, perineural invasion (PNI), lymphovascular invasion (LVI), worst pattern of invasion (WPOI), and nodal status were recorded. Out of 95 cases, there were 44 (46.3%) small and 78 (82.1%) thin OSCCs. Depth and WPOI were significant factors in predicting nodal disease. There were 41 (43.2%) OSCC that were small and thin, of which 9.8% had PNI, none had LVI, and 61% had WPOI 4 or 5. Their rate of PNI and of nodal disease was similar to the other early OSCC. Assessment of WPOI5 at a biopsy site was only a problem in 2/38 cases. In early OSCC, depth and WPOI are important factors in predicting nodal disease. The very earliest OSCC (small and thin) have a similar rate of PNI and of nodal disease to other early OSCC, suggesting that while there may be a tendency to de-escalate treatment, these small tumours should be managed in the same way as for all early OSCC. In addition, the presence of scarring due to a biopsy in very small carcinomas rarely affects assessment of WPOI5.