To learn if a new type of imaging device called the Active Biopsy Guidance System can help doctors to decide when and where to perform invasive biopsies of mouth lesions.

Primary objective:

-To evaluate and optimize the technical performance characteristics of an Active Biopsy Guidance System.

Secondary objective:

-To provide a preliminary estimate of the sensitivity and specificity of the Active Biopsy Guidance System with respect to histopathology. Optical imaging; optical projection of light onto tissue; optical contrast agent (proflavine).

Inclusion Criteria:

1. Adult subjects with clinically evident oral lesions such as leukoplakia or erythroplakia, oral potentially malignant disorders (OPMD) such as lichen planus and graft vs. host disease, pathologic diagnosis of dysplasia, squamous cell carcinoma, or a history of resected oral cancer, are eligible to participate. Patients with previous treatment including surgery, radiation, chemotherapy or other therapies are also eligible.
2. Ability to understand and willingness to sign a written Informed Consent Document (ICD).

Exclusion Criteria:

1. Known allergy to proflavine or acriflavine.
2. Age less than 18 years.
3. Pregnant or nursing females.
4. Adults unable to consent
5. Prisoners and other vulnerable populations