This paper is the last one in the series of publications on the investigation of the capability of Optical Coherence Tomography (OCT) in diagnostic of state of oral cavity mucosa. Part II demonstrates the diversity of optical images, different forms specific to leukoplakia, lichen planus and squamous cell carcinoma on the basis of the investigation of 56 pathologic lesions of 43 patients with precancer and cancer of oral cavity. The OCT sensitivity in malignancy detection in oral cavity is high - 83%, specificity is 98%, and accuracy is 81%. The kappa coefficient of interobserver agreement is 0.76.