Under local anesthesia one of the 0.5 cm nodules from the left buccal mucosa was biopsied and sent for histologic evaluation.

Incisional Biopsy

Histologic examination of the H & E section revealed a thick surface epithelium with mild and broad papillary configuration supported by connective tissue. The surface epithelium was covered by a thin layer of parakeratin and the spinous layer was thick in most parts (Figure 3). Multiple mitosoid cells were identified within the middle and deep spinous layer (Figure 4). Also present were epithelial cells with pyknotic nuclei and empty-looking cytoplasm consistent with koilocytes.

Figure 3 Low power (x100) H & E histology shows oral mucosa covered by keratinized stratified squamous epithelium with mitosoid cells, koilocytes and a thick spinous layer. The underlying connective tissue is loose and vascula


Figure 4 High power (x200) higher power H & E histology taking a closer look at the multiple mitosoid cells within the mid to high spinous layer.