Under local anesthesia an incisional biopsy was performed. Based on the diagnosis of the incisional biopsy, the patient underwent left partial glossectomy and left comprehensive neck dissection.

Incisional and Excisional Biopsy

Histologic examination reveals multiple pieces of soft tissue composed of surface epithelium exhibiting neoplastic changes invading the underlying fibrous connective tissue (Figure 2). The surface epithelium shows evidence of neoplastic changes; some confined to the surface while most others invading the connective tissue. The invasion is also in form of sheets as well as nests of neoplastic cells. The neoplastic cells show evidence of alteration in the nuclear/cytoplasmic ratio, loss of maturation, cells with large nuclei and prominent nucleoli, nuclear and cellular pleomorphism, individual cell keratinization and a few keratin pearls. Some of the neoplastic cells invaded the underlying skeletal muscle bundles (Figure 3). Immunohistochemistry for p16 was performed and was strongly positive (Figure 4).

Figure 2 Low power (x100) H & E histology demonstrating neoplastic epithelial islands, of variable shapes and sizes, invading the connective tissue.

Figure 3 Higher power (x200) H & E histology demonstrating neoplastic epithelial islands deep within the connective tissue and invading the underlying skeletal muscle bundles.

Figure 4 Higher power (x200) Immunohistochemistry staining with p16 demonstrating strongly positive staining of the neoplastic epithelial islands invading the connective tissue.