6 Vascular, Neural, and Muscle Tumors
• Purple-to-red nodule or papule, sessile or pedunculated; common on the gingiva (75% of cases [see Chapter 5]), upper lip, and buccal mucosa; there may be a history of bleeding (Fig. 6-1, A and B).
• Proliferation of endothelial cells and capillaries (often dilated)—sometimes in a lobular pattern, often with overlying ulceration—and acute and chronic inflammation are seen; mitoses are not uncommon (Figs. 6-2 and 6-3).
Varix (Venous Lake) and Venous Malformation (Venous Anomaly)
• Varix: dilated, tortuous, thin-walled vessels with a thin muscular coat; valve leaflets may be present (Figs. 6-7 and 6-8); thrombi in various stages of organization often noted with high cellularity or hyalinization; Masson tumor (intravascular papillary endothelial hyperplasia) sometimes seen (Figs. 6-9 to 6-11)
Soares AB, Altemani A, Furuse C, et al. Intravascular papillary endothelial hyperplasia: report of 2 cases and immunohistochemical study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008;106:708-711.
Caliber-Persistent Labial Artery
• There are four clinical presentations: (1) classic type involves the skin of lower legs in older men; (2) African endemic type is disseminated and involves viscera; (3) iatrogenic type is associated with immunosuppression (especially renal and lung transplantation); and (4) epidemic type is found in patients with HIV/AIDS and involves multiple sites, especially the skin and the mouth (this coexists with the endemic form in Africa).
• Dusky red or purple macule (early lesion), plaque, or mass (late lesion) is usually on the maxillary gingiva, palate, or tongue (Fig. 6-15); oral involvement is seen in only 2% to 5% of nonepidemic cases and in 60% to 70% of patients with HIV/AIDS.
This tumor is associated with activity of Kaposi sarcoma–associated herpesvirus (human herpesvirus-8); transmission may be through saliva rather than through blood or semen. Activation of viral lytic and latency genes leads to tumorigenesis, with initial tumor cells being polyclonal and more advanced tumors being monoclonal and immortalized.
• Cellular proliferation of spindle cells in small whorls or fascicles with abundant extravascular erythrocytes, hemosiderin and globular eosinophilic deposits, and some intracytoplasmic granules; mitotic activity may be noted (Figs. 6-16 and 6-17).
FIGURE 6-16 Kaposi sarcoma. A, Cellular proliferation of spindle cells, ectatic vessels, and abundant fresh hemorrhage. B, Spindle cells in short fascicles. C, Spindle cells show mild nuclear pleomorphism and mitotic activity, and erythrocytes are present between spindle cells.
• Patients newly diagnosed with HIV/AIDS require highly active antiretroviral therapy. Oral lesions are successfully treated with excision, laser ablation, intralesional vinblastine therapy, and radiation.
Lamovec J, Knuutila S. Kaposi’s sarcoma. In: Fletcher C, Unni K, Mertens F, editors. World Health Organization Classification of Tumours: Pathology and Genetics of Tumours of Soft Tissue and Bone. Lyon: IARC Press; 2002:170-172.