Oropharyngeal Kaposi sarcoma in related persons negative for human immunodeficiency virus

Objectives: Kaposi sarcoma (KS) is a vascular tumor that can affect the mucosa of the upper aerodigestive tract. Although KS is the most common malignancy in patients with acquired immunodeficiency syndrome, it is rare in immunocompetent persons. We describe an unusual presentation of KS in 2 related individuals and describe our attempts to determine whether oropharyngeal KS is associated with human herpesvirus 8 (HHV-8). Methods: All relevant clinical and surgical information, including information on tumor histopathologic and human immunodeficiency virus (HIV) serologic tests, was abstracted from the patient charts and electronic databases. HHV-8 immunohistochemistry was performed on paraffin-fixed specimens. Results: Both patient 1 and patient 2 (the nephew of patient 1) were referred for workup of a tonsillar mass that was pathologically confirmed to be KS. In each case, HIV serologic testing was negative, and a screening immunologic workup, including a quantitative natural killer cell count, a B- and T-lymphocyte count, and immunoglobulin analysis, also yielded findings that were within normal limits. Immunohistochemistry performed on 1 pathological specimen showed positive staining for the presence of HHV-8, the etiologic agent of KS. Conclusions: The presence of oropharyngeal KS in 2 related HIV-negative individuals supports a role for genetic factors in susceptibility to KS, a common exposure to an infectious agent such as HHV-8, or both. Whereas most KS cases in industrialized countries are associated with immunodeficiency, clinical and laboratory data do not suggest that either of the patients described in this report are immunodeficient. Their susceptibility to KS may be secondary to a subtle inherited defect in host resistance to HHV-8, or another unknown factor.