ABSTRACT
A. ‘‘De Novo’’ Versus AIDS Lymphoma 1. Pathological Spectrum of Disease The de novo lymphomas, which may occur in human immunodeficiency virus (HIV)-noninfected individuals, are clearly distinct from those occurring in the setting of underlying HIV infection. Pathologically, acquired immunodeficiency syndrome (AIDS)-related lymphomas comprise a rather narrow spectrum of histological types, consisting almost exclusively of B-cell tumors, of high-grade or large cell type (1). These include diffuse large cell lymphoma, B-immunoblastic and small-noncleaved lymphomas, the latter of which may represent either Burkitt’s or Burkitt-like subtypes. All three of these pathological types appear equally distributed in patients with AIDS lymphoma (2), so that approximately two-thirds of AIDS lymphomas are of the high-grade, B-cell type. This pathological spectrum of disease is in sharp contrast with that expected in the usual setting, in which only approximately 10% of patients have a diagnosis of high-grade lymphomas (1). Recently, several additional pathological entities have been described in HIV-infected patients with lymphoma, including body-cavity-based
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lymphoma (BCBL; also termed primary effusion lymphomas), associated with coinfection by the newly discovered human herpes virus type 8 (HHV-8; 3-5); and anaplastic large cell lymphoma (6). Although primary effusion lymphoma appears more common in HIV-infected individuals, the entity has also been described without underlying HIV infection, and appears to be clinically similar in both settings (7). Likewise, anaplastic large cell lymphoma has also been welldescribed in de novo lymphoma, with similar clinical and pathological characteristics in both HIV-infected and noninfected individuals (8).
