Case 73
Presentation
A 38-year-old man presents with multiple firm, purple-reddish-brown nodules and plaques on the lower extremities. The patient had been diagnosed with human immunodeficiency virus (HIV) 5 months before and had a history of hepatitis B infection. The patient has been treated for 4 months with highly active antiretroviral therapy (HAART), which has not improved his current disease.
▪ Clinical Photograph
 Figure 73.1 |
Physical Examination Report
Kaposi sarcoma (KS) on the medial aspect of the foot before chemotherapy: purple-reddish-brown nodules and plaques.
Differential Diagnosis
The differential diagnosis of reddish nodules on the extremities in adults includes lymphoma, KS, bacillary angiomatosis, cat-scratch disease, hemangioma, and angiosarcoma, as well as basal cell cancer and amelanotic melanoma.
Discussion
KS is a multifocal, polyclonal, hyperplastic neoplasm arising from lymphatic endothelial cells. KS is the most common tumor occurring in HIV-positive patients. Human herpes virus 8 (HHV-8) or KS-associated herpes virus (KSHV) together with cytokineinduced endothelial cell growth and some state of immunocompromise represent important conditions for its development. HHV8 DNA sequences have been shown to be associated with all different forms of KS, including the HIV-positive and HIV-negative forms.
In the United States, the risk for KS in patients with acquired immunodeficiency syndrome (AIDS)
was estimated to be more than 20,000 times that of the general population and 300 times that of other immunosuppressed patients. KS has been reported among all risk groups for HIV infection and in both sexes.
was estimated to be more than 20,000 times that of the general population and 300 times that of other immunosuppressed patients. KS has been reported among all risk groups for HIV infection and in both sexes.
AIDS-KS commonly presents multifocally and symmetrically. Lesions may begin as macules, frequently evolving to papules and tumors. Before the HAART era, oral KS lesions represented the first clinical manifestation in about one quarter of AIDS patients. In the HAART era, the incidence of KS in HIV-infected patients has decreased in the western world. In the United States, the AIDS-KS incidence has declined from 4.8 cases/100 persons/year in 1990 to 1.5 cases/100 persons/year in 1997. Once the diagnosis of KS is clinically suspected, it is confirmed by biopsy and histological examination.
Recommendation
Biopsy of thigh and laboratory tests.
Case Continued
The results of routine laboratory studies were within normal limits, including CD4+ and CD8+ lymphocyte counts and the CD4/CD8 ratio. HIV-RNA quantification revealed <50 copies/mL. HHV-8 was positive in the KS biopsy as assessed by polymerase chain reaction (PCR). The patient had IgG antibodies against HHV8, cytomegalovirus, and Epstein-Barr virus. He also had antibodies against the hepatitis B surface and core proteins (HBc-Ag and HBs-Ag).
▪ Histopathology Slide
 Figure 73.2 |
Histopathology Report
A specimen of the excised nodule reveals spindlelike tumor cells and numerous vascular spaces with extravasated erythrocytes. Spindle cells are dispersed throughout dermal collagen bundles forming irregular proliferations.
