Dados do Trabalho

Título

NEGATIVE HHV-8 IMMUNOREACTIVITY IN LYMPHANGIOMA-LIKE KAPOSI'S SARCOMA

Apresentação do caso

Female patient, 66 years old, presenting asymptomatic erythematous-violaceous macules on the medial surface of the right and left feet, for about 20 years. Biopsy was performed and the histopathologic analysis revealed alterations compatible with lymphangioma and positive immunohistochemistry for CD31, CD34 and negative for human herpesvirus 8 (HHV-8). After 2 months, the patient returned with changes in the lesion, which became more exophytic and friable. A new histopathological biopsy was performed, which was compatible with the diagnosis of Kaposi's sarcoma lymphagioma simile. Immunohistochemistry was negative for HMB45, Melan A, and positive for Protein S-100, CD31, CD34, CD68, kl67 cell proliferation antigen and strongly immunoreactive for HHV-8.

Discussão

Kaposi's Sarcoma Lymphangioma-like is a malignant vascular neoplasm with findings of lymphatic and blood differentiation. It is a rare histological variant of Kaposi's sarcoma, corresponding to only 5% of these. The first cases were reported in 1957 and since then only 30 cases have been published. Histopathological changes consist of anastomosed networks of small, irregular and dilated channels in the dermis. These atypical channels are lined with flat endothelial cells. In contrast to typical Kaposi's sarcoma, there is no dense proliferation of spindle cells. Immunohistochemistry for HHV-8 positive has been a finding of great importance in the knowledge of the etiopathogenesis, but in occasional cases it can be negative.

Comentários finais

This case highlights that initial HHV-8 negative immunohistochemistry should not completely exclude the diagnosis of KS when the clinic is suggestive. In the present case, the second biopsy and immunohistochemistry were essential for the definitive diagnosis, but techniques such as the use of polymerase chain reaction (PCR) to search for HHV-8 transcripts can be diagnostic alternatives.

Palavras-chave

Sarcoma; Kaposi; Lymphangioma