Kaposi Sarcoma (KS)
Kaposi Sarcoma is a vascular malignancy associated with Human Herpesvirus-8 (HHV-8) infection. It is an AIDS-defining illness and occurs predominantly in immunocompromised individuals.
Clinical Variants
- Epidemic (AIDS-related): Aggressive, multifocal; involves skin, lymph nodes, and visceral organs (GI tract/lungs).
- Classic (Sporadic): Seen in older men of Mediterranean/Ashkenazi Jewish descent; indolent course, mostly lower extremities.
- Endemic (African): Can be aggressive, often affecting children/young adults.
- Iatrogenic (Transplant-related): Occurs in patients on chronic immunosuppressive therapy.
Histopathology & Features
| Feature | Description |
|---|---|
| Morphology | Violaceous, red/purple, or brown macules, papules, or nodules. |
| Microscopic | Proliferation of spindle-shaped cells, vascular slits, and extravasated red blood cells. |
High-Yield Exam Pearl:
- HHV-8 Association: Always link KS to HHV-8. This is distinct from other viral-associated malignancies like EBV (Burkitt lymphoma) or HPV (cervical cancer).
- Management: In HIV-associated KS, the most effective treatment is often optimizing Antiretroviral Therapy (ART) to restore immune function. Chemotherapy (e.g., liposomal doxorubicin) is reserved for advanced/visceral disease.