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SUMMARY
There are four major subtypes of Kaposi sarcoma (KS): classic, endemic, HIV-associated, and iatrogenic. Clinical characteristics overlap, but certain features are more prominent in some variants than in others.
KS requires infection with human herpesvirus-8 (HHV-8), though this is not sufficient to cause the neoplasm. Most patients have some level of immune dysregulation.
Histologically, KS presents as a patch, plaque, or nodule characterized by spindle cell vascular proliferation with extravasated red blood cells, lymphocytic infiltrates, and hyaline globules.
Therapy selection is based on clinical subtype, disease progression, distribution, and severity.
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DON’T FORGET
Many entities can be confused with KS. A biopsy of the lesion and confirmation by histology is necessary for a diagnosis of KS.
Additional imaging and investigations (computed tomography, upper gastrointestinal endoscopy) are not warranted in the absence of reported symptoms.
Immunohistochemistry for latency-associated nuclear antigen (LANA-1) is the most specific test for HHV-8 and can confirm a diagnosis of KS.
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CLINICAL PEARLS
Cutaneous lesions are described as red-brown or violaceous patches, plaques, or nodules that can ulcerate or bleed.
Visceral involvement is rare in classic KS but is more frequently found in other subtypes. The oral mucosa, lymph nodes, lungs, and gastrointestinal system have been implicated in disseminated disease.
Localized disease is treated with locally ablative methods like cryotherapy, surgical excision, or injection of an immunomodulator.
Systemic or advanced disease requires chemotherapeutic agents. The gold-standard treatment is pegylated liposomal doxorubicin and paclitaxel.
AIDS-related KS benefits from antiretroviral therapy. Iatrogenic KS is managed with immune reconstitution.
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PATIENT EDUCATION POINTS
Patients should be taught to monitor the progression of mucocutaneous lesions and to report any new symptoms, such as edema, cough, hemoptysis, abdominal pain, or bowel movement changes.
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Kaposi sarcoma (KS) is an endothelial proliferative disorder that is strongly associated with human herpesvirus-8 (HHV-8) infection, also known as KS-associated herpesvirus (KSHV).1 It was first reported in 1872 by Moritz Kaposi who noted the appearance of “idiopathic multiple pigmented sarcoma of the skin” in five older adult European men.1
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Based on epidemiological features, four clinical variants of KS have been widely recognized2-4:
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Classic/sporadic KS is an indolent disease that occurs mostly in older adult men of Mediterranean or Jewish ancestry. It primarily affects the skin on the legs and feet and generally lacks visceral involvement.
African/endemic KS encompasses several subtypes, the most common of which is lymphadenopathic KS. Unique features include widespread lymph node involvement, lymphedema, and an aggressive disease course with visceral manifestations.
AIDS-associated/epidemic KS is the most common tumor arising in HIV-positive individuals. KS is considered to be an AIDS-defining illness and typically affects the head and neck, trunk, and mucosa. Its clinical course is rapidly progressive, though improvement may be seen with antiretroviral therapy.
Iatrogenic or transplantation-associated KS presents as cutaneous KS lesions. Visceral and mucosal lesions ...