Kaposi's Sarcoma

Types and Classification

There are several clinical forms of Kaposi's sarcoma, each with unique characteristics in terms of progression, prognosis, and cause. The main differences relate to the underlying causes, development speed, and the patient populations in which the tumor occurs:

• Classic Form – Typically occurs in elderly men of Mediterranean or Eastern European descent. It progresses slowly and primarily affects the skin of the lower limbs, manifesting as purple or brown spots and nodules. Involvement of internal organs is rare.

• Endemic (African) Form – Common in residents of Central and Eastern Africa. It can affect both adults and children, with skin and visceral manifestations. This form often progresses aggressively and is not always linked to HIV.

• Immunosuppressive Form – Develops in patients receiving immunosuppressive medications following organ transplantation. The weakened immune system enables HHV-8 to become active. In some cases, the tumor may regress if immunosuppressant dosage is reduced.

• Epidemic (HIV-associated) Form – The most common form during the HIV epidemic. It features multiple skin and mucosal lesions, rapid progression, and frequent involvement of internal organs.

Accurate classification is critical, as treatment strategies depend on the type of disease.

Causes and Risk Factors

The primary cause of Kaposi's sarcoma is infection with human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma-associated herpesvirus. However, infection alone is not sufficient—immune system dysfunction also plays a key role. 

Major risk factors include:

• Immunodeficiency – The most significant factor. Risk is especially high in HIV-positive patients with low CD4 counts. Patients who have undergone organ transplants and are on immunosuppressive therapy are also at risk.

• HHV-8 Infection – Without HHV-8 infection, Kaposi's sarcoma does not develop. Transmission can occur through blood, saliva, and sexual contact.

• Geographic Factors – HHV-8 is more prevalent in Central and Eastern Africa and among men of Mediterranean descent.

• Sex and Age – Men are more frequently affected, especially older individuals with the classic form.

• Other Chronic Diseases – Conditions such as hepatitis or tuberculosis, which further compromise immune function, can also increase risk.

Tumor development typically requires both viral infection and immune dysfunction—whether congenital, acquired, or medically induced.

Symptoms and Signs

The clinical presentation of Kaposi’s sarcoma varies depending on the disease form, immune status, and lesion location. However, the most characteristic symptoms include: 

• Skin Lesions – Appearing as purple, red, or brown spots, nodules, or plaques. These are most often found on the legs, face, trunk, and mucous membranes. Over time, they may grow, merge, ulcerate, or bleed.

• Mucosal Involvement – Especially seen in the epidemic (HIV-associated) form. Lesions may appear in the mouth, on the tongue, palate, or throat, causing pain or difficulty eating.

• Internal Organ Involvement – Seen in aggressive forms. Tumors may affect the lungs, gastrointestinal tract, or lymph nodes, leading to symptoms such as coughing up blood, shortness of breath, abdominal pain, diarrhea, or gastrointestinal bleeding.

• Lymphedema – Swelling of limbs or the face due to lymphatic vessel involvement, particularly in cases with extensive skin lesions.

Important: In immunocompromised patients, Kaposi’s sarcoma can progress very rapidly, making early diagnosis and prompt treatment crucial.

Diagnosis of Kaposi’s Sarcoma

Accurate diagnosis is essential to determine the most effective treatment plan and assess prognosis. Diagnostic steps include:

• Examination of skin and mucosal lesions;

• Biopsy of affected tissue followed by histological and immunohistochemical analysis to detect HHV-8;

• Laboratory tests, including immunogram and CD4 count;

Imaging and endoscopy, especially if internal organ involvement is suspected:

• Endoscopy (gastroscopy, colonoscopy) – to identify gastrointestinal lesions;

• CT or MRI of the chest and abdomen – to assess internal organ and lymph node involvement;

• Chest X-ray or CT – if lung involvement is suspected.

Proper diagnosis is vital to selecting the right treatment, particularly in HIV-positive patients or those with other forms of immune suppression.

Treatment of Kaposi’s Sarcoma

Treatment strategies depend on the disease form, extent, immune status (especially HIV status), and the presence of symptoms or internal involvement. Therapy can be local, systemic, or combined.

• Antiretroviral Therapy (ART) – For HIV-positive patients, ART is the foundation of treatment. In many cases, it leads to regression of Kaposi’s sarcoma without additional therapies. Restoring immune function helps suppress HHV-8 activity.

• Local Therapy – Used for limited skin lesions. Radiation therapy is effective for isolated sites, especially on the face, limbs, or mucous membranes. Cryotherapy, electrocautery, and laser ablation may be used for solitary nodules. Intralesional chemotherapy may be used for a small number of lesions.

• Systemic Chemotherapy – Indicated for widespread disease, internal organ involvement, or rapid progression. Combination regimens are often used, especially for aggressive forms.

• Immunotherapy – Interferon-alpha may be used as an adjunct for patients with moderately preserved immunity, particularly in early stages.

• Supportive and Symptomatic Care – Aims to manage secondary infections, control edema, pain, and other symptoms.

With proper treatment, Kaposi’s sarcoma can be effectively controlled—especially in patients on ART who are under regular medical supervision. 

Prognosis and Survival

The prognosis for Kaposi’s sarcoma depends on the disease form, the patient's general health, immune status (especially HIV status), disease extent, and treatment efficacy: 

• The classic form has a favorable prognosis with skin-only involvement;

• HIV-positive patients on ART may achieve long-term remission;

• Visceral or rapidly progressing forms are associated with lower survival rates.

Thanks to advances in oncology and the widespread availability of ART—including in Russia—five-year survival rates have significantly improved.

Prevention

While no specific vaccine exists, several measures can help reduce the risk of developing Kaposi’s sarcoma: 

• Early HIV detection and continuous treatment;

• Preventing HHV-8 infection (e.g., safe sex practices);

• Monitoring immune status in high-risk individuals;

• Managing comorbidities and minimizing immunosuppression in transplant patients.

The Marus medical treatment platform can assist in organizing care for Kaposi’s sarcoma in leading Russian medical institutions. We help select specialized clinics, find experienced oncologists who focus on tumor treatment, and coordinate each step of the medical journey with full support.