Related articles: Kaposi's sarcoma
Definition
Kaposi's sarcoma is a malignant tumor of endothelial cells, which cover the inside of blood or lymphatic vessels. The transformation of these cells into a neoplastic sense seems to depend on the response to human herpesvirus infection 8 (HHV8).
Immunosuppression markedly increases the risk of developing Kaposi's sarcoma. The tumor, in fact, is particularly frequent in patients already infected with the HIV virus and sometimes represents the first manifestation of AIDS.
Kaposi's sarcoma is distinguished in classical form, associated with AIDS, endemic or iatrogenic.
Classical (or Mediterranean) Kaposi's sarcoma appears more often in elderly men; usually, it causes little damage to the skin and mucous membranes and is not lethal; however, people who are affected have a predisposition to develop other malignancies.
Instead, Kaposi's sarcoma linked to AIDS (epidemic) is more aggressive; it causes multiple lesions to the face and trunk, with lymphatic and gastrointestinal involvement.
Endemic (or African) Kaposi 's sarcoma typically concerns the populations of equatorial Africa; it can run in a similar way to the classical form or determine a fulminant and fatal multi-systemic involvement (prepubertal lymphadenopathic form).
Iatrogenic Kaposi's sarcoma (from immunodepression) develops in people who have undergone organ transplantation and have a particularly weakened immune system.
Most common symptoms and signs *
- Asthenia
- Dyspnoea
- Edema
- hemoptysis
- Gastrointestinal hemorrhage
- macules
- Nodule
- plaques
- itch
Further indications
In general, Kaposi's sarcoma can occur in the skin, mucous membranes and internal organs.
The uncontrolled proliferation of endothelial cells causes the appearance of purplish or reddish skin spots in different areas of the body. These lesions are generally asymptomatic, but can flow into plaques and nodules. Sometimes itching and edema can occur.
The mucosal lesions, on the other hand, appear as macules, plaques and bluish nodules tending to purple.
In classical Kaposi's sarcoma, the lesions occur mainly in the lower limbs. In the epidemic form of the tumor, however, these appear in the upper part of the body and on the mucous membranes, then spread and cover large areas of the skin.
When Kaposi's sarcoma involves internal organs, symptoms vary depending on the organ concerned (eg bleeding in the intestine, difficulty breathing if it affects the lungs, etc.).
The diagnosis is formulated by performing a biopsy of the suspected lesion, followed by microscopic analysis to confirm the presence of tumor cells. A CT scan or chest X-ray, a bronchoscopy or a gastrointestinal endoscopy, allow instead to evaluate the possible spread to the internal organs.
The treatment of asymptomatic superficial lesions includes surgical removal, cryotherapy or diathermocoagulation. Radiation therapy is used for multiple lesions or lymphatic disease.
In forms associated with AIDS, antiretroviral drugs give the best result. In transplanted patients, Kaposi iatrogenic sarcoma responds best with dose reduction or suspension of immunosuppressive therapy. The treatment of endemic Kaposi's sarcoma is typically palliative.
