Kaposi sarcoma ( KS ) is a type of cancer that can form mass in the skin, lymph nodes, or other organs. Skin lesions are usually purple. They can occur singly, in limited areas, or are widespread. This can get worse gradually or quickly. Lesions can be flat or elevated. Human herpesvirus 8 (HHV8) is found in the lesions of all affected persons. Risk factors include poor immune function, either as a result of disease or certain drugs, and chronic lymphedema.
Four sub-types are described: classical, endemic, immunosuppressed-related, and epidemic. The classic KS tends to affect older men, grows slowly, and affects the feet. KS is endemic in young adult males in Africa and can be more aggressive. KS associated with immunosuppression generally occurs in people who follow organ transplants and mostly affect the skin. KS epidemic occurs in people with AIDS and many parts of the body can be affected. The diagnosis is with tissue biopsy while the extent of the disease can be determined by medical imaging.
Treatment is based on sub-types, whether the condition is localized or extends, and a person's immune function. Local skin lesions can be treated by surgery, chemotherapy injection into lesions, or radiation therapy. Widespread disease can be treated with chemotherapy or biological therapy. In those with HIV/AIDS, highly active antiretroviral therapy (HAART) prevents and often treats KS. In some cases, additional chemotherapy may be necessary. With widespread disease, death can occur.
This condition is relatively common in people with HIV/AIDS and after organ transplants in 2017. More than 35% of people with AIDS may be affected. It was first described by Moritz Kaposi in 1872. He became better known as one of the AIDS-defining illnesses of the 1980s. The viral link to this cancer was discovered in 1994.
Video Kaposi's sarcoma
Signs and symptoms
KS lesions are nodules or spots that may be red, purple, brown, or black, and are usually papular.
They are usually found in the skin, but spread elsewhere is common, especially the mouth, digestive tract and respiratory tract. Growth can range from very slow to very fast, and is associated with significant mortality and morbidity.
Skin
Areas often affected include lower limbs, back, face, mouth, and genitalia. Lesions are usually as described above, but can sometimes be like plaques (often on the soles of the feet) or even engage in skin damage with lesions that produce fungating. The associated swelling may be from local inflammation or lymphoedema (obstruction of local lymphatic vessels by lesions). The skin lesions may be quite damaging to the sufferer, and cause many psychosocial pathologies.
Mouth
The mouth is involved in about 30% of cases, and is the starting place in 15% of AIDS-related KS. Inside the mouth, the hard palate is most commonly affected, followed by the gums. Lesions in the mouth can be easily damaged by chewing and bleeding or suffering from secondary infections, and even interfere with eating or talking.
Gastrointestinal tract
Involvement can be common in those who are associated with transplantation or AIDS-related KS, and can occur in the absence of skin involvement. Gastrointestinal lesions may be silent or cause weight loss, pain, nausea/vomiting, diarrhea, bleeding (either vomiting blood or passing through bowel movements), malabsorption, or bowel obstruction.
Respiratory
Airway involvement may present with shortness of breath, fever, cough, hemoptysis (coughing of blood), or chest pain, or as an incidental finding on chest x-rays. Diagnosis is usually confirmed by bronchoscopy when the lesion is directly visible, and often biopsied. Kaposi's sarcoma in the lungs has a poor prognosis.
Maps Kaposi's sarcoma
Cause
The sarcophage-related sarcoma sarcoma (KSHV), also called HHV-8, is present in nearly 100% of Kaposi's sarcoma lesions, whether HIV-related, classical, endemic, or iatrogenic.
Transmission
In Europe and North America, KSHV is transmitted through saliva. Thus, kissing is a theoretical risk factor for transmission. High rates of transmission among gay and bisexual men have been associated with sexual partners "deep kiss" with KSHV. Another alternative theory suggests that the use of saliva as a sexual lubricant may be the main mode of transmission. Wise advice is to use commercial lubricants when needed and avoid deep kisses with partners with KSHV infection or whose status is unknown.
KSHV can also be transmitted through organ transplants and blood transfusions. Testing for viruses before this procedure is likely to effectively limit iatrogenic transmission.
Classification
HHV-8 is responsible for all KS varieties. Since Moritz Kaposi first described this cancer, the disease has been reported in five separate clinical settings, with different presentations, epidemiology, and prognosis. All of these forms are infected with KSHV and are different manifestations of the same disease but have differences in clinical aggressiveness, prognosis and treatment.
- Classical Kaposi sarcoma most often appears at the beginning of the toes and soles of the feet as a macula and reddish, violaceous, or bluish-black spots that spread and unite to form nodules or plaques. A small proportion of these patients may have visceral lesions. In most cases, treatment involves surgical removal of the lesion. This condition tends to be slow and chronic, affecting elderly men from the Mediterranean region, Arab countries or Eastern European descent. Countries bordering the Mediterranean basin have higher rates of KSHV/HHV-8 infection than the rest in Europe.
- KS Endemic , which has two types. Although this may be present throughout the world, it was initially described later in young Africans, especially from sub-Saharan Africa. This variant is not associated with HIV infection and is a more aggressive disease that infects the skin widely.
- Aggressive African lymphadenopathic sarcoma, occurs in children younger than 10 years, presenting with lymph node involvement, with or without skin lesions.
- Skin cutaneous sarcoma is present with nodular, infiltrative, vascular mass in the extremities, mostly in men between the ages of 20 and 50, and endemic in tropical Africa.
- Immunosuppression-associated Kaposi sarcoma has been described, but only rarely until the emergence of calcineurin inhibitors (such as ciclosporines, which are T-cell function inhibitors) for transplant patients in the 1980s, when the incidence developed rapidly. The tumor appears well when an organ infected with HHV 8 is transplanted to someone who has not been exposed to the virus or when the transplant recipient has stored an existing HHV 8 infection. Unlike classic Kaposi sarcoma, the presentation is more varied. AIDS-related sarcoma sarcoma typically presents with skin lesions that begin as one or several red macules to purple-red, rapidly evolving into papules, nodules, and plaques, with predilection for the head, bone back, neck, trunk, and mucous membranes. In more advanced cases, they can be found in the stomach and intestines, lymph nodes, and lungs. KS-AIDS stimulated the greatest interest as one of the first AIDS-related diseases, and was first described in 1981. This is more than 300 times more common in AIDS patients than kidney transplant recipients. In this case, HHV 8 is sexually transmitted among people who are also at risk of sexually transmitted HIV.
Pathology
Despite its name, it is generally not considered a true sarcoma, which is a tumor arising from mesenchymal tissue. KS histogenesis remains controversial. KS may appear as lymphatic endothelium cancer and form a vascular duct that fills blood cells, providing tumors with characteristics such as bruising appearance. KSHV proteins are uniformly detected in KS cancer cells.
KS lesions contain tumor cells with abnormally longitudinal shape characteristics, called spindle cells . The most characteristic feature of Kaposi's sarcoma is the presence of spindle cells that form crevices that contain red blood cells. The activity of mitosis is only moderate and pleomorphism is usually absent. This tumor is highly vascular, contains abnormal and irregular blood vessels, which secrete red blood cells to surrounding tissues and gives dark tumors of color. Inflammation around the tumor can cause swelling and pain. Various positive body-sized hyaline PAS are often seen in the cytoplasm or sometimes extracellular.
The sarcoma Kaposi spindel cells differentiate against endothelial cells, possibly lymph vessels rather than natural blood vessels. Consistent immunoactivity for podoplanin supports the nature of lymphatic lesions.
Diagnosis
Although KS may be suspected from the appearance of lesions and risk factors of the patient, a definite diagnosis can be made only by biopsy and microscopic examination. Detection of KSHV LANA protein in tumor cells confirms the diagnosis.
In differential diagnosis, arteriovenous malformations, pyogenic granulomas and other vascular proliferation can be microscopically confusing with KS.
Prevention
Blood tests for the detection of antibodies against KSHV have been developed and can be used to determine whether a person is at risk of transmitting the infection to their sexual partner, or whether an organ is infected before the transplant. However, this test is not available except as a research tool, and, as such, there is little screening for people at risk of being infected with KSHV, such as people following transplantation.
Treatment
Kaposi's sarcoma can not be cured, but it can often be treated for years. In KS associated with immunodeficiency or immunosuppression, treating the cause of immune system dysfunction may slow or halt the development of KS. At 40% or more of people with AIDS-related Kaposi's sarcoma, Kaposi's lesion will shrink after starting highly active antiretroviral therapy (ART). Therefore, HAART is regarded as the cornerstone of therapy in AIDS-related Kaposi's sarcoma. However, in a certain percentage of such people, Kaposi's sarcoma may recur after several years on ART, especially if HIV is not completely depressed.
People with multiple local lesions can often be treated with local measures such as radiation therapy or cryosurgery. Weak evidence suggests that antiretroviral therapy in combination with chemotherapy is more effective than either of these two treatments individually. Limited evidence and clinical evidence suggests that topical beta-blockers, such as timolol, can induce regression of local lesions in classic Kaposi's sarcoma as well as HIV-related. In general, surgery is not recommended, as Kaposi's sarcoma may appear on the wound edges. In general, wider diseases, or diseases affecting internal organs, are treated with systemic therapy with interferon alpha, liposomal anthracyclines (such as doxorubicin liposomal or daunorubicin), thalidomide, or paclitaxel.
Epidemiology
With the decline in mortality rates among people with HIV/AIDS who received new treatments in the 1990s, the rate and severity of the KS epidemic also declined. However, the number of people living with HIV/AIDS is increasing in the United States, and it is possible that the number of people with AIDS-related Kaposi's sarcoma will increase again because these people live longer with HIV infection.
Awareness
It has been reported that only 6% of men who have sex with men are aware that KS is caused by a virus different from HIV. Thus, there is little public effort to prevent KSHV infection. Similarly, there is no systematic filtering of organ donations in place.
In people with AIDS, Kaposi's sarcoma is considered an opportunistic infection, a disease that can gain a foothold in the body because the immune system has weakened. With the rise in HIV/AIDS in Africa, where KSHV is widespread, KS has become the most frequently reported cancer in some countries.
Due to its highly visible nature, external lesions are sometimes a symptom of AIDS. Kaposi sarcoma entered the public consciousness by releasing the film Philadelphia , where the main character was fired after her employer learned she was HIV-positive because of the visible lesions. By the time KS lesions appear, the likelihood of the immune system is very weak.
References
External links
- Photo library of Kaposi sarcoma in Dermnet
- Kaposi Sarcoma Information
- The Office of HIV and AIDS Malignancies at the National Cancer Institute
- 3D macromolecule structure of Kaposi Sarcoma virus from EM Data Bank (EMDB)
- Cancer.Net Sarcoma - Kaposi
Source of the article : Wikipedia
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