It has been known for decades that immunocompromised persons are at risk for developing cancers. Therefore it is not surprising that HI V-infected individuals who have been immunodeficient for varying periods of time have an increased chance to develop malignancies. The most frequent is Kaposi's sarcoma, and non-Hodgkin's lymphomas show the fastest increasing prevalence. There also appears to be an increased risk to develop Hodgkin's lymphoma. Additionally, HIV-infected children are also at risk to develop malignancies.
KS is a malignant reactive lesion, stemming from factors (cytokines) that induce the formation of tumors in widespread tissues and organs; The most prominent feature is produced by an angiogenesis factor, which in turn leads to the characteristic appearance of a vascular lesion.
While there has been a well-known endemic form of KS, occurring mainly in Africa and the northern Mediterranean area, epidemic KS associated with HIV immunodeficiency is much more lethal. Outside of immunosuppression, an exact etiology and all involved factors are unknown. Because KS is a reactive type lesion, it is often considered a pseudomalignancy. KS can involve organs and be the cause of death, but most deaths in KS patients are due to opportunistic infections and the progressive wasting syndrome.
In the United States about 15% of all reported AIDS cases have KS as one of their AIDS-defining diseases. Although KS occurs in all AIDS groups, it is more frequent in homosexual and bisexual males, indicating special co-factors that may be preferentially transmitted by anal sex. The mean time of survival after the diagnosis of KS is about 2 years .
Skin is the most common site of KS, but about half of patients will have oral KS. In many of these patients, oral KS may be the first or even the only manifestation. KS can afflict any oral mucosal site, with the palate being the most frequent and gingiva the second.
Initial manifestations appear as flat, red-purple, asymptomatic lesions. But since KS is a reactive response to cellular growth factors, the lesions increase in number and size, becoming nodular and symptomatic. KS can dramatically affect quality of life by esthetic blemishes, pain, bleeding, and interference with mouth functions.
Because of the variable clinical features, the differential diagnosis of KS can include hemangiomas, purpuric changes, and nonspecific inflammation. Bacillary angiomatosis can have a similar appearance, but this primarily cutaneous infection, caused by Rochalimaea bacteria, rarely occurs in oral mucosa. Diagnosis of KS is made by biopsy findings, which include connective tissue changes of vascular and fibrous proliferations and extravasation of red blood cells.
When lesions are widespread, systemic chemotherapy is helpful. For oral lesion that are well localized, intralesional injections (the cytotoxic drug, vinblastine, or the sclerosing agent, sodium tetradecyl sulfate) are effective. Surgery is possible but not recommended. For more extensive oral involvement, low-dose radiation has been useful (total dosages usually do not exceed 1500 cOy). In any case, treatment objectives are to reduce signs and symptoms and are almost never curative. Again, the choice of treatment depends on patient desires, cost, time, and other criteria for compliance. While treatment of oral KS can improve quality of life, there is no indication that it alters survival.
As expected, the occurrence of NHL continues to increase as the number of HIV-infected people grows and their longevity extends. Inappropriate B-lymphocyte stimulation and the presence of Epstein-Barr virus play a role, but all the co-factors are poorly understood.
Frequently these lymphomas are extranodal and can involve the mouth. In some cases, oral NHL has been either the first or the only evidence of NHL tumor. Oral NHL can appear as masses or ulcerative lesions. This diversity of appearance again mandates an imaginative differential diagnosis, so that significant lesions will be properly diagnosed and managed. Biopsy is necessary for a definitive diagnosis, classification, staging, and treatment. While KS is a more common malignancy in gay men, NHL is more common in HIY heterosexual drug users.
Treatment must be aggressive for optimal results. Two-year survival rates are poor, approximating 20%. Multiple cytotoxic drugs offer the best results. This added immunosuppression obviously increases the complications during and after therapy. These complications include other oral diseases, such as thrush, aphthous-like lesions, and lichenoid reactions.
Oral squamous carcinoma usually occurs beyond the fourth decade in life, with the mean age being about 62. However, in the HIV patient, squamous carcinomas have been diagnosed not too infrequently, and the mean age has been in the third decade of life. These occurrences indicate that oral squamous carcinoma is probably an HIV-associated malignancy. The characteristics have been rapid growth and poor therapeutic responses to both radiation and surgery.
These carcinomas seem to arise de novo without evidence of premalignant changes, such as leukoplakia or erythroplakia. While the tongue appears to be the most common intraoral site, there has been no association with oral hairy leukoplakia. However. co-factors seem to include histories of smoking and alcohol habits. Viral influence on proto-oncogenes, growth factors, and suppressor proteins has not been established.