In the mouth, the hard palate is most frequently affected, followed by the gums. Lesions in the mouth may be easily damaged by chewing and bleed or develop secondary infection, and even interfere with eating or speaking. Gastrointestinal tract
Involvement can be common in those with transplant-related or AIDS-related KS, and it may occur in the absence of skin involvement. The gastrointestinal lesions may be silent or cause weight loss, pain, nausea/vomiting, diarrhea, bleeding (either vomiting blood or passing it with bowel movements), malabsorption, or intestinal obstruction. Respiratory tract
Involvement of the airway can present with shortness of breath, fever, cough, coughing up blood or chest pain, or as an incidental finding on chest x-ray. The diagnosis is usually confirmed by bronchoscopy, when the lesions are directly seen and often biopsied. Kaposis sarcoma of the lung has a poor prognosis. Cause
Kaposis sarcoma-associated herpesvirus (KSHV), also called HHV-8, is present in almost 100% of Kaposi sarcoma lesions, whether HIV-related, classic, endemic, or iatrogenic. KSHV encodes oncogenes, microRNAs and circular RNAs that promote cancer cell proliferation and escape from the immune system. Transmission
In Europe and North America, KSHV is transmitted through saliva. Thus, kissing is a risk factor for transmission. Higher rates of transmission among gay and bisexual men have been attributed to "deep kissing" sexual partners with KSHV. Another alternative theory suggests that use of saliva as a sexual lubricant might be a major mode for transmission.
Diagnosed as definite or possible but limited to one limb or ≤5 contiguous segments of spine.Another set of criteria are:

Two or more nonintradermal (cutaneous) schwannomas
No evidence of vestibular tumor
No known NF-2 mutationor

One pathologically confirmed nonvestibular schwannoma plus a first degree relative who meets the above criteria. Treatment
Schwannomatosis patients represent 2.4% to 5% of patients undergoing surgical resection of their schwannomas. In isolated regions of the body schwannomas are small and difficult to locate. Intraoperative sonography offers invaluable assistance in such cases by localizing small schwannomas and decreasing operative time and extent of the surgical incision. If feasible, the schwannomas can be surgically removed. Any tumor-associated pain usually subsides after tumor removal. Damaged nerves and scar tissue can be a result of surgery and pain can be an ongoing problem. Sometimes, a tumor will reappear at the same site after surgery. If surgery is unfeasible, then pain management will have to be used. Schwannomatosis can sometimes cause severe, untreatable pain over time. Other than surgery and/or pain management, there are no other medical treatments available. There are no drugs available to treat Schwannomatosis. Gamma knife radiosurgery can be performed on head tumors to help stop growth of a tumor, although there is no guarantee that it will work. The University of Pittsburgh published their experience with over 829 cases and reported 97% of patients had long term tumor control (defined as requiring no further treatment) with Gamma knife radiosurgery. Recently, many advances are being made in the treatment of schwannomas. Of interest is CyberKnife, manufactured by Accuray.