Soft tissue sarcoma is a malignant tumor affecting cells found in soft tissues in the body. Soft tissue includes muscles, tendons, connective tissues, fat, blood vessels, nerves, and synovial (joint) tissues. In this case, the sarcoma arises in the sheath covering the nerves, or is stimulated by nerve tissue. Soft-tissue sarcomas of neurogenic origin most frequently (60%) affect the peripheral nerve sheaths in the upper extremities (arms), lower extremities (legs) or trunk of the body. Furthermore, the lower extremities are involved three times more often than the upper extremities.

A malignant neoplasm may be caused by a variety of elements such as chemicals, radiation agents, biologic agents such as viruses, and dietary factors. However, exposure to radiation, including therapeutic, diagnostic, and accidental accounts for fewer than 5% of sarcomas. The most common cause of radiation exposure in patients who develop sarcomas is from radiation given to treat other tumors, such as breast cancer or lymphoma. The average time between radiation exposure and diagnosis of a sarcoma is about 10 years. Moreover, heredity, history of angiosarcoma of the liver, a weak or poorly-functioning immune system, and damaged lymph nodes are also considered possible etiological factors.

Environmental or occupational exposures to certain chemicals (i.e. asbestos, polyvinyl chloride, androgens, and arsenic) have been established as risk factors for sarcoma. Exposure to the defoliant, dioxin (Agent Orange), chlorophenols, or agricultural herbicide has been linked to the development of soft tissue sarcomas in some studies.

Patients with soft tissue sarcomas usually present with a painless, palpable mass on the extremities or the trunk. Forty percent of soft tissue sarcomas develop in the lower extremity, about 30% in the trunk and retroperitoneum, 15% in the upper extremities, and 15% in the head and neck. Intra-abdominal and retroperitoneal primary lesions may cause pain and weight loss from invasion or displacement of organs. The duration of symptoms before diagnosis ranges from a few weeks to decades, with a median of 1 to 3 months.

In the early stages, a sarcoma is small and does not produce symptoms. As the tumor grows, it may push aside normal body structures, causing symptoms. The most common symptom of a sarcoma is a lump or swelling that may or may not be painful. Symptoms vary, depending on the part of the body that is affected. However, soft tissue sarcomas that arise from or are stimulated by nerve tissues in the arm or leg may cause pain or soreness, and an uncomfortable swelling in the affected limb; affected nerves in the lung may cause cough and breathlessness; in the bowel: abdominal pain, vomiting, and constipation; and in the uterus: bleeding from the vagina and pain in the pelvis or lower abdomen.

A complete history and physical examination are necessary for early diagnosis and treatment. X-ray; magnetic resonance imaging (MRI); computed tomography (CT) scan; bone scan; ultrasonography; blood studies; tumor markers; tissue biopsy and tumor staging may be required.

Early treatment may be aggressive and offer a more favorable prognosis. The selection of treatment is determined by the grade of the tumor and tissue involved. Aggressive treatment may include surgical removal of the cancerous tumor and nearby tissues, and possibly nearby lymph nodes. For certain types of sarcoma, amputation may be performed. Chemotherapy or radiation treatments may be necessary and depending on the tumor grade, a combination of these treatments may be used.

The outcome depends on the patient's age, the size, grade, and stage of the tumor, the type and extent of tissues involved, the treatment employed, as well as any metastasis throughout the body. Other complications of treatment include: local recurrence, wound complications, nerve or blood vessel injury associated with treatment, pathologic fracture of adjacent bone following radiation therapy, and the need for amputation regardless of treatment. Muscle weakness or muscle deformity may result, and there may be an alteration in self-image. In addition, counseling, psychotherapy, and support groups may be indicated to assist the patient in dealing with the diagnosis.

• If the Veteran is a former prisoner of war and was interned or detained for not less than 30 days, this disease shall be service connected if manifest to a degree of disability of 10% or more at any time after discharge or release from active military, naval, or air service even though there is no record of such disease during service, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied [38 CFR 3.309(c) Disease subject to presumptive service connection].

• If the Veteran was exposed to an herbicide agent during active military, naval, or air service, this disease shall be service-connected if the requirements of 38 CFR 3.307(a)(6) are met even though there is no record of such disease during service, provided further that the rebuttable presumption provisions of 38 CFR 3.309(e). Disease subject to presumptive service connection.

• This disability shall be granted service connection although not otherwise established as incurred in or aggravated by service if manifested to a compensable degree within the applicable time limits under 38 CFR 3.307 following service in a period of war or following peacetime service on or after January 1, 1947, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• The 100 percent rating will be continued for 6 months following the cessation of surgical, X-ray, antineoplastic chemotherapy or other therapeutic procedure. At this point, if there has been no local recurrence or metastases, the rating will be made on residuals.