Commonly affected areas include the lower limbs, back, face, mouth, and genitalia. The lesions are usually as described above, but may occasionally be plaque-like (often on the soles of the feet) or even involved in skin breakdown with resulting fungating lesions.

Associated swelling may be from either local inflammation or lymphoedema (obstruction of local lymphatic vessels by the lesion). Skin lesions may be quite disfiguring for the sufferer, and a cause of much psychosocial pathology.

KS lesions are nodules or blotches that may be red, purple, brown, or black, and are usually papular.

They are typically found on the skin, but spread elsewhere is common, especially the mouth, gastrointestinal tract and respiratory tract. Growth can range from very slow to explosively fast, and is associated with significant mortality and morbidity.

Ewing's sarcoma is more common in males (1.6 male:1 female) and usually presents in childhood or early adulthood, with a peak between 10 and 20 years of age. It can occur anywhere in the body, but most commonly in the pelvis and proximal long tubular bones, especially around the growth plates. The diaphyses of the femur are the most common sites, followed by the tibia and the humerus. Thirty percent are overtly metastatic at presentation. Patients usually experience extreme bone pain.

Signs and symptoms include: intermittent fevers, anemia, leukocytosis, increased sedimentation rate, and other symptoms of inflammatory systemic illness. Also, depending on the type, progression, and location of the tumor, great pain may occur.

According to the Bone Cancer Research Trust (BCRT), the most common symptoms are: localized pain, swelling, and sporadic bone pain with variable intensity. The swelling is most likely to be visible if the sarcoma is located on a bone near the surface of the body, but when it occurs in other places deeper in the body, like on the pelvis, it may not be visible.

Synovial sarcoma usually presents with an otherwise asymptomatic swelling or mass, although general symptoms related to malignancies can be reported such as fatigue.

It presents as a slow growing mass that especially affects tendons and aponeuroses and it is deeply situated. Patients often perceive it as a lump or hard mass. It causes either pain or tenderness but only until it becomes large enough. This kind of tumor is commonly found in the extremities especially around the knee, feet and ankle. Patients diagnosed with clear cell sarcoma are usually between the ages of 20 and 40.

Ewing sarcoma or Ewing's sarcoma () is a malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. The most common areas in which it occurs are the pelvis, the femur, the humerus, the ribs and clavicle (collar bone).

Since a common genetic locus is responsible for a large percentage of Ewing sarcoma and primitive neuroectodermal tumors, these are sometimes grouped together in a category known as the Ewing family of tumors.

Ewing sarcoma occurs most frequently in teenagers and young adults, with a male/female ratio of 1.6:1.

Although usually classified as a bone tumor, Ewing's sarcoma can have characteristics of both mesodermal and ectodermal origin, making it difficult to classify.

James Ewing (1866–1943) first described the tumour, establishing that the disease was separate from lymphoma and other types of cancer known at that time.

A sarcoma is a cancer that arises from transformed cells of mesenchymal origin. Thus, malignant tumors made of cancellous bone, cartilage, fat, muscle, vascular, or hematopoietic tissues are, by definition, considered sarcomas. This is in contrast to a malignant tumor originating from epithelial cells, which are termed carcinoma. Human sarcomas are quite rare. Common malignancies, such as breast, colon, and lung cancer, are almost always carcinoma. The term is from the Greek "sarx" meaning "flesh".

A synovial sarcoma (also known as: malignant synovioma) is a rare form of cancer which occurs primarily in the extremities of the arms or legs, often in close proximity to joint capsules and tendon sheaths. As one of the soft tissue sarcomas, it is one of the rarest forms of soft tissue cancer.

The name "synovial sarcoma" was coined early in the 20th century, as some researchers thought that the microscopic similarity of some tumors to synovium, and its propensity to arise adjacent to joints, indicated a synovial origin; however, the actual cells from which the tumor develops are unknown and not necessarily synovial.

Primary synovial sarcomas are most common in the soft tissue near the large joints of the arm and leg but have been documented in most human tissues and organs, including the brain, prostate, and heart.

Synovial sarcoma occurs most commonly in the young, representing

about 8% of all soft tissue sarcomas but about 15–20% of cases occur in adolescents and young adults. The peak of incidence is in the third decade of life, with males being affected more often than females (ratio around 1.2:1).

There are few early warning signs that a patient has a DSRCT. Patients are often young and healthy as the tumors grow and spread uninhibited within the abdominal cavity. These are rare tumors and symptoms are often misdiagnosed by physicians. The abdominal masses can grow to enormous size before being noticed by the patient. The tumors can be felt as hard, round masses by palpating the abdomen.

First symptoms of the disease often include abdominal distention, abdominal mass, abdominal or back pain, gastrointestinal obstruction, lack of appetite, ascites, anemia, and/or cachexia.

Other reported symptoms include unknown lumps, thyroid conditions, hormonal conditions, blood clotting, kidney or urological problems, testicle, breast, uterine, vaginal, or ovarian masses.

The sarcoma first appears as a bruise mark, a purplish discoloration or a tender skin nodule in the extremity, typically on the anterior surface. It progresses to an ulcer with crusting, and finally to an extensive necrosis involving the skin and subcutaneous tissue. It metastasizes quickly.

When the tumor is large and there is presence of necrosis and local recurrence, the prognosis is poor. Presence of metastasis occurs in more than 50% cases and the common places of its occurrence are the bone, lymph node and lungs. Five-year survival rates, which are reported to be between 50-65%, can be misleading because the disease is prone to late metastasis or recurrence. Ten and twenty-year survival rates are 33% and 10%, respectively.

UPS occurs most commonly in the extremities and retroperitoneum, but has been reported in other sites. Metastasis occurs most frequently in the lungs (90%), bones (8%), and liver (1%).

In the extremities, it presents itself as a painless enlarging soft tissue mass.

Undifferentiated pleomorphic sarcoma (UPS), also undifferentiated pleomorphic sarcoma (PUS) and previously malignant fibrous histiocytoma (abbreviated MFH), is a type of cancer and soft tissue sarcoma.

It is considered a diagnosis of exclusion for sarcomas that cannot be more precisely categorized. Other sarcomas are cancers that form in bone and soft tissues, including muscle, fat, blood vessels, lymph vessels, and fibrous tissue (such as tendons and ligaments).

Dermatofibrosarcoma protuberans can begin as a minor firm area of skin most commonly about to 1 to 5 cm in diameter. It can resemble a bruise, birthmark, or pimple. It is a slow growing tumor and is usually found on the torso but can also be found on the arms, legs, head and neck. About 90% of DFSPs are low grade sarcomas. About 10% are mixed; they contain a high-grade sarcomatous component (DFSP-FS); therefore, they are considered to be intermediate-grade sarcomas. DFSPs rarely lead to a metastasis (fewer than 5% do metastasise), but DFSPs can recur locally. DFSPs most often arise in patients who are in their thirties, but sometimes have been described in children or the elderly.

Dermatofibrosarcoma protuberans (DFSP)

is a very rare tumor. It is a rare neoplasm of the dermis layer of the skin, and is classified as a sarcoma. There is only about one case per million per year. DFSP is a fibrosarcoma, more precisely a cutaneous soft tissue sarcoma. In many respects, the disease behaves as a benign tumor, but in 2–5% of cases it can metastasize, so it should be considered to have malignant potential. It occurs most often in adults in their thirties; it has been described congenitally, in children, and the elderly. It accounts for approximately 2–6% of soft tissue sarcoma cancers.

Langerhans cell sarcoma is a form of malignant histiocytosis. It should not be confused with Langerhans cell histiocytosis, which is cytologically benign. Langerhans cell sarcoma is known to transform into leukemia. It can present in the lung, but such cases are rare.

In their early stages, soft-tissue sarcomas usually do not cause symptoms. Because soft tissue is relatively elastic, tumors can grow rather large, pushing aside normal tissue, before they are felt or cause any problems. The first noticeable symptom is usually a painless lump or swelling. As the tumor grows, it may cause other symptoms, such as pain or soreness, as it presses against nearby nerves and muscles. If in the abdomen it can cause abdominal pains commonly mistaken for menstrual cramps, indigestion, or cause constipation.

In general, epithelioid sarcoma is a slow-growing and relatively painless tumor, often resulting in a lengthy period of time between presentation and diagnosis. Due to its ambiguity, it is often misdiagnosed, mistaken as a persistent wart or cyst. It most commonly presents itself in the distal limbs (fingers, hands, forearms, or feet) as a small, soft mass or a series of bumps. It is most often described as a firm-to-hard palpable mass, either in the deep soft tissue or in the dermis. Often, superficial lesions will ulcerate causing a mistaken diagnosis of a poorly healing traumatic wound or wart. About 13% of patients will present with multifocal tumors, and about 13% of patients will present with metastatic disease.

Sarcomas are given a number of different names based on the type of tissue that they most closely resemble. For example, osteosarcoma resembles bone, chondrosarcoma resembles cartilage, liposarcoma resembles fat, and leiomyosarcoma resembles smooth muscle.

Mast cell sarcoma is an extremely aggressive form of sarcoma made up of neoplastic mast cells. A sarcoma is a tumor made of cells from connective tissue. Mast cell sarcoma is an extremely rare tumor. Only 3 cases are reported so far. Prognosis is extremely poor. People with a mast cell sarcoma have no skin lesions, and pathology examination of the tumor shows it to be very malignant with an aggressive growth pattern. Mast cell sarcoma should not be confused with

extracutaneous mastocytoma, a rare benign mast cell tumor without destructive growth. In the cases observed, mast cell sarcoma terminated quickly as mast cell leukemia; one of the most aggressive human cancers.

Desmoplastic small-round-cell tumor is an aggressive and rare cancer that primarily occurs as masses in the abdomen. Other areas affected may include the lymph nodes, the lining of the abdomen, diaphragm, spleen, liver, chest wall, skull, spinal cord, large intestine, small intestine, bladder, brain, lungs, testicles, ovaries, and the pelvis. Reported sites of metastatic spread include the liver, lungs, lymph nodes, brain, skull, and bones.

The tumor is classified as a soft tissue sarcoma. It is considered a childhood cancer that predominantly strikes boys and young adults. The disease rarely occurs in females, but when it does the tumors can be mistaken for ovarian cancer.

In dogs, mast cell tumors are the most frequent round cell tumor.

Histiocytic sarcoma is a tumor derived from histiocytes. The tumor is often positive for CD163 and can appear in the thyroid. However, in some cases it can also appear in the brain.

Lymphangiosarcoma is a rare malignant tumor which occurs in long-standing cases of primary or secondary lymphedema. It involves either the upper or lower lymphedematous extremities but is most common in upper extremities. Although its name implies lymphatic origin, it is believed to arise from endothelial cells and may be more accurately referred to as angiosarcoma.

Epithelioid sarcoma is a rare soft tissue sarcoma arising from Mesenchyme tissue and characterized by epithelioid-like features. It accounts for less than 1% of all soft tissue sarcomas. It was first clearly characterized by F.M. Enzinger in 1970. It commonly presents itself in the distal limbs (fingers, hands, forearms, or feet) of young adults as a small, soft mass or a series of bumps. A proximal version has also been described, frequently occurring in the upper extremities. Rare cases have been reported in the pelvis, vulva, penis, and spine.

Histologically, epithelioid sarcoma forms nodules with central necrosis surrounded by bland, polygonal cells with eosinophilic cytoplasm and peripheral spindling. Epithelioid sarcomas typically express vimentin, cytokeratins, epithelial membrane antigen, and CD34, whereas they are usually negative for S100, desmin, and FLI-1. They typically stain positive for CA125.

Epithelioid sarcoma most commonly strikes young adults, yet no age group is immune. The disease has a tendency to develop local recurrences and metastasis thereafter to regional lymph nodes, lung, bone, brain, and other locations, including the scalp. Generally speaking, epithelioid sarcoma has a high rate of relapse after initial treatment and tends to recur locally (at or near the original tumor site). Epithelioid sarcoma also demonstrates lymphatic spread (in 22-48% of cases), and metastasis (in 21-63% of cases). These events, as well as advanced stage (progression) and grade (aggressiveness), are predictive of an overall worse outcome. The overall five-year survival rate for epithelioid sarcoma is anywhere from 25 to 78%. Importantly, the 10-year and 15-year survival rate drops off significantly. Associated with a more positive outcome are younger age, female vs. male sex, distal vs. proximal location, smaller tumor size, and negative margins upon tumor resection.

ASPS may exist in the patient’s body for a long time before being diagnosed. It can grow large and push aside surrounding tissues for a long time before causing any discomfort. Therefore, ASPS symptoms may either be a painless swelling, or a soreness caused by compressed nerves or muscles, affecting the range of motion in the area.