Extraskeletal chondroma (also known as "Chondroma of soft parts") is a cutaneous condition, a rare benign tumor of mature cartilage.

The annual incidence rates per million for ameloblastomas are 1.96, 1.20, 0.18 and 0.44 for black males, black females, white males and white females respectively. Ameloblastomas account for about one percent of all oral tumors and about 18% of odontogenic tumors. Men and women tend to be equally affected, although women tend to be 4 years younger than men when tumors first occur and tumors appear to be larger in females.

Recurrence is common, although the recurrence rates for block resection followed by bone graft are lower than those of enucleation and curettage. Follicular variants appear to recur more than plexiform variants. Unicystic tumors recur less frequently than "non-unicystic" tumors. Persistent follow-up examination is essential for managing ameloblastoma. Follow up should occur at regular intervals for at least 10 years. Follow up is important, because 50% of all recurrences occur within 5 years postoperatively. Recurrence within a bone graft (following resection of the original tumor) does occur, but is less common. Seeding to the bone graft is suspected as a cause of recurrence. The recurrences in these cases seem to stem from the soft tissues, especially the adjacent periosteum. Recurrence has been reported to occur as many as 36 years after treatment.

To reduce the likelihood of recurrence within grafted bone, meticulous surgery with attention to the adjacent soft tissues is required.

A chondroma is a benign cartilaginous tumor, which is encapsulated with a lobular growing pattern.

Tumor cells (chondrocytes, cartilaginous cells) resemble normal cells and produce the cartilaginous matrix (amorphous, basophilic material).

Characteristic features of this tumor include the vascular axes within the tumor, which make the distinction with normal hyaline cartilage.

Based upon location, a chondroma can be described as an enchondroma or ecchondroma.

- enchondroma - tumor grows within the bone and expands it.

- ecchondroma - grows outward from the bone and this is rare.

Treatment

- best left alone

- if it causes fractures (enchondroma) or is unsightly it should be removed by curettage and the defect filled with bone graft.

An ecchondroma is a type of chondroma that is subperiosteal. A proliferation is known as "ecchondrosis".

The disease has been reported to affect 3 per 1000 infants younger than 6 months in the United States. No predilection by race or sex has been established. Almost all cases occur by the age of 5 months. The familial form is inherited in an autosomal dominant fashion with variable penetrance. The familial form tends to have an earlier onset and is present at birth in 24% of cases, with an average age at onset of 6.8 weeks. The average age at onset for the sporadic form is 9–11 weeks.

Cortical hyperostosis is a potential side effect of long-term use of prostaglandins in neonates.

ASPS is an extremely rare cancer. While sarcomas comprise about 1% of all newly diagnosed cancers, and 15% of all childhood cancers, ASPS comprises less than 1% of sarcomas. According to the American Cancer Society, about 9530 new cases of soft tissue sarcoma will be diagnosed in the USA in 2006. This predicts under 100 new cases of ASPS. Such low numbers of occurrence seriously impede the search for a cure by making it hard to gather any meaningful statistics about the disease. As a result, finding the best treatment option often involves making a lot of educated guesses.

Granular cell tumor is a tumor that can develop on any skin or mucosal surface, but occurs on the tongue 40% of the time.

It is also known as Abrikossoff's tumor, Granular cell myoblastoma, Granular cell nerve sheath tumor, and Granular cell schwannoma.)

Work out of Huntsman Cancer Institute (HCI) in Utah has demonstrated that ASPS might be driven in part by lactate both being used as a fuel and driving angiogenesis.

Undifferentiated pleomorphic sarcoma is regarded as the most common soft tissue sarcoma of late adult life. It rarely occurs in children. It occurs more often in Caucasians than in those of African or Asian descent and is a male-predominant disease, afflicting two males for every female.

The primary method for treatment is surgical, not medical. Radiation and chemotherapy are not needed for benign lesions and are not effective for malignant lesions.

Benign granular cell tumors have a recurrence rate of 2% to 8% when resection margins are deemed clear of tumor infiltration. When the resection margins of a benign granular cell tumor are positive for tumor infiltration the recurrence rate is increased to 20%. Malignant lesions are aggressive and difficult to eradicate with surgery and have a recurrence rate of 32%.

Most soft-tissue sarcomas are not associated with any known risk factors or identifiable cause. There are some exceptions:

- Studies suggest that workers who are exposed to chlorophenols in wood preservatives and phenoxy herbicides may have an increased risk of developing soft-tissue sarcomas. An unusual percentage of patients with a rare blood vessel tumor, angiosarcoma of the liver, have been exposed to vinyl chloride in their work. This substance is used in the manufacture of certain plastics, notably PVC.

- In the early 1900s, when scientists were just discovering the potential uses of radiation to treat disease, little was known about safe dosage levels and precise methods of delivery. At that time, radiation was used to treat a variety of noncancerous medical problems, including enlargement of the tonsils, adenoids, and thymus gland. Later, researchers found that high doses of radiation caused soft-tissue sarcomas in some patients. Because of this risk, radiation treatment for cancer is now planned to ensure that the maximum dosage of radiation is delivered to diseased tissue while surrounding healthy tissue is protected as much as possible.

- Kaposi's sarcoma, a rare cancer of the cells that line blood vessels in the skin and mucus membranes, is caused by Human herpesvirus 8. Kaposi's sarcoma often occurs in patients with AIDS (acquired immune deficiency syndrome). Kaposi's sarcoma, however, has different characteristics than typical soft-tissue sarcomas and is treated differently.

- In a very small fraction of cases, sarcoma may be related to a rare inherited genetic alteration of the p53 gene and is known as Li-Fraumeni syndrome. Certain other inherited diseases are associated with an increased risk of developing soft-tissue sarcomas. For example, people with neurofibromatosis type I (also called von Recklinghausen's disease, associated with alterations in the NF1 gene) are at an increased risk of developing soft-tissue sarcomas known as malignant peripheral nerve sheath tumors. Patients with inherited retinoblastoma have alterations in the RB1 gene, a tumor suppressor gene, and are likely to develop soft-tissue sarcomas as they mature into adulthood.

Cartilage tumors form in Cartilage tissue. They can be either benign (Chondroma) or malignant (chondrosarcoma). Frequently these tumors appear in bone, and not in pre-existing cartilage tissue. In some cases tumors that formed in other tissues may produce a cartilage-like matrix, an example of this is the pleomorphic adenoma of the sexual reproduction salivary glands.

Prognosis depends on the primary tumor grade (appearance under the microscope as judged by a pathologist), size, resectability (whether it can be completely removed surgically), and presence of metastases. The five-year survival is 80%.

Giant-cell fibroblastoma is a rare type of soft-tissue tumor marked by painless nodules in the dermis (the inner layer of the two main layers of tissue that make up the skin) and subcutaneous (beneath the skin) tissue. These tumors may come back after surgery, but they do not spread to other parts of the body. They occur mostly in boys and are related to dermatofibrosarcoma protuberans.

Soft-tissue sarcomas are relatively uncommon cancers. They account for less than 1% of all new cancer cases each year. This may be because cells in soft tissue, in contrast to tissues that more commonly give rise to malignancies, are not continuously dividing cells.

In 2006, about 9,500 new cases were diagnosed in the United States. Soft-tissue sarcomas are more commonly found in older patients (>50 years old) although in children and adolescents under age 20, certain histologies are common (rhabdomyosarcoma, synovial sarcoma).

Around 3,300 people were diagnosed with soft tissue sarcoma in the UK 2011.

Dysplasia (from Ancient Greek δυσ- "dys-", "bad" or "difficult" and πλάσις "plasis", "formation") is a term used in pathology to refer to an abnormality of development or an epithelial anomaly of growth and differentiation (epithelial dysplasia).

The terms hip dysplasia, fibrous dysplasia, and renal dysplasia refer to an abnormal development, at macroscopic or microscopical level.

Myelodysplastic syndromes, or dysplasia of blood-forming cells, show increased numbers of immature cells in the bone marrow, and a decrease in mature, functional cells in the blood.

Surgery, with as wide a margin of removal as possible, has generally been the most effective and preferred way to attack LMS. If surgical margins are narrow or not clear of tumor, however, or in some situations where tumor cells were left behind, chemotherapy or radiation has been shown to give a clear survival benefit. While LMS tends to be resistant to radiation and chemotherapy, each case is different and results can vary widely.

LMS of uterine origin do frequently, but not always respond to hormonal treatments.

Examples of dysplasia include epithelial dysplasia of the cervix (cervical intraepithelial neoplasia – a disorder commonly detected by an abnormal pap smear) consisting of an increased population of immature (basal-like) cells which are restricted to the mucosal surface, and have not invaded through the basement membrane to the deeper soft tissues. Analogous conditions include vaginal intraepithelial neoplasia and vulvar intraepithelial neoplasia. Metanephric dysplastic hematoma of the sacral region is a dysplastic overgrowth observed in infants.

Leiomyosarcoma, also referred to as LMS, is a malignant (cancerous) smooth muscle tumor. A benign tumor originating from the same tissue is termed leiomyoma. It is also important to note that while it has been believed that leiomyosarcomas do not arise from leiomyomas, there are leiomyoma variants for which classification is evolving.

About 1 person in 100,000 gets diagnosed with LMS each year. Leiomyosarcoma is one of the more common types of soft-tissue sarcoma, representing 10 percent to 20 percent of new cases. (Leiomyosarcoma of the bone is more rare.) Sarcoma is rare, consisting of only 1 percent of cancer cases in adults. Leiomyosarcomas can be very unpredictable. They can remain dormant for long periods of time and recur after years. It is a resistant cancer, meaning generally not very responsive to chemotherapy or radiation. The best outcomes occur when it can be removed surgically with wide margins early, while small and still in situ.

Clear cell sarcoma of the kidney (CCSK) is an extremely rare type of kidney cancer comprising 3% of all pediatric renal tumours. Clear cell sarcoma of the kidney can spread from the kidney to other organs, most commonly the bone, but also including the lungs, brain, and soft tissues of the body.

Despite the similarities in names, "clear cell sarcoma of the kidney" is unrelated to clear cell sarcoma of soft tissue, also known as malignant melanoma of soft parts.

2004 research showed that CCSK patients exhibit an improved relapse-free survival from a longer course of therapy when using vincristine, doxorubicin, and dactinomycin, but their long-term survival is unchanged compared with patients receiving 6 months of therapy.

Clear-cell sarcoma (formerly known as malignant melanoma of the soft parts) is a rare form of cancer called sarcoma. It is known to occur mainly in the soft tissues and dermis. Rare forms were thought to occur in the gastrointestinal tract before they were discovered to be different and redesignated as GNET.

Recurrence is common.

It has been associated with both EWSR1-ATF1 and EWSR1-CREB1 fusion transcripts.

Clear cell sarcoma of the soft tissues in adults is not related to the pediatric tumor known as clear cell sarcoma of the kidney.

PTEN hamartoma syndrome comprises four distinct hamartomatous disorders characterised by genetic mutations in the PTEN gene; Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome and Proteus-like syndrome. Although they all have distinct clinical features, the formation of hamartomas is present in all four syndromes. PTEN is a tumor suppressor gene that is involved in cellular signalling. Absent or dysfunctional PTEN protein allows cells to over-proliferate, causing hamartomas.

Cowden syndrome is an autosomal dominant genetic disorder characterised by multiple benign hamartomas (trichilemmomas and mucocutaneous papillomatous papules) as well as a predisposition for cancers of multiple organs including the breast and thyroid. Bannayan-Riley-Ruvalcaba syndrome is a congenital disorder characterised by hamartomatous intestinal polyposis, macrocephaly, lipomatosis, hemangiomatosis and glans penis macules. Proteus syndrome is characterised by nevi, asymmetric overgrowth of various body parts, adipose tissue dysregulation, cystadenomas, adenomas, vascular malformation.

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.