Synovial sarcomas occur in adolescents and young adults, especially males, have no racial predilection, and are not noted for familial occurrence. The Tumours have been shown to have X:18 chromosomal translocations t(X:18) (p11.2; q11.2), involving a breakpoint at Xp11.2, resulting in the formation of a hybrid transcript (Gilgenkrantz et al. 1989; de Leeuw et al. 1995; Carbano et al. 2002; de Leeuw et al. 1994).
A study of the family histories of children with soft tissue sarcomas showed an increased family history of the Li–Fraumeni syndrome, sarcomas, gastric cancer, and neurofibromatosis, and it was considered that one-third of cases had a genetic susceptibility (Hartley et al. 1993).
Extraskeletal myxoid chondrosarcomas have been found to show a 9:22 chromosomal translocation: t(9; 22)(q31; q12.2) causing a NR4A3/TFG fusion gene (Hisaoka et al. 2004).
Kaposi sarcoma (multiple idiopathic pigmented hemangiosarcoma) has rarely been described in several members of the same family, suggesting an autosomal dominant pattern of inheritance. The condition is characterized by red–purple nodules, plaques, and macules which are commonest on the extremities but can occur at any site, including internally. Edema is associated, due to Tumours infiltration of lymphatics, and the lesions spread, often with metastatic dissemination, usually with fatal results, although spontaneous regression has been described. The condition is commoner in people of Italian or Jewish origin (DiGiovanna and Safai 1981). Kaposi sarcoma is usually sporadic and immunosuppressed transplant recipients; it is the most common neoplasm affecting patients with AIDS, and HIV infection is an important risk factor in its development: the KS risk of AIDS patients is 20,000-fold over that of the general population. Foster et al. (2000) found a strong association between the IL6 gene promoter polymorphism and susceptibility to Kaposi sarcoma in HIV-infected men. Homozygotes for IL6 allele G, associated with increased IL6 production, were overrepresented among patients with Kaposi sarcoma, whereas allele C homozygotes were underrepresented. A novel herpes virus, termed KS-associated herpes virus (KSHV) or human herpes virus 8 (HHV8), has been detected in Kaposi sarcoma tissues, indicating that a viral infection may be important in the etiology of this condition (Kedes et al. 1996).
Uterine leiomyomas (fibroids) occur in individuals with leiomyomatosis, where germline mutations in the fumarate hydratase (FH) gene predispose to these Tumours and to type 2 papillary renal cell cancer.