Stewart–Treves syndrome refers to a lymphangiosarcoma, a rare disorder marked by the presence of an angiosarcoma (a malignant tumor of blood or lymph vessels) in a person with chronic (long-term) lymphedema.
[1] Stewart-Treves syndrome lesions often present as several reddish blue macules or nodules that may develop polypoid.
[1] As the angiosarcoma grows and spreads, the overlying atrophic epidermis may ulcerate, resulting in repeated episodes of bleeding and infection.
Other hypotheses include a malignant transformation caused by lymphatic drainage blockage and decreased antigen presentation, resulting in cancer evading immune monitoring at an "immunologically privileged site.
[6] Despite the fact that Stewart-Treves syndrome is also known as lymphangiosarcoma, ultrastructural and immunohistologic investigations demonstrate that this cancer is caused by blood arteries rather than lymphatic vessels.
The immunohistologic and ultrastructural results listed below can be utilized to confirm that the tumor is derived from blood vessels:[1] Magnetic resonance imaging is recommended to assess the local extent of angiosarcomas.
In patients with chronic lymphedema, fluorodeoxyglucose (FDG) PET/CT scanning may show tumor spread, including metastases, and detect probable malignant change.
Fred Stewart and Norman Treves reported a case series detailing six patients with lymphangiosarcoma who had chronic lymphedema following a mastectomy.