Abstract
Relevance: Stewart-Treves syndrome (STS) is a rare and extremely aggressive malignant vascular neoplasm, which is an angiosarcoma of the skin that develops against the background of long–term chronic lymphedema, more often in patients after radical treatment of breast cancer with lymph node dissection and radiation therapy. The disease is characterized by late diagnosis, rapid progression, and poor prognosis. The article presents a clinical case of Stewart–Treves syndrome in a patient with post-mastectomy lymphedema of the upper extremity, which developed more than 10 years after the combined treatment of breast cancer. The stages of clinical observation, diagnostic search, morphological and immunohistochemical verification of the diagnosis, and the features of antitumor treatment are described. The presented case highlights the need for long-term dynamic follow-up of patients with chronic lymphedema and high oncological alertness in relation to rare secondary malignant tumors.The study aimed to describe a clinical case of Stewart-Treves syndrome on the background of prolonged post-mastectomy lymphedema.Materials and methods: The description of the clinical case presents data from laboratory, instrumental, and physical research methods of a patient with primary multiple metachronous breast cancer and lymphangiosarcoma of the left forearm, who was examined, treated, and monitored at the State Clinical Hospital at the Multidisciplinary Medical Center of the Akimat of Astana (Kazakhstan).The patient was diagnosed with Primary multiple metachronous cancer. (C50.2) C-r of the left breast T2N0M0 II A st., nodular shape. The condition after a radical mastectomy by Madden on February 14, 2012, and radiation therapy in 2012. Clinical group 3 (C49.1) Lymphangiosarcoma of the skin of the left forearm, T4NxM0, stage IIIB. Stewart-Treves syndrome. The condition after an incision biopsy on December 19, 2024. The condition after 3 courses of self-administered GemTax chemotherapy. The patient continues self-administered GemTax chemotherapy.Results: During comprehensive diagnostics, angiosarcoma was morphologically and immunohistochemically verified. The patient received palliative chemotherapy, which resulted in temporary stabilization of her condition.Conclusion: The presented clinical case demonstrates the rare and aggressive nature of STS. This confirms the importance of timely morphological verification and a comprehensive interdisciplinary approach to the treatment of patients with chronic lymphedema.