Stewart Treves syndrome as a catastrophic sequela of chronic lymphedema: Clinical spectrum, management challenges, and outcomes.

Objective: Stewart Treves syndrome (STS) is a rare, aggressive lymphangiosarcoma arising in chronically lymphedematous tissue, most often after mastectomy with axillary lymph node dissection, and occasionally in lower limb lymphedema. We aimed to describe the clinical spectrum, diagnostic challenges, management, and outcomes of upper and lower limb STS, highlighting the importance of early recognition in improving survival. Methods: We conducted a retrospective review of three patients diagnosed with STS between 2020 and 2025 at our tertiary vascular surgery center specializing in lymphedema. Clinical presentation, imaging, histopathology, management strategies, and postoperative outcomes were analyzed. Results: Two female patients developed upper limb STS after breast cancer surgery and radiotherapy, and one male patient developed lower limb STS postcystectomy and pelvic radiotherapy. All presented with violaceous or nodular lesions on chronically lymphedematous limbs, initially misdiagnosed as cellulitis or ecchymosis. Biopsy confirmed angiosarcoma (CD31/CD34 positive). Two patients underwent radical limb disarticulation; one achieved 2-year recurrence-free survival with adjuvant therapy, and the other remained disease-free at 6 months. The third patient, who declined early biopsy, developed rapid pulmonary metastases and died within months. Conclusions: STS should be suspected in any patient with chronic lymphedema who develops new violaceous, nodular, or ulcerative lesions, particularly in the proximal segments. Prompt biopsy and radical surgical excision remain essential, although the overall prognosis is poor. Prevention through effective lymphedema management, clinician vigilance, and long-term follow-up is critical to decrease this devastating complication.