Acrometastasis of the Third Finger in Widespread Radiation‐Induced Angiosarcoma

An 88-year-old woman with dementia, who previously underwent tumorectomy and radiation for left breast cancer in 2007, developed extensive ulcerated purplish nodular lesions of the left breast (Figure 1A) 5 years later. These lesions were identified as angiosarcoma located in the radiotherapy field. Despite receiving four courses of palliative chemotherapy with taxol, she experienced painful swelling in the third phalanx of her left middle finger, initially treated with rifampicin and ofloxacin for 3 weeks. Distal purplish nodular cutaneous lesions (Figure 1B) and radiological evidence of erosion and destruction of the distal phalanx (Figure 1C) persisted. A biopsy confirmed the presence of angiosarcoma acrometastasis, and the patient was provided with best supportive care but passed away 1 month later. Acrometastases of the hand are exceptionally rare, comprising less than 0.1% of malignant bone lesions and up to 0.6% in autopsy series [1]. These lesions primarily occur in patients around 60 years of age, often with a history of lung carcinoma, and they carry a poor prognosis, typically averaging around 6 months [2]. In the hand, both metacarpals and phalanges can be affected, with the distal phalanx of the thumb being most commonly involved [3]. These lesions can mimic inflammatory or benign conditions, such as gout or infections, which may lead to misdiagnosis, underreporting, and delayed treatment. Additionally, some patients might overlook their condition due to denial, addiction, or cognitive impairment, resulting in presentation at advanced stages with widespread disease and a poor prognosis, as seen in the patient. There are several other complications that can occur after chemotherapy or radiotherapy for breast cancer, including localized pain or skin lesions [4], breast lymphedema [5], radiation-induced fibrosis of the breast [6], skeletal muscle dysfunction [7], osteoporosis [8], neuropathic pain [9], valvular heart disease [10] or cardiovascular toxicity [11], amenorrhea and infertility in younger women [12], metabolic alterations [13] or diabetes and cancer-related fatigue [14], cognitive impairment [15] with or without sleep disturbance [16], anxiety or depression [17], radiation-induced pulmonary fibrosis [18] or bronchiolitis obliterans with organizing pneumonia [19], and second malignancies such as leukemia [20]. Radiation-induced angiosarcoma of the breast is a very rare and severe complication of radiotherapy, primarily observed in older women, with an estimated incidence of 0.05%–0.3% [21]. The aggressive nature of this tumor and its propensity for metastasis, although unlikely to the finger, might be attributed to dysregulation of angiogenesis combined with chronic lymphedema, which could facilitate the dissemination of neoplastic cells [22]. E.R. and P.G. were responsible for conceptualization, methodology, writing – original draft, writing – review and editing, supervision, and project administration. The authors acknowledge the patient's family who gave written consent to publish the case. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.