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GIANT SOLITARY CUTANEOUS ANGIOSARCOMA OF THE FOREARM OCCURRING OUTSIDE THE SETTING OF LYMPHEDEMA

Angiosarcoma (AS) is an aggressive vascular malignancy that can affect various anatomic sites. Although rare, cutaneous angiosarcoma (CAS) is the most common clinical manifestation of AS, accounting for approximately 50% to 60% of all AS. CAS is typically known to occur in three settings: (1) idiopathic, (2) following radiation treatment, or (3) is classically diagnosed following mastectomy with subsequent chronic lymphedema (known as Stewart Treves syndrome). We present a case of CAS on the forearm in a man with no history of lymphedema or radiation therapy, highlighting the necessity to discuss this diagnosis even outside the setting of conventional angiosarcomas.

Angiosarcoma (AS) is an aggressive vascular malignancy that can affect various anatomic sites. Although rare, cutaneous angiosarcoma (CAS) is the most common clinical manifestation of AS, accounting for approximately 50% to 60% of all AS. CAS is typically known to occur in three settings: (1) idiopathic, (2) following radiation treatment, or (3) is classically diagnosed following mastectomy with subsequent chronic lymphedema (known as Stewart Treves syndrome). We present a case of CAS on the forearm in a man with no history of lymphedema or radiation therapy, highlighting the necessity to discuss this diagnosis even outside the setting of conventional angiosarcomas.

Introduction:-
Cutaneous angiosarcoma (CAS) is a rare malignant vascular tumor located in 96% of the cases on the head and neck.They typically occur following chronic lymphedema or radiation treatment [1]. We present a case of CAS on the forearm in a man without lymphedema or any other risk factor for angiosarcoma.

Case Report:
A 54-year-old man with no medical history presented to the dermatology office after he developed, over the preceding year, a painful violaceous nodule on his left forearm. The lesion was initiallymistaken for a bruise, leading to a delayed presentation. The nodule later progressed to a 12x14 cm tumor with significant infiltration and fixation to the underlying structures, with overlying hemorrhagic-necrotic crust andbloodstained discharge ( Figure  1). The physical exam did not objectify lymphedema. No satellite or distant lesions were noted. Sensation and motor function were intact.
The histologic analysis revealed a proliferation of irregular vascular clefts, separated by collagen fibers, with considerable cell atypia, prominent towards the lumen; the lesion exhibited cohesive epithelioid masses of atypical, large, rounded cells with eosinophilic cytoplasm and high indexed mitotic figures in the dermis. The cells stained positive for CD34 and ki-67, consistent with CAS (Figure 2, 3). Computed tomography did not show lymph node or distant metastases. The TNM staging system for soft tissue sarcoma of the trunk and extremities was IIIB. A wide excision of the tumor was performed and revealed positive margins imposing further excision. Additional treatment options were explained to the family, including radiation therapy, chemotherapy or amputation. Thepatient and his family chose the latter option. After the procedure, he was subsequently lost to follow-up.

Discussion:-
The CAS occurs preferably on the scalp and face, and when it is localised on the upper extremities it is usually in the context of lymphedema [1]. Only few caseswere reported on the extremities without prior predisposing factors [2-4] ( Table 1). To our knowledge, this is the first report of CAS occurring on the upper limb without preceding lymphedema. Suchak published a serie of thirtheenidiopathic cases of CAS on the extremities; none was located on the upper limbs [4] Clinical and histological diagnosis of sporadic CAS is challenging. The CD31 is until now the only best immunohistochemical marker with a high sensitivity and specificity.
There have been a few reports of CAS on the extremities treated with amputation without signs of recidive or metastasis [4,5]. Our patient was lost to follow-up and this contingency could not be verified.
In conclusion, we presented this case to highlight the rare occurrence of CAS in a patient outside the setting of conventional lymphedema or radiation on the upper extremity, highlighting the necessity to discuss this diagnosis even outside theconventional setting of angiosarcomas as timely recognition is necessary for further management and immediate treatment in order to optimize survival.