Pembrolizumab as an Off-Label Treatment of Facial Angiosarcoma: A Case Report

of Case: We report an atypical case of cutaneous angiosarcoma presenting as unilateral nasal swelling in an elderly male. The lesion was unresponsive to topical and antibiotic therapy. Diagnosis was confirmed after surgical excision, and disease control was ultimately achieved through radiation and off-label use of pembrolizumab. Patient Info: A 79-year-old male with a history of squamous cell carcinoma presented with a 1–2 month history of erythematous, scaly swelling of the left nasal tip and ala. Family history was notable for nonmelanoma skin cancer.

Initial differential diagnoses included contact dermatitis, rosacea, and rhinophyma. A shave biopsy revealed actinic damage but no malignancy. Following persistent symptoms and referral to plastic surgery, debulking surgery was performed. Histopathology confirmed cutaneous angiosarcoma.

The patient declined wide local excision and instead underwent a 4-week course of hypofractionated radiation. Subsequent imaging showed regional lymph node recurrence. He declined biopsy and surgery, and was started on off-label pembrolizumab immunotherapy for disease control.

Following immunotherapy, the patient experienced sustained remission with no clinical or radiographic evidence of disease four years post-treatment.

Cutaneous angiosarcoma is a rare, aggressive malignancy with a poor prognosis. This case illustrates the importance of considering angiosarcoma in atypical facial lesions and demonstrates disease control using a non-traditional, patient-centered treatment strategy. Immunotherapy with pembrolizumab may offer a promising option in select patients, particularly those with contraindications to extensive surgery.