Abstract

Olaparib is an oral poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor that was first FDA-approved for the treatment of BRCA-mutated advanced ovarian cancer. Over the past several years, olaparib has been approved to treat certain types of metastatic breast cancer, metastatic pancreatic cancer, and metastatic prostate cancer. Due to its expanding use, identification of cutaneous adverse events secondary to olaparib is essential. We present a rare case of small to medium vessel vasculitis in the setting of olaparib therapy. Our patient is a 53-year-old female with left breast stage IIIB invasive ductal carcinoma in the setting of a germline BRCA2 mutation who had failed several lines of treatment. Approximately seven days after starting olaparib, she developed a painful, non-pruritic eruption on the bilateral legs. Clinical examination was notable for erythematous to hyperpigmented papules and non-indurated retiform plaques involving the bilateral lower extremities. One punch biopsy of the left lower leg demonstrated perivascular and periadnexal infiltrate consisting of lymphocytes and neutrophils in the dermis. Small and medium vessels in the deep dermis displayed fibrinoid degeneration of the vessel walls with associated nuclear dust and extravasated erythrocytes. Laboratory monitoring revealed a mildly elevated creatinine and a normal urinalysis, with further studies pending. To our knowledge, vasculitis secondary to olaparib has only been reported once previously, and that case demonstrated only medium-vessel involvement. Additional cases are necessary to understand the pathogenesis and clinical course of this cutaneous adverse event.

Financial Disclosure: No current or relevant financial relationships exist.