Lobular panniculitis after subcutaneous administration of interleukin-2 (IL-2), and its exacerbation during intravenous therapy with IL-2

Interleukin-2 (IL-2) is now registered for the treatment of renal cell carcinoma in a number of European countries. The subcutaneous (sc) route of administration is being used increasingly because of its better toxicity profile compared with higher dose intravenous (iv) protocols. We report here a patient who developed a lobular panniculitis at the site of sc IL-2 injection which prevents continuation of sc therapy. Subsequent administration of the same IL-2 dose by iv injection caused recurrence of the problem again necessitating discontinuation of IL-2 treatment.