LAUSR

Talimogene laherparepvec (TVEC) is a genetically modified herpes simplex virus‐1 approved as an intralesional oncolytic immunotherapy for the treatment of advanced melanoma. Cutaneous reactions at the site of injection may mimic recurrent or progressive melanoma; histopathological findings have included chronic granulomatous dermatitis, neutrophilic dermatitis, lymphocytic dermatitis, and pigment incontinence. We report a 39‐year‐old male with metastatic stage IIIc melanoma treated with TVEC with clinical regression of melanoma lesions that later developed pink nodules at sites of prior injection. Histopathology demonstrated a nodular mononuclear infiltrate that stained strongly and diffusely with CD45 and CD20 with a surrounding rim of CD3‐positive T‐cells. Immunoglobulin gene rearrangement was negative for a clonal B‐cell population. To our knowledge, this is the first report of a pseudolymphomatous reaction mimicking recurrent melanoma after TVEC therapy.