Listeria monocytogenes endophthalmitis with a black hypopyon

A 68-year-old woman had a marked decrease in visual acuity, increased intraocular pressure, and acute iridocyclitis. She developed a pigmented hypopyon simulating an occult intraocular melanoma. Two anterior chamber paracenteses showed growth of Listeria monocytogenes. The patient received systemic intravenous penicillin, topical fortified gentamicin sulfate drops, and intraocular injections of cephaloridine. On discharge from the hospital after a two-week stay, visual acuity had improved and intraocular pressure had decreased.