Keratitis caused by an unusual fungus, Phoma species

Purpose. To describe the histopathologic profile of a case of keratitis caused by Phoma species and to evaluate the role of polymerase chain reaction in the diagnosis of this unusual fungal infection. Methods. Clinical information was extracted after a review of the medical records of a 72-year-old man developing a nonhealing corneal ulcer with brownish pigmentation. Microbiologic cultures and histopathologic examination were performed on the keratectomy specimen. Polymerase chain reaction was performed on DNA extracted from five (10-μm thick) paraffin-embedded sections using panfungal primers. Results. Histopathologic examination revealed round spherules of variable diameter (5-30 μm) admixed with septate hyphae at the edges of the perforated cornea. Microbiologic cultures grew a fungus identified as Phoma species. Polymerase chain reaction from the specimen yielded a single product with an approximate size of 360 bp. Conclusion. Phoma species, though rarely pathogenic to humans, may cause keratitis in some patients. To our knowledge, this is the first well-documented case of Phoma keratitis.