Lawsonella clevelandensis as the causative agent of a breast abscess

Lawsonella clevelandensis is a Gram-stain-positive, partially acid-fast, anaerobic, being considered a new species within a new genus in the suborder Corynebacterineae. There are only a few cases reported worldwide. This is a fastidious microorganism, difficult to identify by conventional methods, leading to inappropriate treatments. The authors report a case of a 29-year-old woman with a 3-week evolution of a breast nodule. There was a family history of breast carcinoma. Samples were collected for histological and microbiological examination. Gram staining revealed Gram-positive filamentous bacilli, acid-fast-positive. The cultural examination revealed a Lawsonella clevelandensis that was confirmed by molecular methods. At the last follow up, the evolution was favorable; the abscess was resolved, with no evidence of recurrence. To our knowledge the present case was the first reported in Europe.