Lactococcus lactis cremoris infection: not rare anymore?

A middle-aged female patient with diabetes was admitted with a right neck abscess. Ultrasound scan revealed a necrotic abscess suspicious of malignancy and biopsy showed evidence of chronic inflammation. In order to isolate the primary source of malignancy, we performed MRI and positron emission tomography scans but neither had conclusive results. Subsequently, we performed an incision and drainage of the mass in order to alleviate pressure symptoms. The ensuing histological examination revealed that the mass was caused by Lactococcus lactis cremoris. As such, the patient was treated with antibiotics and made a complete recovery. This report reinforces the scarce existing evidence that L lactis cremoris is a potential pathogen in adults. The case shows that atypical organisms should always be considered in the working diagnosis of an atypical neck abscess especially due to the rise in popularity of organic farming.