Corynebacterium accolens is a rare human pathogen. We encountered a case of C. accolens isolated from a thigh collection in a man with osteomyelitis of the adjacent pubic symphysis. CASE REPORTA previously healthy 69-year-old man presented to the Emergency Department with a 3-week history of an increasingly painful left hip. He had a history of having fallen when lifting furniture 3 months previously and had been treated with simple analgesics. Due to increasing pain, his general practitioner organized a pelvic X-ray 4 days prior to his hospital presentation. This showed a fracture involving the left pubic ramus. Since his pain was not controlled, he was referred to hospital for further management. He denied any fever or night sweats, and there had been no significant weight loss. He had a recent excision of basal cell carcinoma in the left preauricular region approximately a month previously and had had a partial left knee joint replacement in the past. Clinical examination was unremarkable, apart from tenderness around the pubic symphysis. His inflammatory markers were raised with C-reactive protein (CRP) of 288 mg/liter (normal value of Ͻ5) and erythrocyte sedimentation rate (ESR) of 23 mm/h (normal value of Ͻ20). His white cell count and differentials were normal. A magnetic resonant imaging (MRI) scan showed insufficiency fractures of the left symphysis pubis and right sacral alar, with probable osteomyelitis of the left symphysis pubis, myositis, and a soft tissue collection within the left adductor brevis muscle measuring approximately 40 by 19 by 18 mm. An aspirate of this collection was performed under ultrasound guidance and was sent for cytology and microbiological analysis. He was given the provisional diagnosis of osteomyelitis and was started on empirical intravenous flucloxacillin. The cytology report showed numerous neutrophils, some macrophages, and nonspecific birefringent particles, but no malignant cells. He was discharged on the 10th day of admission on home intravenous treatment with cephazolin for 4 weeks. This was followed by 4 weeks of oral amoxicillin. He showed clinical improvement, with CRP and ESR declining to 6 and 9, respectively, over a period of 3 weeks.Gram staining of the aspirate from the adductor brevis collection revealed numerous leukocytes with occasional Grampositive coccobacilli seen both intracellularly and extracellularly. The aspirate was received in a sterile, screw-top bottle and was plated onto Columbia sheep blood agar, chocolate agar, MacConkey agar, and blood neomycin agar and incubated aerobically and anaerobically. After 48 h of incubation, small, nonhemolytic, gray-white pinpoint colonies were seen on the sheep blood agar. The isolate was recovered in pure culture. The colonies were slow growing, but their growth was enhanced by Tween 80 on repeat culture. One drop of Tween 80 was instilled onto a lawn of C. accolens on sheep blood agar. After overnight incubation, colonies covered by Tween 80 showed significantly enhanced growth compared to areas without it....