osteomyelitis; However, because of her body habitus, the injection overpenetrated the deltoid resulting in osteomyelitis of the humerus.; This literature marketed report was received from the authors of a published literature article, referring to a 15-year-old female patient. The patient's medical history, concurrent condition and concomitant therapy were not reported.  On day 1 (reported as January 16 in unknown year), the patient was vaccinated with the third dose of Quadrivalent Human Papillomavirus (Types 6,11,16,18) Recomb. Vaccine (manufacturer unknown) (strength, dose, frequency, lot# and expiration date were unknown) intramuscularly for prophylaxis on left arm.  On an unknown date, the patient reported development of severe pain in her arm and tingling in her fingers seconds after receiving the injection. The pain persisted, and on day 12 she was seen as an outpatient by an orthopedic surgeon. The magnetic resonance imaging (MRI) showed focal edema involving the deltoid muscle thought to be related to injection site. Fluid and edema tracking along the posterolateral aspect of the proximal humeral diaphysis with mild associated periostitis, negative for osteomyelitis or drainable fluid collection. The complete blood count at that time was reported as normal. No new intervention was made. On day 26 (reported as February 10 in unknown year), the patient continued to report persistent pain (10 out of 10 pain score) that was markedly limiting her daily function. She returned to the orthopedist and was diagnosed with frozen shoulder. Her shoulder was injected at the glenohumeral joint with a steroid, the product and the dose were not reported, and a 5-day course of prednisone was prescribed. The steroids did not provide pain relief or improve range of motion of the left arm. The patient sought treatment by a neurologist for persistently worsening pain on day 29 (reported as February 13 in unknown year). The diagnosis of Parsonage-Turner syndrome was made and gabapentin 400 mg by mouth 3 times daily was initiated. The pain intensified to an unbearable level, and mobility did not improve compelling the patient to seek help from a second neurologist on day 31 (reported as February 15 in unknown year). A second MRI of the cervical spine was ordered and reported as normal. On day 35 (reported as February 19 in unknown year), the pain had not relented and was still unbearable, persistent, and not responding to any of the previous treatments.   In the emergency department (ED), the patient's physical examination was positive for tenderness and swelling over the left deltoid and considerable pain with range of motion. A neurologic examination of the left arm recorded strength 4/5 (unknown unit) with finger grasp, 1/5 (unknown unit) for deltoid muscle, and 2/5 (unknown unit) for bicep. A complete blood count reported a white blood cell (WBC) count 11.6*10^9 cells per liter, c-reactive protein (CRP) was less than 0.4 mg/dL, and erythrocyte sedimentation rate (ESR) was 32 mm/h. A third MRI of the brachial plexus revealed osteomyelitis of the left proximal humeral diametaphysis with associated periosteal elevation, adjacent suppurative phlegmon formation, and myofasciitis involving the deltoid and triceps musculature. An x-ray of the left humerus was read as periosteal new bone formation along the posterolateral left proximal humeral metadiphysis, with adjacent stippled density probably reflecting heterotrophic bone formation in the setting of prior soft tissue trauma. The patient was admitted to the general pediatric ward for pain control and further management of the osteomyelitis.  On day 36 (reported as February 20 in unknown year), the patient was taken to the operating room for an incision and drainage of the abscess, bone biopsy, and wound cultures. Antibiotics were initiated after the procedure with cefazolin 2000 mg intravenously every 8 hours as per the hospital empirical antibiotic guidelines for pediatric patients. By day 38, on physical examination, the patient had improved her ability to lift her arm and could fully bend at the elbow without discomfort. The pediatric infectious disease physician recommended changing cefazolin to cephalexin 1000 mg by mouth every 6 hours for 11 days followed by cephalexin 1000 mg by mouth every 8 hours for 4 weeks to complete 6 weeks of antibiotic treatment for osteomyelitis. The left proximal humerus intramedullary bone biopsy revealed findings suggestive of acute osteomyelitis with a low degree of acute inflammation. The final report of all cultures and gram stains taken during hospitalization was negative for growth or isolation of microorganisms. The patient was discharged on day 40 (reported as February 24 in unknown year) and had a full recovery of left arm function several months after completing the follow-up therapy. The injury was attributed to overpenetration by the needle during the intramuscular injection she had received in the previous month.  The reporter considered the event was related to Quadrivalent Human Papillomavirus (Types 6,11,16,18) Recomb. Vaccine (manufacturer unknown).  Upon internal review, the event of osteomyelitis was determined to be medically significant.   Literature report:  A copy of the published article is attached as further documentation of the patient's experience.