A 26-year-old man without any past medical history presented with a sudden onset of severe right leg pain and six days of subjective fever. Though he was an avid soccer player, the patient denied any antecedent trauma and was able to bear weight on both legs despite the pain. He denied rash, nausea, vomiting, diarrhea, cough, hemoptysis, shortness of breath, and night sweats. He had a single, long-term female sexual partner and used barrier contraceptives intermittently. Having denied any known sexually transmitted infections, his medical history was pertinent only for treated latent tuberculosis prior to his emigration from Ghana 15 years before. Since then the patient had traveled back to Ghana one year and Mexico five months prior. He did not recall any gastrointestinal illness during travel or upon return. Vaccination history was not known. Family history included multiple first-degree relatives who died from sickle cell disease prior to his birth.
Upon presentation, the patient was febrile with maximal temperature 40.6  C, heart rate 95, respiratory rate 20 bpm, and blood pressure 132/82 mmHg. Physical examination was significant for marked tenderness on deep palpation over the right middle to distal anterior thigh. There was no outward signs of infection such as joint swelling, erythema, warmth, open wounds, induration, rash or decreased range of motion of the hips or knees. The patient was mildly leukopenic (WBC 4.5 K/mcl, normal 4.8-10.9), anemic (hemoglobin 11.9 g/dL, normal 13.5-17.5; hematocrit 34.3%, normal 41.0-53.0), with a normal platelet count. MCV was 77.6 fL/cell. He had elevated transaminase levels (AST 76 u/L and ALT 124 u/L), and mildly elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) of 13.40 mg/L and 58 mm/hour, respectively. An X-ray of the right lower extremity demonstrated a lucent lesion of the central mid to distal medullary space of the femur (Fig. 1), suspicious for an infarct or chronic osteomyelitis. MRI revealed a 24 cm cystic lesion centered in the diaphysis spanning down to the distal metaphysis, with internal complex fluid levels and thickened cortex surrounding the collection (Fig. 2), concerning for chronic osteomyelitis with abscess formation.
Aspiration of the femur on hospital day 2 revealed serosanguinous fluid, with Gram-negative rods visualized on Gram stain. The patient underwent an open biopsy and debridement on day 4; intraoperative findings included a relative decrease of marrow contents and a cystic cavity without purulence. Pathology showed acute on chronic osteomyelitis. Aspirate and open bone cultures grew Salmonella enterica, serovar Typhi, susceptible to levofloxacin, ceftriaxone, trimethoprim/sulfamethoxazole, and ampicillin/sulbactam. Blood cultures remained negative, as were AFB stains of the fluid, bone cultures, N. gonorrhea urine NAAT and HIV Ag/Ab.
Based on country of origin, family history of sickle cell disease, and Salmonella osteomyelitis, hemoglobin (Hb) electrophoresis was pursued. Results showed 62.8% HbA, 33.2% HbS, 3.7% HbA2 and 0.3% HbF, consistent with both sickle cell trait and likely thalassemia trait (due to HbS level <35%). Abdominal ultrasound showed normal splenic echotexture and dimensions (11 x 5 x 5.5 cm).
The patient received one week of ceftriaxone intravenously while inpatient, followed by ciprofloxacin 750 mg orally twice daily for a planned total 6-week course for Salmonella typhi chronic osteomyelitis. On day 10, CRP had decreased to 5.7 mg/L but ESR had increased to 102 mm/hr. Duration of antimicrobial course was extended to allow for follow up CT imaging, but this was not completed. Patient received approximately 8 weeks of antimicrobials in total. At last known follow up, patient had achieved clinical resolution of all prior symptoms. Given extent of involvement seen on initial imaging and surgery, further surgical intervention was suggested, but not pursued by patient due to lack of health insurance. Radiograph did confirm a healing bone lesion.