Case Presentation: 57 years old lady with hypertension presented to ER with chest and neck pain for 1 week. Pain was in upper right side of chest and collar bone. Pain character was sharp, 9/10 in intensity, not relieved by acetaminophen, aggravated with movement and without associating factors. On exam, vital signs were normal. She had swelling, erythema and tenderness over manubrium. Laboratory data revealed WBC of 13.7 without bands, C-reactive protein (CRP) of 63 and normal sedimentation rate (ESR). CT scan with contrast was obtained, which revealed osteitis of the manubrium with surrounding soft tissue density, representing inflammation or condition of sclerosis and hyperostosis. MRI showed acute on chronic sterno-manubrial osteomyelitis (OM). Patient was subsequently treated in the hospital with intravenous(IV) Vancomycin and cefepime for OM. Biopsy of manubrium on day 2 of hospitalisation did not reveal findings of acute osteomyelitis. Staining and culture of the sample were negative. Patient was discharged on IV Vancomycin and ceftriaxone for 6 weeks. Despite antibiotics, patient continued to have pain and developed acute kidney injury with supra-therapeutic vancomycin level while taking ibuprofen. She returned to hospital 3 weeks later. Given failure to respond to antibiotics and negative biopsy results, a diagnosis of sternocostoclavicular hyperostosis (SCCH) was made. Bone scintigraphy scan revealed increased uptake throughout manubrium. Antibiotics were stopped, and patient was discharged on prednisone. Outpatient visit 2 weeks later revealed resolution of her symptoms.
Discussion: SCCH is a rare disorder with no well-defined incidence. This case highlights the challenges encountered in its diagnosis. It is often confused with the diagnosis of OM given their similarity. However, the unusual presence of OM in sternocostoclavicular region without prior history of trauma or surgery should raise the suspicion of SCCH. Our patient did not have prior history of surgery or trauma to chest. Patient did not have acne or pustulotic skin lesions on her palms, seen in SAPHO syndrome (synvotis, acne, pustulosis, hyperostosis, osteitis) with which SCCH is associated. There are no laboratory tests to diagnose SCCH and the value of serologic testing is to exclude other causes of inflammation. ESR and CRP levels do not correlate with disease activity. Paget’s disease is another condition which is difficult to differentiate from SCCH. Paget’s disease involves axial skeleton accompanied by elevated alkaline phosphatase which was not seen in our patient. SCCH is a diagnosis of exclusion and a complete workup to exclude other causes of inflammation is recommended. Therefore, patient received bone scan which showed increased uptake only in manubrium excluding the possibility of seronegative spondyloarthropathies which cause increase uptake in sacroiliac joints. Our patient was not positive for HLA B27 either. Since she did not improve with antibiotics, a diagnosis of SCCH was made. Her outpatient clinical course showed relapsing remitting pattern. She was later started on methotrexate by her rheumatologist to avoid side effects of prednisone.
Conclusions: Differentials should be broadened to include SCCH in patients with sternal inflammation who do not have prior history of trauma or surgery. Patients should have close outpatient visit after hospital discharge for prompt diagnosis of SCCH and to avoid futile use of antibiotics and their side effects.
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