Syphilitic vasculitis: Diagnostic challenge

Abstract

the absence of an infectious focus, normal cervical and dorsal column X-ray, a thoracic abdominal and pelvic CT scan was done which revealed a collection at the left psoas muscle level, as well as other infectious lesions of bronchogenic dissemination versus septic embolus. Transthoracic echocardiogram excluded infectious endocarditis. Due to elevated sedimentation rate (91 mm), normocytic normochromic anemia (Hb 8.7 g/dL, VGM 76 fL), and monoclonal IgG protein spike on protein electrophoresis, a bone biopsy was performed and confirmed multiple myeloma (IgG k). Blood cultures were positive for MRSA. Results: She completed 21 days of Vancomycin, became apyretic, blood cultures were negative and abdominal CT scan control showed resolution of the abscess and of the pulmonary lesions. The patient was sent for hematology–oncology follow-up but declined chemotherapy for multiple myeloma. Conclusions: The primary psoas abscess is a rare entity, with challenging diagnosis and therapy. This is an unusual presentation because of the patient's age and the absence of clinical symptoms. The coexistence of an immunocompromised state, the multiple myeloma, favored the abscess formation. Systemic antibiotherapy was effective in the complete resolution of the lesion.