Salmonella‐related mycotic aortic aneurysm heralding a diagnosis of multiple myeloma
Authors: Javier Munoz, Susie Namo, Michael Stoltenberg, Robert Chapman
Journal: American Journal of Hematology (2012)

Plasma cell dyscrasias constitute a spectrum of diseases that may present as a single lesion (solitary plasmacytoma) or a more systemic process [multiple myeloma (MM)]. We present a rare case of solitary plasmacytoma of the bone (SPB) that was found to have progressed to MM shortly after a diagnosis of salmonellosis. An 85-year-old male with multiple medical conditions presented with fever and diarrhea. Comorbidities included chronic kidney disease and SPB of the third lumbar vertebrae (panel A) which was diagnosed 2 years ago via needle biopsy of the lumbar lesion (panel D) with subsequent negative work-up for overt MM hence the patient was treated with external beam radiotherapy and vertebroplasty. Upon admission, blood cultures were positive for nontyphoidal salmonella thus the patient received intravenous ceftriaxone for 14 days. Shortly afterward, restaging magnetic resonance imaging of the spine showed multiple new lytic lesions (panel B) compared with his baseline skeletal bone survey. Incidentally, imaging revealed a large abdominal aortic aneurysm (panel C) measuring 7.5 × 4.9 cm adjacent to one of the vertebral lytic lesions. Serum protein electrophoresis remained negative for monoclonal proteins although his serum kappa free light chains rose to 13,900 mg/mL. Bone marrow biopsy showed 12% plasma cells (panel E) confirming a diagnosis of symptomatic MM Durie-Salmon stage IIIB. Surgery evaluated the patient regarding his aortic aneurysm and felt that the patient was not a candidate for surgical resection due to his multiple medical comorbidities and active infection. The patient's performance status declined rapidly and the patient decided for hospice instead of bortezomib-based palliative chemotherapy Image 1.. Panel A. Computed tomography showing solitary plasmacytoma of the third lumbar vertebrae. Panel B. Magnetic resonance imaging of the spine showing multiple lytic lesions. Panel C. Computed tomography revealing a large abdominal aortic aneurysm measuring 7.5 × 4.9 cm adjacent to one of the vertebral lytic lesions. Panel D. Pathologic findings obtained by needle biopsy of the lumbar lesion showing solitary plasmacytoma of the third lumbar vertebrae. Panel E. Bone marrow biopsy showing 12% plasma cells confirming a diagnosis of symptomatic multiple myeloma. Predisposing risk factors for the acquisition of nontyphoidal salmonella bacteremia include extremes of age and immunosuppression such as malignancies. Salmonella bacteremia may be complicated by mycotic aneurysm formation with subsequent fatal outcome if surgery is not implemented [1]. Optimal treatment implies prompt surgical debridement, and prolonged antibiotic therapy. Retrospective studies point to nontyphoid Salmonella as the most common responsible microorganism of infected aortic aneurysms [1]. Progression to MM should be considered when facing uncommon infections in patients previously thought to have a more localized form of plasma cell dyscrasia. Timely diagnosis is critical as untreated MM has a high propensity to cause irreversible organ damage. Several cases of salmonellosis have been reported in patients with MM [2-4], nevertheless in our patient, salmonella bacteremia and mycotic aortic aneurysm heralded a new diagnosis of MM.