Mycotic aneurysm in an immunocompromised patient with pneumonia and spondylodiscitis: who’s guilty?

BACKGROUND: Mycotic aneurysm is a rare entity with rapid progression, which can be fatal without adequate treatment. The incidence of rupture is greater than that of degenerative aneurysms and is associated with a high mortality rate. CASE REPORT: We report the case of a 58-year-old man with a known history of HIV infection with good immunovirological staging, treated squamous cell carcinoma of the anal canal and chronic gastritis, who presented with a six-day history of intense back pain, malaise, fever, and chills. After examination, he was hospitalized with a clinical suspicion of acute pyelonephritis. During hospitalization, he was diagnosed with pneumonia of the right pulmonary base, infectious spondylodiscitis, and mycotic aneurysm of the abdominal aorta, which involved the visceral plaque. The microbiological workup revealed only positive blood cultures for Klebsiella pneumoniae. After a multidisciplinary discussion of the case and six weeks of antibiogram-oriented antibiotic therapy, the patient underwent an aorto-aortic interposition via left thoracophrenolaparotomy without the need to reimplant visceral vessels due to the patch configuration of the proximal anastomosis. The procedure was performed under left heart bypass. The postoperative course was uneventful, and the patient was discharged four weeks later. At 18 months follow-up, she remained asymptomatic and free of recurrence. CONCLUSION: In this case, it remains to be defined whether the cause of the mycotic aneurysm was hematogenous dissemination from the identified pneumonia or contiguity from the diagnosed spondylodiscitis. Given the morbidity and mortality associated with this entity, early diagnosis and adequate treatment with surgical correction and antibiotic therapy with sufficient duration and dose are important aspects for improving survival in these cases.