Infective Native Aortic Aneurysm: a Delphi Consensus Document on Treatment, Follow Up, and Definition of Cure.

OBJECTIVE: Evidence is lacking to guide the management of infective native aortic aneurysm (INAA). The aim of this study was to establish expert consensus on surgical and antimicrobial treatment and follow up, and to define when an INAA is considered cured. METHODS: Delphi methodology was used. The principal investigators invited 47 international experts (specialists in infectious diseases, radiology, nuclear medicine, and vascular and cardiothoracic surgery) via email. Four Delphi rounds were performed, three weeks each, using an online questionnaire with initially 28 statements. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements were revised and added or deleted, and the results were presented in the iterative rounds. Consensus was defined as ≥ 75% of the panel rating a statement as strongly agree or agree on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha > 0.80. RESULTS: All 49 panellists completed all four rounds, resulting in 100% participation. One statement was added based on the results and comments of the panel, resulting in 29 final statements: three on need for consensus, 20 on treatment, five on follow up, and one on definition of cure. All 29 statements reached agreement of ≥ 86%. Cronbach's alpha increased for each consecutive round; round 1, 0.85; round 2, 0.90; round 3, 0.91; and round 4, 0.94. Thus, consensus was reached for all statements. CONCLUSION: INAAs are rare, and high level evidence to guide optimal management is lacking. This consensus document was established with the aim of helping clinicians manage these challenging patients, as a supplement to current guidelines. The presented consensus will need future amendments in accordance with newly acquired knowledge.

Emphysematous Salmonella-Infected Aneurysm of the Aortic Arch: Case Report.

BACKGROUND: Infected aortic aneurysm is a relatively rare disease with significant morbidity and mortality. Because of its deeper position, patients with infected aortic arch aneurysms may present with only fever and other vague symptoms, such as weakness, fatigue, dizziness, anorexia, and functional decline. It is difficult confirm a diagnosis that is based solely on history or physical examination, and it may only be apparent on imaging studies. CASE REPORT: We present a brief case report of a patient presenting to the emergency department with unexplained fever who was diagnosed with emphysematous salmonella-infected aneurysm of the aortic arch. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Infected aortic arch aneurysm is an extremely unusual disease entity that emergency physicians encounter. Because of the high mortality and morbidity of this catastrophic disease, an infected aortic aneurysm should be considered as a possible diagnosis in patients with persistent fever and vague symptoms without a specific infection focus. To avoid delayed diagnosis, emergency physicians should be aware of infected aortic arch aneurysm.

Treatment of superior mesenteric artery mycotic aneurysm by synthetic vascular graft: A case report.

Superior mesenteric artery (SMA) aneurysm is a rare disease, especially if it is mycotic (infective) in origin. It is difficult to detect the problem during its initial natural course and usually presents in late phase due to its complications such as rupture, dissection, haemorrhage, and mesenteric ischaemia. Initially, the patient present with non-specific symptoms like vague colicky abdominal pain, nausea, vomiting, discomfort, malaise, and low-grade fever but prompt workup and intervention can lead to definitive diagnosis and uneventful outcome. This report describes the case of a 60-year-old male patient who presented with non-specific abdominal symptoms and, on workup, was diagnosed with superior mesenteric artery mycotic aneurysm. It was successfully treated surgically by resection of aneurysm and reconstruction of superior mesenteric artery by inter-positional Polytetrafluoroethylene (PTFE) synthetic vascular graft.

Mycotic/Infective Native Aortic Aneurysms: Results After Preferential Use of Open Surgery and Arterial Allografts.

OBJECTIVE: Mycotic/infective native aortic aneurysms (INAA) are managed heterogeneously. In the context of disparate literature, this study aimed to assess the outcomes of INAA surgical management and provide comprehensive data in alignment with recent suggestions for reporting standards. METHODS: A retrospective review of patients presenting with INAA from September 2002 to March 2020 at two institutions was conducted. In hospital mortality, 90 day mortality, overall mortality, and infection related complications (IRCs) were the study endpoints. Overall survival and IRC free survival were estimated, and predictors of mortality tested using uni- and multivariable analyses. RESULTS: Seventy patients (60 men [86%], median age 68 years [range 59 - 76 years]) were included. Twenty (29%) were ruptured at presentation. INAA location was thoracic in 11 (16%) cases, thoraco-abdominal in seven (10%), and abdominal in 50 (71%). Half of the abdominal INAAs were suprarenal. Two INAAs were concomitantly abdominal and thoracic. Pathogens were identified in 83%. The bacterial spectrum was scattered, with rare Salmonella species (n = 6; 9%). Open surgical repair was performed in 66 (94%) patients, including five conversions of initially attempted endovascular grafts (EVAR), three hybrid procedures, and one palliative EVAR. Vascular substitutes were cryopreserved arterial allografts (n = 67; 96%), prosthesis (n = 2), or femoral veins (n = 1). Kaplan-Meier estimates of overall survival at 30 and 90 days were 87% (95% confidence interval [CI] 76.6 - 93.0) and 71.7% (95% CI 59.2 - 80.9), respectively. The overall in hospital mortality rate was 27.9% (95% CI 1.8 - 66.5). IRCs occurred in seven (10%) patients. The median follow up period was 26.5 months (range 13.0-66.0 months). Chronic kidney disease (CKD) was independently related to in hospital mortality (odds ratio [OR] 20.7, 95% CI 1.8 - 232.7). American Society of Anesthesiologists score of 3 (OR 6.0, 95% CI 1.1 - 33.9), 4 (OR 14.9, 95% CI 1.7 - 129.3), and CKD (OR 32.0, 95% CI 1.2 - 821.5) were related to 90 day mortality. CONCLUSION: Surgical INAA management has significant mortality and a low re-infection rate. EVAR necessitated secondary open repair, but its limited use in this report did not allow conclusions to be drawn.

Clinical and microbiological characteristics and challenges in diagnosing infected aneurysm: a retrospective observational study from a single center in Japan.

BACKGROUND: It is challenging to diagnose infected aneurysm in the early phase. This study aimed to describe the clinical and microbiological characteristics of infected aneurysm, and to elucidate the difficulties in diagnosing the disease. METHODS: Forty-one cases of infected aneurysm were diagnosed in Nagasaki University Hospital from 2005 to 2019. Information on clinical and microbiological characteristics, radiological findings, duration of onset, and type of initial computed tomography (CT) imaging conditions were collected. Factors related to diagnostic delay were analyzed by Fisher's exact test for categorical variables or by the Wilcoxon rank-sum test for continuous variables. RESULTS: Pathogens were identified in 34 of 41 cases; the pathogens were Gram-positive cocci in 16 cases, Gram-negative rods in 13 cases, and others in five cases. Clinical characteristics did not differ in accordance with the identified bacteria. At the time of admission, 16 patients were given different initial diagnoses, of which acute pyelonephritis (n = 5) was the most frequent. Compared with the 22 patients with an accurate initial diagnosis, the 19 initially misdiagnosed patients were more likely to have been examined by plain CT. The sensitivities of plain CT and contrast-enhanced CT were 38.1% and 80.0%, respectively. CONCLUSIONS: In cases of infected aneurysm, diagnostic delay is attributed to non-specific symptoms and the low sensitivity of plain CT. Clinical characteristics of infected aneurysm mimic various diseases. Contrast-enhanced CT should be considered if infected aneurysm is suspected.

Infected aortic aneurysm caused by Streptococcus pyogenes: A case report.

We reported the case with infected abdominal aortic aneurysm (AAA) caused by Streptococcus (S.) pyogenes. A seventy-seven-year-old man, who had the history of uncontrolled diabetes mellitus (DM), complained fever and abdominal pain. Abdominal computed tomography scan revealed the aneurysm above common iliac artery with false lumen. On admission, laboratory tests found marked elevation of inflammatory biomarkers. Thereby the infected AAA was suspected and blood culture was taken. The administration of meropenem (MEPM) and daptomycin (DAP) was started. Next day he underwent abdominal aortic replacement with prosthetic graft and debridement because of persistent abdominal pain and the enlargement of aneurysm. S. pyogenes in blood culture samples was identified by Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry. Same result was obtained from the tissue samples of the resected AAA. Then the diagnosis of infected AAA caused by S. pyogenes was made. Since isolated S. pyogenes showed the susceptibility to antibiotics tested including penicillin, antibiotics were changed to ampicillin (ABPC) for the de-escalation of antibiotics. He had kept the administration of ABPC for 4 weeks and transferred to another hospital for the further treatment of DM. The aneurysms by S. pyogenes are extremely rare, but we should note that S. pyogenes could induce the aneurysms.

An infected aneurysm of the vertebral artery following cervical pyogenic spondylitis: a case report and literature review.

BACKGROUND: An important complication of pyogenic spondylitis is aneurysms in the adjacent arteries. There are reports of abdominal aortic or iliac aneurysms, but there are few reports describing infected aneurysms of the vertebral artery. Furthermore, there are no reports describing infected aneurysms of the vertebral arteries following cervical pyogenic spondylitis. We report a rare case of an infected aneurysm of the vertebral artery as a complication of cervical pyogenic spondylitis, which was successfully treated by endovascular treatment. CASE PRESENTATION: Cervical magnetic resonance imaging (MRI) of a 59-year-old man who complained of severe neck pain showed pyogenic spondylitis. Although he was treated extensively by antibiotic therapy, his neck pain did not improve. Follow-up MRI showed the presence of a cyst, which was initially considered an abscess, and therefore, treatment initially included guided tapping and suction under ultrasonography. However, under ultrasonographic examination an aneurysm was detected. The contrast-enhanced computed tomography (CT) scan showed an aneurysm of the vertebral artery. Following endovascular treatment (parent artery occlusion: PAO), the patient's neck pain disappeared completely. CONCLUSION: Although there are several reports of infected aneurysms of the vertebral arteries, this is the first report describing an infected aneurysm of the vertebral artery as a result of cervical pyogenic spondylitis. Whenever a paraspinal cyst exist at the site of infection, we recommend that clinicians use not only X-ray, conventional CT, and MRI to examine the cyst, but ultrasonography and contrast-enhanced CT as well because of the possibility of an aneurysms in neighboring blood vessels. It is necessary to evaluate the morphology of the aneurysm to determine the treatment required.

Diagnostic Accuracy of PET/CT and Contrast Enhanced CT in Patients With Suspected Infected Aortic Aneurysms.

OBJECTIVE: Infected aortic aneurysms are highly lethal, and management is very demanding, requiring an early diagnosis. The aim of this study was to evaluate the diagnostic accuracy of positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (PET/CT) and contrast enhanced CT (CE-CT) in patients with suspected infected aortic aneurysms. METHODS: PET/CT was performed in patients with clinically suspected infected aortic aneurysms, and additional CE-CT was performed if feasible. Diagnostic accuracy was assessed by two independent readers using a four point grading score for both imaging modalities. Maximum standardised uptake values (SUVmax) were calculated for quantitative measurements of metabolic activity in PET/CT. The reference standard was a combination of clinical presentation, laboratory findings, and imaging. RESULTS: Ten patients were included prospectively in the study, 24 retrospectively; 16 patients (47%) prior to the start of antimicrobial treatment and all 34 patients prior to any vascular intervention. Thirteen of the 34 patients had an infected aortic aneurysm (38%). Proven infected aortic aneurysms were all metabolically active on PET/CT with a median SUVmax of 6.6 (interquartile range 4.7-21.8). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for the diagnosis of infected aortic aneurysm was 100%, 71%, 68%, 100%, and 82%, for reader 1 and 85%, 71%, 65%, 88%, and 77%, for reader 2. Respective values for CE-CT, performed in 20 patients (59%), were 63%, 75%, 63%, 75%, and 70%, for reader 1 and 88%, 50%, 54%, 86%, and 65%, for reader 2. CONCLUSION: The diagnostic accuracy of PET/CT in the detection of infected aortic aneurysms (n = 13) is high, and higher than CE-CT. While PET/CT demonstrates an excellent sensitivity, its specificity is hampered because of false positive findings.

Infected aortic aneurysm caused by Helicobacter cinaedi: case series and systematic review of the literature.

BACKGROUND: Helicobacter cinaedi is rarely identified as a cause of infected aneurysms; however, the number of reported cases has been increasing over several decades, especially in Japan. We report three cases of aortic aneurysm infected by H. cinaedi that were successfully treated using meropenem plus surgical stent graft replacement or intravascular stenting. Furthermore, we performed a systematic review of the literature regarding aortic aneurysm infected by H. cinaedi. CASE PRESENTATION: We present three rare cases of infected aneurysm caused by H. cinaedi in adults. Blood and tissue cultures and 16S rRNA gene sequencing were used for diagnosis. Two patients underwent urgent surgical stent graft replacement, and the other patient underwent intravascular stenting. All three cases were treated successfully with intravenous meropenem for 4 to 6 weeks. CONCLUSIONS: These cases suggest that although aneurysms infected by H. cinaedi are rare, clinicians should be aware of H. cinaedi as a potential causative pathogen, even in immunocompetent patients. Prolonged incubation periods for blood cultures are necessary for the accurate detection of H. cinaedi.

Infected aneurysm of the thoracic aorta probably caused by Bacillus cereus: a case report.

BACKGROUND: An infected aneurysm of the thoracic aorta is a rare clinical condition with significant morbidity and mortality. Patients with fast-growing aortic aneurysms show a high incidence of rupture. Gram-positive organisms, such as the Staphylococcus and Enterococcus species, are the most common cause of infection. CASE PRESENTATION: A 91-year-old man presented at our facility with high grade fever and tachypnea, which he had experienced for the previous two days. He had a history of end-stage renal disease and had been undergoing regular chest computed tomography (CT) follow-up for a left lower lung nodule. CT imaging with intravenous contrast media showed a thoracic aortic aneurysm with hemothorax. Rupture of the aneurysm was suspected. CT imaging performed a year ago showed a normal aorta. Blood samples showed a Bacillus cereus infection. The patient was successfully treated for a mycotic aortic aneurysm secondary to Bacillus cereus bacteremia. CONCLUSIONS: Here, we report a rare of an infected aneurysm of the thoracic aorta probably caused by Bacillus cereus. Although infected aneurysms have been described well before, an aneurysm infected with Bacillus cereus is rare. Bacillus cereus, a gram-positive spore-building bacterium, can produce biofilms, which attach to catheters. It has recently emerged as a new organism that can cause serious infection.

Mycotic aortic aneurysms treated by endovascular repair: initial experience in a single center.

INTRODUCTION: Mycotic aortic aneurysm (MAA) is an uncommon cause of aneurysmal aortic disease. However, it may have an aggressive presentation and a complicated early outcome. Endovascular aneurysm repair (EVAR) of MAA is emerging as an alternative to open repair (OR) for the treatment of these aneurysms, particularly in high-risk surgical patients. We report a single-center experience with the endovascular management of mycotic aortic aneurysms. MATERIAL AND METHODS: Two mycotic abdominal aortic aneurysms were treated with an endovascular stent graft at Centre Hospitalier Régional du Val de Sambre, Belgium. The mean follow-up was 15 months. Technical success was achieved in all two patients. CT-scan follow up showed shrinkage of the aneurysm sac, with no evidence of infection along the stent graft and no signs of endoleakage in all patients. One patient died during the follow-up period from a cause unrelated to the aneurysm. CONCLUSION: EVAR is an effective and safe option and might be a suitable alternative to OR in the absence of predictors of poor prognosis for the treatment of non-complicated forms of MAA.

Mycotic innominate artery aneurysm repair using a bovine pericardial bifurcation prosthesis.

We report the use of a bovine pericardial bifurcation prosthesis to repair a mycotic innominate artery aneurysm.

Endovascular management of infected iliofemoral pseudoaneurysms - a systematic review.

We conducted a systematic review regarding the efficacy and outcome of endovascular treatment of infected iliofemoral arterial pseudoaneurysms with covered stents. 35 cases were identified, including 5 own. 22 pseudoaneurysms were located in the femoral area and 13 in the iliac vessels. The most commonly reported complaints were pulsatile groin mass (40 %), sepsis (37.1 %), active bleeding (31.4 %), and groin infection with purulent discharge (17.1 %). S. aureus (65.7 %) and Streptococcus species (22.9 %) were the most common microbes isolated. Factors for the development of infected pseudoaneurysms were intravenous drug use (20 %), infection of anastomosis in bypass surgery (22.9 %), cancer (14.3 %), history of multiple hip operations (14.3 %), renal transplantation (2.9 %), and obesity (5.7 %). The most commonly used covered stents were Viabahn (22.9 %),Jostent (17.1 %), Fluency (14.3 %), and Wallgraft (14.3 %). In 15 cases, surgical debridement and/or drainage was also performed.The mean follow-up was 15.8 months. There were only 2 cases of stent graft thrombosis (5.7 %). 2 patients required an open vascular bypass procedure at a later stage. One death was attributed to procedure-related complications (2.9 %). The infection rate of the deployed stent graft in follow-up was 3.4 %. Endovascular exclusion of an infected pseudoaneurysm with primary stent grafting and drainage may be an option in high-risk patients.
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Two unusual cases of successful treatment of hypermucoviscous Klebsiella pneumoniae invasive syndrome.

BACKGROUND: A few Japanese cases of hypermucoviscous Klebsiella pneumoniae (K. pneumoniae) invasive syndrome have recently been reported. Although extrahepatic complications from bacteremic dissemination have been observed, infected aneurysms are rare. Furthermore, the primary source of infection is generally a liver abscess, and is rarely the prostate. Therefore, we report two atypical cases of hypermucoviscous K. pneumoniae invasive syndrome. CASE PRESENTATION: The first case was an 81-year-old Japanese man with no significant medical history, who was referred to our hospital for vision loss in his right eye. Contrast-enhanced whole-body computed tomography revealed abscesses in the liver and the prostate, and an infected left internal iliac artery aneurysm. Contrast-enhanced head magnetic resonance imaging revealed brain abscesses. Cultures of the liver abscess specimen and aqueous humor revealed K. pneumoniae with the hypermucoviscosity phenotype, which carried the magA gene (mucoviscosity-associated gene A) and the rmpA gene (regulator of mucoid phenotype A). We performed enucleation of the right eyeball, percutaneous transhepatic drainage, coil embolization of the aneurysm, and administered a 6-week course of antibiotic treatment. The second case was a 69-year-old Japanese man with diabetes mellitus, who was referred to our hospital with fever, pollakiuria, and pain on urination. Contrast-enhanced whole-body computed tomography revealed lung and prostate abscesses, but no liver abscesses. Contrast-enhanced head magnetic resonance imaging revealed brain abscesses. The sputum, urine, prostate abscess specimen, and aqueous humor cultures revealed K. pneumoniae with the hypermucoviscosity phenotype, which carried magA and rmpA. We performed enucleation of the left eyeball, percutaneous drainage of the prostate abscess, and administered a 5-week course of antibiotic treatment. CONCLUSIONS: Hypermucoviscous K. pneumoniae can cause infected aneurysms, and the prostate can be the primary site of infection. We suggest that a diagnosis of hvKP invasive syndrome should be considered in all patients who present with K. pneumoniae infection and multiple organ abscesses.

In situ reconstruction in native and prosthetic aortic infections using cryopreserved arterial allografts.

OBJECTIVES: To evaluate overall survival and complications of cryopreserved arterial allografts in aortic graft infections and infected aortic aneurysms. METHODS: A retrospective review of consecutive patients was conducted with native or prosthetic aortic infections, who underwent local debridement and in situ implantation of a cryopreserved aortic allograft from September 2004 to June 2012 at the Henri Mondor University Hospital. Patient characteristics, indications for allograft implantation, perioperative events, bacteriological data, and events related to follow-up were identified. The primary outcome was overall survival. Overall survival was estimated using the Kaplan-Meier method. Predictors of postoperative mortality were identified using uni- and multivariate analysis with a Cox proportional hazard regression. RESULTS: During the study period, 54 patients (45 [83%] men, mean age 66.2 ± 10.2 years) underwent aortic reconstruction using cryopreserved allografts. Indications were native aortic infection in 17 patients and prosthetic graft infection in 37 patients, including seven aortoenteric fistulae. Twelve aortic reconstructions (22%) were performed as emergency procedures. The median duration of follow-up was 12.1 months (range 0.4-83.6). The 30-day mortality rate was 28%. The overall mortality rate was 39% at a median follow-up of 12.1 months. Early significant postoperative complications occurred in 52% of patients. The graft-related mortality rate was 7%. The graft-related complication rate was 19%. During follow-up, there were two recurrences of aortic infection and two recurrences of allograft limb occlusion. Multivariate survival analysis identified age, chronic renal disease, prosthetic infection, emergent procedure, and coronary disease as independent predictors for postoperative mortality. CONCLUSION: This experience with cryopreserved aortic allografts in aortic reconstructions shows an unsatisfactory 30-day survival rate, as well as a substantial early graft-related complication rate. Longer follow-up is needed in order to support the preferential use of cryopreserved allografts based on their long-term behavior.

Resection of Mycotic Iliac Artery Aneurysm with Extra-Anatomic Bypass: An Alternative to Aneurysmorrhaphy in Difficult Situations.

Mycotic aneurysms of the iliac and other large arteries are rare and are associated with increased morbidity and mortality. Treatment of mycotic aneurysms usually requires modification of the surgical technique done for cases of degenerative or atherosclerotic aneurysms. Degenerative and atherosclerotic fusiform aneurysms are usually managed with aneurysmorrhaphy using a prosthetic graft, which however is not ideal for mycotic aneurysms. Avoidance of prosthetic material at the site of mycotic aneurysm is a better option with higher chances of resolution of infection and favorable patient outcome.

Delayed Stent Infection after Deployment of a Carotid Dual Layer Stent in Dialysis Cases.

Objective: Infection after carotid artery stenting (CAS) is rare. We report two dialysis cases of delayed stent infection associated with a carotid dual-layer stent (DLS), which occurred several months after deployment of the stent. Case Presentations: Case 1: A 74-year-old man receiving dialysis underwent CAS with DLS. Three months after CAS, the patient developed a high fever, neck pain, and neck swelling. Neck CT and carotid ultrasonography (CUS) indicated an abscess around the inserted DLS. The patient was treated with antibiotic agents and fully recovered. Case 2: A 73-year-old man receiving dialysis underwent CAS with DLS. Two months after CAS, this patient also developed a high fever, neck pain, and neck swelling. Contrast-enhanced neck CT indicated inflammatory effusion with an abscess and a giant infectious pseudoaneurysm. Endovascular stent graft reconstruction was employed urgently under antibiotic therapy to prevent its rupture. However, intracranial hemorrhage occurred postoperatively and left hemiparesis remained. Conclusion: Delayed carotid stent infection is a rare but severe complication. The use of a DLS might be avoided during CAS for dialysis cases.

Transarterial embolization for an infected internal iliac artery aneurysm without recurrence for a long period: A case report.

We report an 85-year-old man who underwent transarterial embolization (TAE) for an infected internal iliac artery aneurysm. The patient presented with fever and left lower abdominal pain. Computed tomography (CT) revealed the expansion of a left internal iliac artery aneurysm. We planned surgical treatment for an infected internal iliac artery aneurysm; however, the patient's age and general condition made the surgery high-risk. Therefore, we performed emergency TAE. The patient was administered antibiotics for 4 weeks and discharged on day 33 after the procedure with good progression. A 3-year follow-up CT scan showed aneurysm reduction and no recurrent infections. This case report highlights that TAE can be a treatment option for patients with an infected artery aneurysm.

Ruptured Mycotic Aneurysm of the Superior Mesenteric Artery: A Case Report.

An infected (mycotic) aneurysm of the visceral arteries is an uncommon entity, which may arise from a secondary infection of a preexisting aneurysm or be due to degeneration from a primary infection. Mycotic aneurysms require prompt recognition and definitive treatment; otherwise, there can be devastating morbidity and mortality. We present the case of a 51-year-old female with HIV and Crohn's disease who presented with subacute abdominal pain, nausea, and vomiting and was found to have an ultimately fatal mycotic aneurysm of the superior mesenteric artery. In addition, we discuss the characteristic imaging features of mycotic aneurysms on computed tomography and magnetic resonance imaging.

A case of lymphoma mimicking infected internal iliac artery aneurysm.

BACKGROUND: Malignant lymphoma rarely mimics an infected arterial aneurysm and a ruptured arterial aneurysm because of similar imaging findings, leading to misdiagnosis. The hematomas of ruptured aneurysms are radiologically difficult to distinguish from those of malignant lymphoma in emergency settings. Hence, a definitive diagnosis is crucial to avoid unnecessary surgery. CASE PRESENTATION: A man in his 80s with hematuria and shock vital had right internal iliac artery aneurysm (IIAA) and perianeurysmal fluid retention, which appeared to be a ruptured or an infected aneurysm. Treatment was initiated for infected IIAA instead of for ruptured IIAA. Systemic inflammatory response syndrome developed, and the infectious sources were assessed. Pacemaker lead and urinary tract infections were identified and treated; however, blood pressure was unstable. The aneurysm was treated with endovascular aortic aneurysm repair following antibiotic therapy; however, fluid retention increased, and inflammatory status and hematuria deteriorated. Open surgical conversion was performed to manage the infected lesions. Although an iliopsoas abscess was detected during surgery and nephrectomy and ureterectomy were performed to control the hematuria, analysis of the removed tissues led to the pathological diagnosis of diffuse large B-cell lymphoma (DLBCL). CONCLUSIONS: We encountered a case of DLBCL with imaging findings mimicking an infected internal iliac artery aneurysm, and definitive diagnosis was made more than 2 months after the initial examination. Definitively diagnosing malignant lymphoma around an iliac artery aneurysm based merely on symptoms and imaging findings is extremely difficult. Thus, histological examination should be actively performed in atypical infected aneurysms.