INTRODUCTION:Vasculitis conditions are often serious and sometimes fatal diseases, therefore it is paramount to diagnose correctly and treat appropriately. Mimics of primary vasculitis can include either non-inflammatory syndromes or secondary vasculitis where the underlying etiology of the vasculitis is being driven by infection, malignancy, drug-effect or other.AREAS COVERED:This review comprises six individual cases of vasculitis mimics. Each case is presented and the clinical, radiographic, and histological features that distinguish the case from primary vasculitis are highlighted. Key mimics in large, medium and small vessel vasculitis are outlined.EXPERT OPINION:The diagnosis of vasculitis requires a comprehensive assessment of clinical, radiographic, and histologic features. Clinicians should be familiar with mimics of primary vasculitis conditions. In the case of non-inflammatory mimics, it is important to differentiate from primary vasculitides in order to avoid unnecessary and potentially harmful immunosuppression. For cases of secondary vasculitis, identification of the correct etiologic cause is critical because treatment of the underlying stimulus is necessary for successful management and outcomes.

Background: Retroperitoneal fibrosis (RPF) commonly affects the infrarenal abdominal aorta (irAA) and manifests with periaortic soft tissue thickening (pASTT). RPF can be either idiopathic (primary) or secondary. Secondary causes include malignancy and infection and thus biopsy aids in differentiating etiologies. Data describing the safety and efficacy of pASTT biopsy sampling using computed tomography (CT)-guidance is limited. Objectives: To assess the safety and efficacy of periaortic biopsies using computed tomography (CT)-guidance among a large single institution cohort of patients with RPF. Methods: Patients undergoing CT-guided percutaneous pASTT biopsy from June 1, 1999 through September 30, 2022 were identified retrospectively. All patients were required to have radiographic evidence of soft tissue thickening/mass in direct contact with the irAA and have had CT-guided biopsy performed. Patients with biopsies of periaortic lymph nodes or the perivascular space of the iliac vessels or inferior vena cava were excluded. Routine laboratory screening thresholds prior to biopsy included INR <1.6 and platelet count >50 x10^9/L. Anticoagulation/antiplatelet agents were held prior to biopsy. Charts were reviewed by a physician abstractor. Demographics, biopsy features, and outcomes were collected. Complications were graded based on common terminology criteria for adverse events (CTCAE): categories 1 and 2 being minor, and categories 3-5 considered major. Results: 83 patients (28 females, 55 males) with 84 biopsies of the pASTT at the level of the irAA were identified. Mean age at biopsy was 58 (range 31-83) years. Biopsy approach was paraspinal in 73 (87%) and anterior abdominal in 11 (13%). Mean number of passes was 5 (range 1-12). A 17/18 gauge needle size was most commonly used (67/84), followed by 19/20 gauge (15/84). One biopsy used a 15/16 gauge device and one report did not specify needle size. Local anesthesia only was used in 18 (21%) biopsies, moderate anesthesia in 61 (73%) and anesthesia type was not specified in 5 (6%). Three of 84 (3.6%) biopsy events had minor bleeding at entry site. A single (1.2%) patient had a major bleeding complication with left rectus sheath hematoma from anterior abdominal approach requiring embolization of left inferior epigastric pseudoaneurysm. No post procedural infections were observed. Biopsy of the irAA soft tissue confirmed diagnosis following 73/84 (87%) biopsies (Table 1) with mean thickness at biopsy site 14.4 mm (range 3.4-27.9). In the 11 procedures where the diagnosis was not achieved by initial biopsy, 6 were due to insufficient tissue for histologic characterization [mean thickness 15.1 mm (range 5.2-25.4)] and 5 were due to concern for alternative etiology despite sufficient tissue. Among these 11 cases, 5 had subsequent open surgical biopsy, 2 had repeat CT-guided irAA soft tissue biopsy, 1 had alternative site biopsied and 3 were clinically followed (Table 2). Conclusion: In this study, percutaneous CT-guided infra-renal pASTT biopsy was considered safe and confirmed diagnosis in 87% of cases. Final diagnosis differed from pre-biopsy suspicion in 34%, highlighting benefit of this procedure. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.

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The patient, a 69-year-old female, presented with new-onset headache and facial and sinus pain initially treated by primary care with azithromycin for presumed sinusitis. Her erythrocyte sedimentation rate (ESR) was 114 mm/hour, and her C-reactive protein (CRP) level was 173.5 mg/l. Following antibiotics, she developed “thickened” tongue with white plaque (A) and was treated with oral nystatin for thrush. However, she subsequently developed masticatory and lingual claudication, a distal left tongue ulcer (A and B), and left temporal discomfort. A left temporal artery biopsy (TAB) showed histopathological findings consistent with giant cell arteritis (GCA). A retinal examination and fluorescein angiogram showed evidence of left eye retinal ischemia with presence of cotton wool spots, though asymptomatic and without visual field deficits. High-dose oral prednisone (100 mg/day) was started on the day of TAB (B). Within 48 hours, the headache and jaw and tongue claudication resolved. Seven days later, marked improvement in the tongue ulcer (C) was noted, and inflammatory markers had improved (ESR: 40 mm/hour; CRP level: 14.2 mg/l). Given significant clinical response, a prednisone taper without adjunct tocilizumab was used. A follow-up evaluation 3 months later (prednisone dose 10 mg/day) showed full resolution of the tongue ulcer (D), and the patient remained asymptomatic with a normal ESR (5 mm/hour) and CRP level (5.4 mg/l). Lingual manifestations in GCA include claudication, pain, edema, pallor, ulceration, and necrosis. Tongue claudication has been reported in approximately 3% of patients with GCA (1); however, tongue ulceration and frank necrosis are rare. GCA is considered the most common noninfectious vascular etiology of tongue necrosis, and its presence should prompt consideration and investigation for GCA. Visual ischemic features have been reported in up to 38% of patients with GCA with tongue ulceration or necrosis (2); therefore, all patients with GCA with tongue claudication or ulceration/necrosis should undergo detailed ophthalmologic examination. Prompt recognition and treatment initiation is paramount, and in this case, glucocorticoids preserved vision and resolved cranial and lingual symptoms. Disclosure Form Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Objectives ANCA-associated vasculitis (AAV) is currently categorized under the small vessel vasculitides. There is limited knowledge about large vessel involvement in AAV (L-AAV), mainly described in case reports and small series. L-AAV can involve temporal arteries (TA-AAV), aorta (A-AAV), and periaortic soft tissue (PA-AAV). We sought to characterize the features of patients with L-AAV.Methods Patients older than 18 years at diagnosis of TA-AAV, A-AAV and PA-AAV seen at the Mayo Clinic, Rochester between 1 January 2000 and 31 December 2021 were identified through a proprietary medical text search algorithm. Patients were included if diagnosed with L-AAV, fulfilled 2022 ACR/EULAR classification criteria for GPA, MPA or EGPA, had positive ANCA test results, and had more than one outpatient or inpatient visit.Results The study cohort consists of 36 patients with L-AAV. Of those, 23 had p-ANCA and/or MPO-ANCA, and 13 had c-ANCA and/or PR3-ANCA. Mean (s.d.) age at AAV diagnosis was 63.4 (12.79) years; 20 (56%) were male. Seventeen patients had TA-AAV, 10 had A-AAV and 9 had PA-AAV. Most patients (n = 25, 69%) were diagnosed with large vessel vasculitis and AAV within a 1-year timespan. Twenty-five (69%) patients had histopathological confirmation of AAV diagnosis in a location other than temporal artery, aorta or periaortic soft tissue. Glucocorticoids (36/36), rituximab (19/36) and methotrexate (18/36) were the most frequent treatments.Conclusion This is the largest single-centre cohort of patients with L-AAV to date. AAV can involve large arteries, albeit infrequent. AAV-targeted therapy should be considered in patients with L-AAV.

We read with interest the case reported by Dr. Paquale Finelli1 which highlighted the importance of evaluating patients with non-invasive arterial imaging to identify radiographic features of large-vessel vasculitis (LVV). We agree with the author that evaluating for extracranial LVV is advised among patients presenting with stroke, elevated inflammatory markers, systemic inflammatory symptoms, and absence of traditional vascular risk factors; particularly if a thromboembolic source is not identified.

OBJECTIVES:To evaluate the epidemiology, presentation and outcomes of patients with chronic periaortitis from 1998 through 2018.METHODS:An inception cohort of patients with incident chronic periaortitis from January 1, 1998 through December 31, 2018, in Olmsted County, Minnesota was identified based on comprehensive individual medical record review utilising the Rochester Epidemiology Project medical record linkage system. Inclusion required radiographic and/or histologic confirmation of periarterial soft tissue thickening around at least part of the infra-renal abdominal aorta or the common iliac arteries. Data were collected on demographic characteristics, clinical presentation, renal and radiographic outcomes, and mortality. Incidence rates were age and sex adjusted to the 2010 United States white population.RESULTS:Eleven incident cases of chronic periaortitis were identified during the study period. Average age at diagnosis was 61.8±13.4 years. The cohort included 9 men (82%) and 2 women (18%). Age- and sex-adjusted incidence rates per 100,000 population were 0.26 for females, 1.56 for males and 0.87 overall. Overall prevalence on January 1, 2015 was 8.98 per 100,000 population. Median (IQR) length of follow-up was 10.1 (2.5, 13.8) years. Overall mortality was similar to the expected age, sex, and calendar estimates of the Minnesota population with standardised mortality ratio (95% CI) for the entire cohort 2.07 (0.67, 4.84).CONCLUSIONS:This study reports the first epidemiologic data on chronic periaortitis in the United States. In this cohort of patients with chronic periaortitis, men were 4 times more commonly affected than women. Mortality was not increased compared to the general population.