ANCA-NEGATIVE GRANULOMATOSIS WITH POLYANGITIS: HUNT FOR A ZEBRA

Abstract

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Granulomatosis with polyangiitis (GPA) stays high on the rheumatological differential in cases where there is renal insufficiency, hematuria, cartilaginous abnormalities or necrotizing lesions noted in the upper and lower respiratory tract. Serological testing is often done along with tissue diagnosis. ANCA is generally positive in such scenarios supplementing the diagnosis of GPA. Rarely ANCA can be negative. GPA should therefore be considered in the differential of negative ANCA, since there is high likely hood of misdiagnosis and unnecessary investigation along with a delay in treatment. CASE PRESENTATION: 56-year-old male who occasionally smokes cigars and had been exposed to asbestos from car brakes, complained of bloody urine. Patient had cystoscopy and TURBT performed revealing cystitis cystica. He had CT chest, abdomen and pelvis performed showing several bilateral pulmonary nodules. Couple of speculated nodules previously seen in right lower lobe increased in size. PET scan showed increased uptake in right lower lobe lung nodule. CT-guided lung biopsy was done which showed exuberant acute on chronic inflammation with necrosis. That was negative for fungal organism on gram stain and culture. No malignant cells were found. All serological work up was negative including ANCA. Repeat CT scan in five months showed that right lower lobe pulmonary nodule was increasing in size. Considering hematuria, CT scan and pathology findings there was a high suspicion for granulomatosis with polyangiitis. Patient was taken to VATS of right lower lobe wedge resection to confirm the diagnosis. Pathology report showed necrotizing granulomatous inflammation with geographic necrosis confirming the diagnosis of granulomatosis with polyangiitis. There was no evidence of malignancy. DISCUSSION: In less than 10% cases patients have been reported with granulomatosis with polyangiitis. Unless there is high degree of suspicion kept in cases with clinical scenario suggestive for granulomatosis with polyangiitis even in cases of ANCA negative patients, there is high likelihood of missing the diagnosis. We suggest in cases with strong clinical suspicion, even though ANCA is negative and bronchoscopic biopsy is not revealing further invasive testing is warranted to establish a correct diagnosis. CONCLUSIONS: Negative serologies should not preclude invasive testing for adequate tissue specimen in patients with a strong history suggestive for GPA in order to prevent delay in diagnosis and management. It is well documented that patients with the history of Polyangitis with granulomatosis has involvement of Urinary bladder and are at high risk for cystitis. Cytitis has potential of worsening to cystitis cystica. Reference #1: Falk RJ, Jennette JC. ANCA small-vessel vasculitis. J Am Soc Nephrol. 1997;8(2):314–22. Reference #2: Finkielman JD, Lee AS, Hummel AM, Viss MA, Jacob GL, Homburger HA, et al. ANCA are detectable in nearly all patients with active severe Wegener’s granulomatosis. Am J Med. 2007; 120(7):643.e9–14. Reference #3: Hagen EC, Daha MR, Hermans J, Andrassy K, Csernok E, Gaskin G, et al. Diagnostic value of standardized assays for anti-neutrophil cytoplasmic antibodies in idiopathic systemic vasculitis. EC/BCR Project for ANCA Assay Standardization. Kidney Int. 1998;53(3):743–53. DISCLOSURES: No relevant relationships by Amnah Andrabi, source=Web Response No relevant relationships by Kashif Aslam, source=Web Response No relevant relationships by Bindu Gandrapu, source=Web Response No relevant relationships by Preeyanka Sundar, source=Web Response