18A192

To Compare the Clinical and Histological Diagnosis in Patients with Giant Cell Arteritis in a Single Centre

Author(s)

Fatemah Baron1, Rajneet Singh1, Caroline Brodie2, Bernadette Lynch1

Department(s)/Institutions

1 Rheumatology Department, University College Hospital Galway (UCHG) 2 Pathology Department, University College Hospital Galway (UCHG)

Introduction

Giant cell arteritis (GCA) is a large vessel vasculitis of unknown aetiology, which, if left untreated could result in permanent blindness. Annual incidence of GCA is 15-35/100,000 per year. The British Society of Rheumatology (BSR) recommends a temporal artery biopsy (TAB) in all suspected cases of GCA. BSR guidelines recommend a minimum TAB length of ≥2.5cm to diagnose GCA .

Aims/Background

To analyse the total number of referrals for GCA requiring a TAB and to compare the clinical diagnosis of GCA to the histological diagnosis at University College Hospital Galway.

Method

We identified all patients who underwent a temporal artery biopsy from the histopathology database between January 2017 and October 2017. We excluded any patient who was not evaluated by the Department of Rheumatology. A retrospective analysis was completed to identify patient characteristics, presentation, histological findings and length of TAB in this cohort.

Results

A total of 12 patients were identified, who had a TAB over a ten month period between January and October 2017. The majority of the cohort was female (67%). 92% of patients were over 60 years old with a mean age of 68 years old. The most common symptoms identified were headache (30%) and visual disturbance (28%). Out of 12 TAB, ten biopsies (84%) were negative. Five (50%) of these patients were treated clinically as GCA. Further analysis of the five negative biopsies revealed that four (80%) were of inadequate length (3mm-12mm, mean 8.8mm). Two TAB (17%) were inconclusive. One of these patients was treated clinically as GCA and the TAB was of an inadequate length (8mm).

Conclusions

GCA is a well described condition. Traditionally, all patients were referred for TAB, for histological confirmation of the diagnosis. This study highlights the challenge of obtaining an adequate TAB length for histopathological analysis. The TABUL study highlighted the utility and superiority of Ultrasound scanning of the temporal artery in GCA which we are exploring further in our Rheumatology department.