BCG-induced granulomatous prostatitis—an incidental finding on FDG PET-CT Christopher Wilkinson a, ⁎ , Fahmid Chowdhury a,b , Andrew Scarsbrook a,b , Jonathan Smith a a Department of Radiology, St James University Hospital, Leeds, LS9 7TF, United Kingdom b Department of Nuclear Medicine, St James University Hospital, Leeds, LS9 7TF, United Kingdom Received 5 July 2011; received in revised form 31 August 2011; accepted 14 September 2011 Abstract We present a case of granulomatous prostatitis that presented in a rare way as an incidentally discovered focus of increased FDG activity within the prostate on PET-CT in a patient who had previously undergone intravesical bacille Calmette-Guérin treatment for bladder cancer. FDG uptake is commonly discovered in organs distant from the region of primary interest on PET-CT and so it is important to be aware of the potential causes of this. © 2012 Elsevier Inc. All rights reserved. Keywords: Granulomatous prostatitis; PET-CT; BCG; Incidental findings 1. Introduction It is well recognized that imaging with 2-[ 18 fluorine]- fluoro-2-deoxy-D-glucose (FDG) positron-emission tomog- raphy–computed tomography (PET-CT) results in unex- pected findings discovered outside the region of primary interest [1,2]. With the widespread use of PET-CT in oncological imaging, it is likely that these incidental findings will impact on an increasing number of patients. As increased FDG uptake is not specific for malignant processes (occurring in any tissue undergoing increased glycolytic activity), many such incidental findings on PET-CT represent benign entities. It is therefore important to understand the potential benign as well as malignant causes for increased FDG uptake in any particular anato- mical region [3]. Here we present a case of one such benign condition, granulomatous prostatitis, that presented inciden- tally as a focus of increased FDG activity within the prostate in a patient who had previously undergone intravesical bacille Calmette-Guérin (BCG) treatment for bladder cancer. 2. Case report A 63-year-old Caucasian male underwent half-body FDG PET-CT following the finding of eccentric duodenal thickening on CT as part of surveillance for radically treated transverse colon carcinoma. He had an additional history of recurrent superficial bladder transitional cell carcinoma (TCC) of the bladder treated with transurethral resection and intravesical BCG instillation. PET-CT demonstrated abnor- mal FDG uptake within the duodenal lesion consistent with recurrent colorectal carcinoma, but also revealed focal tracer uptake in the right anterior prostate at the mid-gland level (Fig. 1). The patient had no local or systemic symptoms or signs attributable to this finding. While inflammatory conditions were considered, this initially raised concern for either synchronous carcinoma of the prostate or invasive TCC, and therefore transrectal ultrasound (Fig. 2) and biopsy were performed. Ultrasound revealed a focus of decreased echogenicity centrally within the mid gland to apex region of the right prostatic lobe, which was felt to be Clinical Imaging 36 (2012) 413 – 415 ⁎ Corresponding author. Departments of Radiology and Nuclear Medicine, St James University Hospital, Beckett Street, Leeds, LS9 7TF, United Kingdom. E-mail address: ctlwilkinson@hotmail.com (C. Wilkinson). 0899-7071/$ – see front matter © 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.clinimag.2011.09.004