Pelvic renal ectopia, an incidental finding.

To cite: Aslam F. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2016218894 DESCRIPTION A woman aged 33 years presented with a 2-week history of non-traumatic back pain, progressive bilateral lower limb weakness with paraesthesia and urinary incontinence. She had a background of recurrent urinary tract infection and hypertension. Clinical examination revealed reduced power bilaterally (grade 3/5) and reduced reflexes but normal tone. She was unable to walk. Abdominal examination was unremarkable and per rectal examination was normal with good anal tone. She was apyrexial with a blood pressure of 132/ 86 mm Hg and heart rate of 84 bpm. Admission blood tests (including FBC, CRP, U&E, bone profile, magnesium, B12 and folate) were normal. Urine dipstick was also normal. An urgent whole-spine MRI excluded cord compression. It did however reveal a soft tissue mass in the pelvis anterior to the S1 vertebral body, just left to the midline extending into the presacral space. This was initially thought to be a lymph node mass (figure 1). Further examination of coronal and axial MR images identified an absent left kidney in the retroperitoneal space and re-evaluation of the mass raised suspicion of an ectopic pelvic kidney (figures 2 and 3). Subsequent investigation via ultrasound scan confirmed this vascular, solid organ within the pelvis abutting the urinary bladder, measuring 8.6 cm (figure 4). Additional assessment with urography studies is beneficial for visualising the structure and abnormalities within the urinary system. Following neurology review, the patient had a lumbar puncture (which detected raised protein (8 g/L) and normal white cell count in the cerebrospinal fluid) and a normal electromyogram. She was diagnosed with Guillain-Barré syndrome.