Incidentally detected pancake kidney: a case report

Background: Congenital anomalies of the urinary system are very common and have extremely varied presentation. Among them, the most rarely found structural anomaly is the pancake kidney. When both kidneys are fused along their medial surfaces to form a round-shaped single renal mass, it is termed as pancake kidney. In this case report, a pancake kidney was incidentally detected in a girl. The majority of individuals who have pancake kidney are usually asymptomatic but surgeons should be aware of coexisting malformation of other organs and its potential risk of developing malignancy.

Case presentation: A 12-year-old Bengali girl presented to our out-patient department with mild, dull aching, lower abdominal pain and dysuria. She had no history of fever, hematuria, menstrual abnormality, pelvic inflammatory disease, or trauma. Urine examination showed traces of albumin and 10-12 pus cells/high-power field. She had normal kidney function test but a digital X-ray of her kidney, ureter, and bladder region failed to demonstrate bilateral renal tissue shadows. Ultrasonography of her whole abdomen showed normal intra-abdominal organs except for empty bilateral renal fossa. A multi-detector computed tomography scan of her whole abdomen revealed one round-shaped mass measuring approximately 9 cm (vertical) × 10 cm (horizontal) in the pelvic cavity. That mass was finally identified as a pancake kidney. She was prescribed antibiotics based on urine culture and sensitivity test that cured her symptoms. She was advised to follow-up regularly in our out-patient department to evaluate her kidney function and to rule out any neoplastic change.

Conclusions: This condition can be managed conservatively, if the individual remains asymptomatic, by regular monitoring of renal function. Surgeons should remain alert for the development of infections, any obstructive manifestations leading to calculus formation, and any malignant changes. The individual should be careful in avoiding trauma to low-lying pelvic kidney. Extensive surgeries should be avoided and only selective procedures should be done so that the patient may lead a normal lifestyle.

Keywords: Ectopic kidneys; Empty renal fossa; Pancake kidney; Unascended/low-lying fused kidneys.