A 33-year-old woman with a history of appendectomy, cholecystectomy and H. pylori presented with a two year history of episodic right lower quadrant abdominal pain associated with nausea, emesis and unintentional 40 pound weight loss. She had multiple emergency department visits and a prior extensive evaluation at an outside hospital, including CT of abdomen and pelvis, MRE, EGD, colonoscopy, and exploratory laparoscopy, all of which were negative. Her physical exam on admission revealed a BMI of 19.0 but was otherwise unremarkable. Laboratory analysis was notable for elevated amylase and lipase to 220 and 125, respectively. She received supportive treatment for suspected pancreatitis and reported resolution of symptoms the following day. However, her symptoms recurred with her first attempts at ambulating. Using an online symptom checker from her hospital bed, she diagnosed herself with nephroptosis. Urology was consulted, and an intravenous urogram and ultrasound identified abnormalities of the right kidney which were only present on upright views. Upon standing, her right kidney descended 4 cm more than the left and had evidence of mild hydronephrosis. In the left lateral decubitus view, her right kidney crossed the midline. Surgery was recommended, and she underwent nephropexy for symptomatic nephroptosis one month later. She reported symptom improvement at her outpatient follow-up visit.
Nephroptosis is a condition in which there is renal descent of 5 or more centimeters (or 2 vertebral bodies) upon standing upright. It is commonly detected radiographically and can be seen in up to 20% of women. It is typically associated with low or low-normal BMI and most often affects the right kidney. Pain due to nephroptosis is not well recognized. It involves acute abdominal pain and vomiting which occurs when upright, and is relieved when the patient assumes a recumbent or knee-chest position. This is thought to occur when descent of the mobile kidney causes ureteral kinking, stimulation of the visceral nerves due to traction on the renal hilum, and/or narrowing of the renal artery. Physical exam may demonstrate a palpable abdominal mass when the patient is in an upright position. Urinalysis may have abnormalities including proteinuria and hematuria. Nephroptosis can be diagnosed by intravenous urogram obtained in supine and upright positions, which demonstrates abnormal renal descent and resultant obstructive physiology with hydronephrosis. Treatment is surgical and involves transperitoneal nephropexy or placement of a circle nephrostomy tube.
Hospitalists frequently encounter patients with unspecified abdominal pain. Symptomatic nephroptosis should be considered in the differential diagnosis of positional abdominal pain, particularly in thin women. This patient had a classic presentation of a condition that, while seemingly rare, likely remains under-recognized.
To cite this abstract:Lopez AN. Nephroptosis: An Unexpected Cause of Abdominal Pain. Abstract published at Hospital Medicine 2016, March 6-9, San Diego, Calif. Abstract 650. Journal of Hospital Medicine. 2016; 11 (suppl 1). https://www.shmabstracts.com/abstract/nephroptosis-an-unexpected-cause-of-abdominal-pain/. Accessed April 1, 2020.