Radiology Cases in Pediatric Emergency Medicine
Volume 7, Case 6
Loren G. Yamamoto, MD, MPH

This is a 14 year old female who presents to the emergency department with severe pain in her lower back for the past two hours. She describes the pain as sharp and worse than being stabbed by a knife. She has also had some abdominal pain along with menstrual cramps for the past two days. She took some acetaminophen before coming to the ED and she states that the pain is slightly better. There is no history of fever or chills. There is some suggestion of urgency, but no dysuria. She feels nauseated and she has vomited twice. Her LMP was four weeks ago and she denies any possibility of pregnancy.

Her past medical history is unremarkable. There is no family history of kidney stones.

VS T36.7 (oral), P89, R 20, BP 90/60, oxygen saturation in room air 99%. She is alert and cooperative. She is uncomfortable, but she does not appear to be in severe pain. HEENT unremarkable.

Neck supple. Heart regular without murmur. Lungs clear. No chest tenderness. Her abdomen is soft and non-tender on palpation. Bowel sounds are normoactive. There is no rebound tenderness. Her back is very tender over her mid lumbar spine and this is somewhat worse over her right flank. Her distal pulse are good. She is able to move all her extremities well and she speaks well.

A urine dipstick is positive for blood. Blood studies are drawn and an IV is started. She is given morphine for pain. Her urine pregnancy test is negative and she is sent to radiology for an abdominal series. View abdominal series.

Any abnormalities here? What diagnostic procedure would you order next?
There is a calcified density in the right lower quadrant visible on both views of the abdominal series. This is suspected to be a ureteral stone since her symptoms are consistent with this.

She is given additional doses of morphine to control her pain. Her laboratory studies show a normal CBC (WBC 6,700) and chemistry (normal BUN, creatinine, SGPT and lipase). Her urinalysis shows 5-10 WBCs and 50-100 RBCs. An abdominal ultrasound is performed but she is too uncomfortable to cooperate well and this study is non-diagnostic except for the presence of mild hydronephrosis of her right kidney. An intravenous pyelogram (IVP) is ordered. A 20 minute and a delayed abdominal flat plate are shown below.

An earlier IVP flat plate demonstrates prompt excretion of contrast from the left kidney. The 20-minute IVP shows contrast excretion from the left kidney and a contrast enhanced right kidney without contrast excretion. The delayed IVP (a slightly oblique view) shows delayed contrast excretion from the right kidney confirming an obstruction on the right.

Is the calcified density in the right lower quadrant causing the obstruction?
The IVP demonstrates an obstruction in the right ureter, along with a clinical presentation consistent with ureteral colic. This makes it very likely that she has a ureteral stone. However, the calcified density is very large for a ureteral stone. Additionally, the location of the calcified density is not exactly in the expected path of the ureter. An appendicolith is suspected. Her pain has subsided following the administration of analgesics. Interestingly, she did not have much abdominal pain on initial presentation, since she was mostly complaining of back pain. Now that her back pain is under better control, she is complaining of some abdominal pain, but it is not severe. The severity of her nausea has been fluctuating. She is given some promethazine and her nausea has now subsided.

A urologist is consulted for her ureteral obstruction and a pediatric surgeon is consulted for the possibility of appendicitis. An abdominal CT scan is ordered; however, the radiologist is reluctant to give her a second dose of IV contrast for the CT scan. She is followed clinically and she passes a small amount of tissue in her urine which contains a tiny stone. Her abdominal pain persists and she eventually undergoes an appendectomy which shows an early appendicitis with an appendicolith.

This is an interesting case in that the patient actually has two different acute conditions simultaneously. Although the calcified density on her abdominal series appeared to be too large for a ureteral stone, this was assumed to be a large ureteral stone because of her clinical presentation. In fact, the stone was felt to be too large to pass spontaneously, so the possibility of lithotripsy or surgical retrieval of the stone were discussed. Calcifications in the right lower quadrant should always raise the possibility of an appendicolith and acute appendicitis. As a pitfall, clinicians may attribute this finding to other causes such as vascular calcification, gynecological calcification, intestinal contents (ingested sand or gravel), or as in this case, a ureteral stone. A CT scan without and then with contrast may have been a more optimal study which would have identified the ureteral stone and the appendicolith.

Loren Yamamoto, MD, MPH, Professor of Pediatrics, University of Hawaii John A. Burns School of Medicine.Loreny@hawaii.edu