Photo Quiz

A Helmet to the Flank


FREE PREVIEW. AAFP members and paid subscribers: Log in to get free access. All others: Purchase online access.


FREE PREVIEW. Purchase online access to read the full version of this article.

Am Fam Physician. 2014 Jul 15;90(2):119-120.

A 16-year-old boy presented to the emergency department approximately 30 minutes after he was injured during a football game. He was hit in the left flank by a helmet during a tackle. He felt short of breath and had sharp, stabbing pain on deep inspiration. He was able to speak in full sentences. He was healthy and was not taking any medications or supplements.

Physical examination revealed a heart rate of 82 beats per minute, respiratory rate of 20 breaths per minute, and a blood pressure of 130/74 mm Hg. His left flank was tender to palpation, but there was no ecchymosis or palpable abdominal mass. Urinalysis and serum creatinine findings were normal. Computed tomography was performed (Figures 1 and 2).


Figure 1.


Figure 2.

Question

Based on the patient's history, physical examination, imaging, and laboratory findings, which one of the following is the most likely diagnosis?

A. Congenital ureteropelvic junction obstruction.

B. Congenital ureterovesical junction obstruction.

C. Renal cell carcinoma.

D. Renal papillary necrosis.

E. Traumatic kidney rupture.

Discussion

The answer is A: incidental finding of congenital ureteropelvic junction obstruction. The patient had a left flank contusion, and computed tomography showed isolated severe hydronephrosis with disproportionate dilatation of the renal pelvis and parenchymal thinning. Ureteropelvic junction obstruction is the most common cause of congenital hydronephrosis.1 Because this condition is often asymptomatic, late, incidental diagnosis is common. The condition causes increased kidney pressure, which results in blunting of the renal calyces and hydronephrosis. The obstruction is most often caused by intrinsic stenosis in the proximal ureter, and less commonly by extrinsic compression from a mass or aberrant renal vessel. Ureteropelvic junction obstruction is a risk factor for kidney rupture; therefore, this patient was advised to avoid contact sports until further evaluation.2

Ureterovesical junction obstruction is the second most common cause of congenital hydronephrosis.1 Obstruction occurs at the junction of the distal ureter and bladder. Imaging findings include megaureter and hydronephrosis. Secondary causes include extrinsic tumors, retroperitoneal fibrosis, and neurogenic bladder.3

Renal cell carcinoma is the most common kidney tumor in persons older than 15 years. Imaging shows a heterogeneous mass extending from normal kidney tissue. The classic presentation is the triad of flank pain, gross hematuria, and renal mass, but all three findings are present in only 19% of patients.4 Although this is a common cancer in adults, it accounts for only 2% of malignant kidney tumors in children.5

Renal papillary necrosis most often presents with hematuria. It can be painless, or pain can occur because of urinary obstruction from the sloughed cells. Analgesic nephropathy, sickle cell disease, sickle cell trait, and diabetes mellitus are risk factors.6 Computed tomography findings may include small, lobulated kidneys; blunting and clubbing of the renal calyces at the papillary tips; calcification of necrotic papillae; and sloughed papillae observed as triangular filling defects within the collecting system.

Traumatic rupture of the kidney from blunt trauma is common in high-energy collisions. Radiographic findings include evidence of tissue injury, subcapsular hematoma, contrast extravasation, and perinephric or retroperitoneal fluid collection.7 Relative to trauma to the urinary tract, renal contusion and laceration are the most common injuries reported.

View/Print Table

Summary Table

DiagnosisSymptomsPreferred imaging modalityRadiographic findings

Congenital ureteropelvic junction obstruction

Asymptomatic or intermittent flank pain

Ultrasonography

Hydronephrosis with tapering of dilated renal pelvis at the level of the proximal ureter

Congenital ureterovesical junction obstruction

Asymptomatic or intermittent flank pain

Ultrasonography

Hydronephrosis, megaureter

Renal cell carcinoma

Triad of flank pain, gross hematuria, and renal mass is the classic presentation

Unenhanced CT followed by three-phase CT

Enhancing renal mass

Renal papillary necrosis

Painful or painless hematuria

Computed tomographic urography

Small, lobulated kidneys; blunting and clubbing of renal calyces; filling defects from sloughing and calcification of papillae and contrast pooling into the site of sloughed papillae

Traumatic kidney rupture

Hematuria, flank pain, possible hemodynamic instability

Three-phase CT

Tissue injury, subcapsular hematoma, contrast extravasation, perinephric or retroperitoneal fluid collection


CT = computed tomography.

Summary Table

DiagnosisSymptomsPreferred imaging modalityRadiographic findings

Congenital ureteropelvic junction obstruction

Asymptomatic or intermittent flank pain

Ultrasonography

Hydronephrosis with tapering of dilated renal pelvis at the level of the proximal ureter

Congenital ureterovesical junction obstruction

Asymptomatic or intermittent flank pain

Ultrasonography

Hydronephrosis, megaureter

Renal cell carcinoma

Triad of flank pain, gross hematuria, and renal mass is the classic presentation

Unenhanced CT followed by three-phase CT

Enhancing renal mass

Renal papillary necrosis

Painful or painless hematuria

Computed tomographic urography

Small, lobulated kidneys; blunting and clubbing of renal calyces; filling defects from sloughing and calcification of papillae and contrast pooling into the site of sloughed papillae

Traumatic kidney rupture

Hematuria, flank pain, possible hemodynamic instability

Three-phase CT

Tissue injury, subcapsular hematoma, contrast extravasation, perinephric or retroperitoneal fluid collection


CT = computed tomography.

Address correspondence to T. Keefe Davis, MD, at davis_tk@kids.wustl.edu. Reprints are not available from the authors.

Author disclosure: No relevant financial affiliations.

REFERENCES

show all references

1. Brown T, et al. Neonatal hydronephrosis in the era of sonography. AJR Am J Roentgenol. 1987;148(5):959–963....

2. Smith M, et al. Trauma cases from Harborview Medical Center. Rupture of a ureteropelvic junction-obstructed kidney in a 15-year-old football player. AJR Am J Roentgenol. 2003;180(2):504.

3. Manzoni C. Megaureter. Rays. 2002;27(2):83–85.

4. Ganick DJ, et al. Index of suspicion: case 1: abdominal trauma, pain, and tenderness associated with anemia and hematuria in a 14-year-old boy. Case 2: ptosis, diplopia, tremors, and mild exophthalmos in a 9-year-old girl. Case 3: persistent cough, shortness of breath, and localized decreased aeration in an 18-year-old girl. Pediatr Rev. 2011;32(11):495–501.

5. Grovas A, et al. The National Cancer Data Base report on patterns of childhood cancers in the United States. Cancer. 1997;80(12):2321–2332.

6. Jung DC, et al. Renal papillary necrosis: review and comparison of findings at multi-detector row CT and intravenous urography. Radiographics. 2006;26(6):1827–1836.

7. Shewakramani S, et al. Genitourinary trauma. Emerg Med Clin North Am. 2011;29(3):501–518.

Contributing editor for Photo Quiz is John E. Delzell, Jr., MD, MSPH.

A collection of Photo Quizzes published in AFP is available at http://www.aafp.org/afp/photoquiz.

The editors of AFP welcome submissions for Photo Quiz. Guidelines for preparing and submitting a Photo Quiz manuscript can be found in the Authors' Guide at http://www.aafp.org/afp/photoquizinfo. To be considered for publication, submissions must meet these guidelines. E-mail submissions to afpphoto@aafp.org.



Copyright © 2014 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact afpserv@aafp.org for copyright questions and/or permission requests.

Want to use this article elsewhere? Get Permissions


Information From Industry

More in AFP


Related Topic Searches


Editor's Collections


More in Pubmed

Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now

Navigate this Article