Medical Student Case Study: Horseshoe Kidney in an Infant

Emma Simpson

August 2013

Konrad Bienia MD & Eric Sutherland MD

• 5 mo old boy• Ex-preemie (35 weeks)• Previous admission for community-acquired

viral infx• O/p visit for assessment of HSK seen on

prenatal US

• Fever (Tmax 101’)

• FTT (Zeroeth percentile in all parameters.)• Stage 1 Chronic Kidney Disease• Abnormal urinalysis

The Patient

• Because who doesn’t love embryology?

Renal Embryology

4 weeks 9 weeks

http://academic.amc.edu/martino/grossanatomy/site/Medical/CASES/R&R/pop%20ups/hydronephrosis%20anspop_up4.htm

• Crossed, fused ectopia– The estimated incidence is around 1 out of 1,000

births–Male: Female; 2:1

• Horseshoe Kidney– 0.25% of the general population–More common in men.

Fusion Abnormalities

Horseshoe Kidney Pathology

• MAINLY asymptomatic – autopsy finding• UTI and fever in neonates• Abdominal surgery: BEWARE• Mostly of interest to radiology nerds.• Can have sequelae related

to poor drainage…

Clinical History & Physical Exam

6http://elettrogenica.tumblr.com/page/2

• Depends on symptoms. • Chronic Kidney Disease

in a newborn– Premature

birth/trisomies/non-aneuploidic anomalies

– Acute Kidney Injury becoming chronic• Congenital• Hypoxic ischemic injury• Toxic injury

DDx

http://en.wikipedia.org/wiki/Autosomal_dominant_polycystic_kidney

• Clinical Sx–Nausea, abdominal discomfort, kidney

stones and urinary tract infections at greater frequency than those without renal fusion.

• Risks–Trauma–Renal calculi–Transitional cell carcinoma of renal

pelvis/Wilms tumor–Chronic Kidney Disease

What does a diagnosis mean?

• Ultrasound• Fluoroscopy - IVU• CT and MRI

• ACR: Do not irradiate babies• PLUS: Very specific area to be imaged, and

can be easily visualized. Babies are small. Cheap and fast.

Imaging Modalities for HSK

https://www.akronchildrens.org/cms/procedures_tests/Ultrasound_infant_hip/

Normal US Right Kidney

http://www.ultrasoundpaedia.com/normal-kidney/

Normal US Kidney

http://www.ultrasoundpaedia.com/normal-kidney/

Left Longitudinal Retroperitoneal US: HSK

MRN: 6566544

Right Longitudinal Retroperitoneal US: HSK

MRN: 6566544

Transverse Retroperitoneal US

MRN: 6566544

• No tx for HSK• Adequate hydration• Symptomatic management• In this pt:– Lost to follow-up–Mom moved out of state– Social Services concerns

Horseshoe Kidney

Thank You

• Gupta, M., A. K. Pandey, and N. Goyal. "Horseshoe Kidney--a Case Report." Nepal Med Coll J 9.1 (2007): 63-6. Print.

• http://radiopaedia.org/• Carmody, J. B., and J. R. Charlton. "Short-Term Gestation,

Long-Term Risk: Prematurity and Chronic Kidney Disease." Pediatrics 131.6 (2013): 1168-79. Print.

• http://en.wikipedia.org/wiki/Horseshoe_kidney• http://www.chop.edu/img/urology/horseshoe-kidney.html• http://renalfellow.blogspot.com/2008/09/horseshoe-kidney-

versus-crossed-fused.html

References

17