Question
A 68-year-old woman comes to the emergency department because of abdominal pain for 3 days. Physical examination shows guarding and tenderness to palpation over the left lower abdomen. Test of the stool for occult blood is positive. A CT scan of the abdomen is shown. Which of the following mechanisms best explains the patient’s imaging findings?
| A. |
Failed neural crest cell migration
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| B. |
Absent tissue differentiation
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| C. |
Impaired organ ascent
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| D. |
Incomplete organ fusion
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Show Answer
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Correct Answer � C
Explanation
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Answer C) Impaired organ ascent
This patient’s CT scan shows a horseshoe kidney. Her abdominal symptoms are likely unrelated to the renal pathology as a horseshoe kidney is often an incidental finding.
Impaired organ ascent
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Impaired organ ascent explains the presence of this horseshoe kidney at an inferior position relative to normal kidneys.
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The fused inferior poles of the horseshoe kidneys get caught under the inferior mesenteric artery, impeding the normal ascension of the kidneys to their retroperitoneal locations.
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However, this obstructed migration is generally benign, does not affect kidney function, and is not commonly associated with ischemia or abdominal pain.
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This radiographic finding is most likely incidental and not associated with this patient’s current complaint.
