pelvis AP view

History:
75 year old woman with left hip pain

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Findings:
It was reported as 'bilateral degenerative changes; otherwise unremarkable'.

The patient came for x-ray 6 months later with worsening left hip pain

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Findings:
Reported as 'Expansile lyic lesion involving the left iliac wing, which needs CT'.

CT:


Findings:
A large lytic expansile agressive lesion involving the left iliac bone. Differentials include expansile metastasis, lymphoma, plasmacytoma or primary bone tumor

Lesson:
1. Grossly, the initial radiograph appears to be normal. But, on careful inspection, one can see the asymmetry in the 'normal' lucenies of the iliac wings. The lucency of the normal right iliac wing is triangular with apex facing downwards with rather striaght margins; where as, the lucency of the abnormal left iliac wing extends more inferiorly and the margins, although fairly well defined, are irregular.
2. In all hip pains, if the hip is normal, look outside the hip for the cause!