Lumbar spinal stenosis secondary to calcium pyrophosphate crystal deposition (pseudogout)

A 62-year-old man demonstrated symptoms, signs, and radiographic evidence of lumbar spinal stenosis and intraoperative pathologic findings of tophaceous deposition in the ligamentum flavum. Although there have been reports of cervical calcium pyrophosphate dihydrate crystal deposition (CPPD) with neurologic compression, this report appears to be the first case of lumbar spinal stenosis secondary to CPPD. Cervical calcium pyrophosphate dihydrate crystal deposition should be added to the differential diagnosis of spinal stenosis.