Lumbar Extradural Pseudogout Mass Manifesting as Radiculopathy: A Case Report

BACKGROUND: Calcium pyrophosphate dihydrate (CPPD) disease, also known as pyrophosphate arthropathy or pseudogout, is defined as CPPD deposition within the articular cartilage. It was first described in 1962. The representative locations where CPPD disease occurs include the most common knee joint, followed by the wrist joint. Joint swelling and pain are the most common clinical presentations, and the typical differential diagnosis is degenerative arthritis. Microscopically, the specimen demonstrates numerous positively birefringent rhomboid shaped crystals when examined under polarized light. CASE REPORT: We present a 70-year-old female with right painful sciatica accompanied by coexisting affected limb soreness and clumsiness. Her final diagnosis was unusual lumbar extradural tumoral pseudogout that was worth noticing. Tumoral CPPD deposition was excised after laminectomy. Subsequently, her symptoms were abated postoperatively without a need for more analgesics. Her neurological function was properly recovered. CONCLUSION: This is a rare report to proffer pseudogout in an unfamiliar lumbar extradural location, which is an unexpected diagnosis. Making a precise tentative diagnosis for the ongoing disease entity might be difficult for the clinicians because the clinical manifestations of this pathology are similar to those of other common degenerative lumbar spinal diseases.