Acute crystal deposition arthritis of the pubic symphysis.

A 68-year-old woman presented with an acute onset of lower abdominal pain. A CT scan of the pelvis showed acute crystal deposition arthritis, and her symptoms markedly reduced with non-steroidal anti-inflammatory drugs. Further, a radiographic evaluation of the right knee joint and CT of the cervical spine revealed calcification; calcium pyrophosphate (CPP) crystals were identified in the synovial fluid of the right knee. This established the diagnosis of CPP crystal deposition disease, while the inflammation of the pubic symphysis was considered as acute crystal deposition arthritis related to calcium pyrophosphate dihydrate crystal deposition. Acute crystal deposition arthritis of the pubic symphysis should be considered in the differential diagnosis of lower abdominal pain.