Spine Pseudogout Following Breast Cancer Treatment: A Report of Two Cases.

Calcium pyrophosphate disease (CPPD) is a commonly diagnosed crystal-induced disease that typically presents as acute monoarticular or oligoarticular arthritis. It is less commonly seen in the spine, and its clinical importance in this area is still relatively understudied. Isolated spinal CPPD is quite rare; a diagnosis of spinal CPPD is almost always accompanied by peripheral CPPD. We present two patients who were both being treated for breast cancer. They underwent spine surgery and were subsequently diagnosed with isolated CPPD of the spine by pathology specimens. Neither patient had a history of CPPD prior to the surgery. We hypothesize there is a potential link between breast cancer and its treatment and isolated spinal CPPD; however, more research and case reports are needed to begin making conclusions and understand the relevance.