CEACAM5 and schwannoma: We believe that there are 3 main reasons that lumbar paravertebral schwannomas are misdiagnosed: lumbar paravertebral schwannomas are rare and clinical manifestations are nonspecific; no specific tumor markers have been found that are indicative of the disease (eg, cancer antigen [CA]199, CEA, AFP, CA125, CA153); and tumor growth is slow, asymptomatic during the early phase, the retroperitoneal space of the tumor growth site is large, and the location is deep, so it is difficult to detect by physical examination.