Bone tumors in the pelvis presenting growth during pregnancy.

Among 56 cases of a giant cell tumor of bone (GCT) and 52 cases of chondrosarcoma (CSA) in our series, four patients were discovered to have a tumor in the pelvic bone that grew in size during pregnancy. These four rare cases are described here. They include three cases of a GCT in the sacrum and one case of a CSA in the innominate bone. The dextran-coated charcoal assay and immunohistochemical techniques demonstrated the independence of these tumors from hormonal regulation despite the growth stimulated during pregnancy. It was concluded that the delay in detection of these tumors in the pelvis was just related to the opportunity afforded for unexpected growth during pregnancy. Surgical management was difficult due to the delay in tumor detection. The initial complaints such as pain, discomfort, or numbness around the pelvis were misinterpreted as symptoms of pregnancy. It should be kept in mind that during pregnancy, any pain or numbness in the pelvic region could be the direct result of a tumor in the pelvic bone.