Delayed diagnosis of primary non-Hodgkin's lymphoma of the sacrum

Primary non-Hodgkin's lymphoma of bone is a rare, malignant hematologic tumor affecting most commonly persons in the fourth decade of life. The tumor produces predominantly osteolytic lesions usually in the femur and pelvic bones and, very rarely, may present with spinal epidural involvement. The authors discuss an interesting case of primary non-Hodgkin's lymphoma of bone involving the sacrum with epidural invasion, in which the atypical imaging findings along with negative biopsy results delayed diagnosis.