Abnormal bone marrow signal on MRI heralding oncologic diagnoses: A single institution review.

Abstract

1580 Background: The increased use of magnetic resonance imaging (MRI) has resulted in increased numbers of incidental findings. Oncologists often receive consults for workup of "abnormal marrow signal." As there is no standard evaluation for such findings and the yield of additional evaluation is unclear, we performed a retrospective study of patients evaluated with MRI at Tufts Medical Center (TMC). Methods: With IRB approval, TMC radiology reports were searched from 5/9/05-12/31/08 with GE Centricity Radiology Information System 2.2. Included patients had MRI reports containing the phrases “abnormal bone marrow” or “heterogeneous bone marrow”, but no clear etiology stated. Further workup, including referral to a subspecialist, laboratory, radiographic, or pathologic evaluations, final diagnosis, and last follow up were collected. Results: 29,508 MRIs were performed and 77 patients met search criteria. Median age was 58 years with a median follow-up of 41 months at TMC after qualifying MRI. 40/77 (52%) of patients had either an MRI of the lumbar spine or hip with 21/77 (27%) undergoing work-up for the marrow findings. Evaluations included CBC (38%), SPEP (24%), quantitative immunoglobulins (14%), free light chains (10%), peripheral blood flow cytometry (5%), bone marrow biopsy (19%), skeletal survey (14%), bone scan (48%), CT scan (24%), biopsy of other site (24%), and subspecialty referal (48%, 29% to oncology). Definitive diagnosis was assigned in 11/21 (52%) cases, with 5 being malignancies (1 follicular lymphoma, 2 multiple myeloma, 2 lung cancer). Three patients were later diagnosed with malignancy (breast cancer, myelodysplastic syndrome, merkel cell carcinoma) at a median of 19 months. Overall, 10% of patients with abnormal marrow on MRI were diagnosed with a malignancy. Conclusions: Incidentally noted abnormal or heterogeneous bone marrow signal on MRI was not inconsequential. Of those patients who underwent evaluation for the finding, 24% were diagnosed with a malignancy. We conclude that abnormal bone marrow findings on MRI should not be ignored, and given the rates of malignancy in our series, oncologists are ideally suited for this task.