MRI for evaluation of myeloid sarcoma in adults: a single-institution 10-year experience

The purpose of this study was to evaluate the utilization and role of MRI in the management of myeloid sarcoma in adults.

A retrospective study of 69 patients with pathologically proven myeloid sarcoma included 25 patients (16 men, nine women; mean age, 55 years; range, 22-78 years) who underwent pretreatment MRI at our institution from January 2001 to October 2011. A total of 71 MRI examinations were evaluated by two radiologists in consensus.

A total of 41 sites of involvement of myeloid sarcoma were noted, most commonly bone (13/25, 52%), muscle (7/25, 28%), CNS (6/25, 24%), and head and neck (6/25, 24%). Nineteen sites were noted on MR images obtained for evaluation of a new sign or symptom, most commonly musculoskeletal (11 sites) and CNS (six sites). Fifteen sites were noted on MR images obtained for further evaluation of a previously detected abnormality, most commonly in the abdomen and pelvis (seven sites). Seven lesions were incidentally found on MR images obtained for other myeloid sarcoma-related indications, most commonly in the head and neck (three lesions) and musculoskeletal system (three lesions). The mean size of measurable lesions was 5.6 cm (range, 1-20 cm). Compared with muscle, the lesions were isointense (31/41, 75.6%) or hypointense (10/41, 24.4%) on T1-weighted images and mildly hyperintense (39/41, 95.1%) on T2-weighted images and had homogeneous enhancement (29/38, 76.3%).

In our experience, MRI was most often used for evaluation of bone, muscle, the CNS, and the head and neck region. MRI is useful for evaluation of new musculoskeletal and CNS findings and for further evaluation of known abdominopelvic masses. Incidental findings are often musculoskeletal or in the soft tissues of the head and neck.