OBJECTIVETo investigate the appearance and clinical value of MRI in the diagnosis of embryonal rhabdomyosarcoma in nasal cavity and paranasal sinuses.

METHODSThe clinical, pathological and MRI findings of five patients with pathology proved embryonal rhabdomyosarcoma in nasal cavity and paranasal sinuses were retrospectively analyzed.

RESULTSThe major clinical symptoms included nasal obstruction (4 cases), exophthalmus (4 cases), decreased eyesight (2 cases), epistaxis (1 case), decreased olfactory sensation (1 case) and restriction of eyeball movement (1 case). All 5 cases involved multi-location. Among them, 4 cases mainly located in the ethmoid sinus, one mainly located in the nasal septum. According to the IRS, 1 case was at stage II, the other 4 cases were at stage III. Compared to the grey matters, on T1 weighted image, the masses were homogenously isointensity in 2 cases, isointensity with patchy hyperintensity in 3 cases. On T2 weighted images, the masses were slightly hyperintensity with patchy hypointensity in 2 cases. Slightly hyperintensity with patchy hyperintensity in 3 cases. All 5 cases were markley heterogeneously enhanced after administration of contrast agents, with patchy of non-enhanced area. Of them, two were grape-like enhanced. Four cases presented with intratumor hemorrhage. Five with bony destruction. All of the 5 cases showed orbits and anterior cranial fossa meningeal involvement.

CONCLUSIONSThere are some special MRI findings in embryonal rhabdomyosarcoma located in nasal cavity and paranasal sinuses. MRI can depict the encroachment of the tumor accurately, and may play an important role in clinical staging and in curative effect evaluation.