A case of secondary orbital rhabdomyosarcoma invading from the paranasal sinus and presenting with epiphora as an initial symptom

We report a case of orbital rhabdomyosarcoma that arose from a primary tumor in the paranasal sinus. An 18-year-old boy was brought to our hospital with epiphora. Computed tomography and magnetic resonance imaging showed that a tumor in the right ethmoid sinus had invaded the orbit. Examination of a biopsy specimen from a mandibular lymph node showed tumor cells of medium size with a high nuclear/cytoplasmic ratio, and cytoplasm that stained with periodic acid-Schiff. Immunochemical examination showed many cells positive for desmin, muscle actin, and myoglobin. Our case brings to 65 the number of cases of rhabdomyosarcoma reported in Japan. Epiphora was the initial symptom in 1 other case besides ours (2/65=3.5%). It appears that there has been a recent increase in the incidence of rhabdomyosarcoma originating in the paranasal sinuses and invading the orbit.