A 3-year-old boy presented with acute facial nerve weakness. Serologic screening was negative for Lyme disease. An empirical diagnosis of Bell palsy was made. Over the next 4 weeks, the patient's facial weakness worsened, with subsequent drooling, slurred speech, and decreased oral intake. He developed facial swelling and ear and jaw pain. His medical history was remarkable for transient anuria at birth, with a normal renal ultrasonogram. Physical examination showed an ill-appearing child with a House-Brackmann grade III right facial paresis and a cervicofacial mass. The mass, which measured 5 cm in greatest dimension, was firm, nontender, and located in the right side of the floor of the mouth and buccal space on bimanual palpation. Neck examination revealed level II, III, and IV firm, mobile lymph nodes measuring approximately 1.5 to 2.0 cm in diameter. Laboratory tests revealed a hematocrit of 27% (reference range, 35%-45%) and a lactate dehydrogenase level of 2900 IU/L (reference range, 56-194 IU/L) (to convert to microkatals per liter, multiply by 0.0167).