Patient: On July 30, a bump was found under the chin, which was painful to touch. The patient was six weeks old, a boy. Laboratory tests and ultrasound diagnosis: two hypoechoic nodules of variable size, 1.0*0.7 and 0.6*0.7 CM, were seen slightly to the left of the submandibular region. parenchymal heterogeneous nodules in the submandibular region, not excluding lymph node enlargement. I have been on antibiotics for four days, and I feel no pain when I touch it, but the bag is still there. Chen Peng: First of all, from the ultrasound results and the effective use of anti-inflammatory drugs should first be considered as inflammatory lymph node enlargement, but further diagnosis should be decided after the hospital visit. A thyroglossal cyst is a benign cystic swelling that occurs in the tissue remaining when the thyroid gland descends from the root of the tongue to the lower part of the neck during development, usually in the midline region of the neck, rarely seen in the side. Sublingual cysts are storage cysts caused by blockage of the ducts of the sublingual gland and are visible in the mouth as a translucent blue bulging area under the tongue, which can flow egg-white like drawn fluid if broken. The submandibular type of sublingual gland cyst may not be visible in the mouth, but a soft bulge is visible under the jaw, and the ultrasound examination reports a cystic mass. This child can be observed after the application of 5-7 anti-inflammatory drugs and may not go down completely in the end. Close observation and, if necessary, a visit to an oral and maxillofacial surgeon should first disregard the thyroglossal duct cyst and sublingual gland cyst.