1. Brief medical history: Male, 69 years old, was admitted to the hospital with a week-long physical examination finding right upper lung nodule. Chest CT suggested: nodular shadow in the posterior segment of the right upper lung lobe, subelliptical in shape, surrounded by short burrs, with a maximum diameter of about 1.3 cm. Bronchoscopy did not show any significant abnormality. Pulmonary function tests were approximately normal. Preoperative diagnosis: left upper lung heteroplasm. Proposed surgery: thoracoscopic resection of the posterior segment of the upper right lung lobe. 2. Brief description of the operation: During dissection of the arteries and bronchi of the posterior segment of the right upper lung lobe, extensive lymph nodes around the hilum were found to be enlarged and closely adhered to the hilar structures, so the intraoperative decision was changed: right upper lung lobectomy + mediastinal lymph node removal. The lung lobectomy went relatively smoothly, and after the 2R/4R lymph node dissection, milky fluid appeared in the area and tended to increase, and the exploration revealed that there was a continuous flow of white celiac fluid from a break slightly in front of the right superior intercostal vein into the odd vein arch at the upper edge of the odd vein arch. The right supracostal vein was also ligated in which the odd vein arch was preserved. The distal end could not be found at this time, and the tissue section after lymph node dissection behind the superior vena cava was carefully explored, but any place where there might be a severed end was closed with hemo-lock. The postoperative analysis speculated that the severed lymphatic tract might be a variant of the thoracic duct or a primary branch of the thoracic duct. Because of the high flow and milky color of the severed end. From the anatomical position, the thoracic duct should not appear in this area under normal circumstances. If it is present, it is highly likely that the thoracic duct has undergone a variation: in this location, the thoracic duct has not undergone a right-to-left deviation, and secondly, it is directly superior to the right jugular angle. In the second case, it is possible that the larger traffic branch between the thoracic duct and the right lymphatic duct has been severed. During surgical lymph node dissection for lung cancer, postoperative celiac disease occurs from time to time, and celiac leakage may occur even when the thoracic duct trunk has been deliberately protected, mainly because of the high number of variants in the thoracic duct. In order to prevent the occurrence of celiac disease after surgery, the following issues should be noted during mediastinal lymph node dissection: ①In the case of lymph node dissection, if possible, choose ultrasound knife or ligasure to operate, even if the lymphatic vessels or lymphatic ducts are inadvertently damaged during surgery, ultrasound knife or ligasure can always coagulate and embolize them, thus reducing or avoiding the occurrence of celiac disease. (ii) In most medical centers, the ligasure or ultrasound knife can be used to coagulate and embolize the lymphatic vessels. ② In most medical centers, the operator’s choice of instruments is dominated by the electric knife and electrocoagulation hook, which are far less effective in stopping bleeding than the ultrasonic knife or ligasure, so the operation should be performed without large blocks or bundles of cuts whenever possible. In these areas, the tubular or striated tissues seen must be handled carefully, and must not be cut off without further treatment. The tubular or striated tissues in these areas have only three structures: small and medium-sized blood vessels, lymphatic vessels (or lymphatic ducts) and the vagus nerve and its branches. The vagus nerve and its branches are easy to identify during surgery, while the blood vessels and lymphatic ducts are sometimes less easy to identify, whether they are blood vessels or lymphatic ducts. Because the vessels here are mainly some bronchial arteries and small vessels supplying the lymph nodes as well as the posterior intercostal vessels and branches of the odd vein, etc., ligating them will not have a major impact on the organism. In addition, anatomical literature shows that there is a rich collateral circulation between the thoracic duct and the body vein, and ligation in either part of the chest and neck generally does not impair the lymphatic transmission to the central circulation.