[The excisional range of tracheal infiltration of the thyroid cancer]

We studied histopathologically the infiltrative modes in 17 cases with tracheal infiltration of the thyroid cancer, and studied its excisional range. 1) Macroscopically, morphologies in the regions of the trachea were divided into 3 types. Types I and II were noted in 4 cases for each and Type III was noted in 9 cases. 2) When the infiltrative modes in the trachea were divided into localized and infiltrative types, localized type was noted in all cases of type I, and infiltrative type was noted in all cases of Type II. The both types were noted in 2 cases and 7 cases of Type III, respectively. 3) Infiltrative region of the tracheal mucous membrane in all cases of Types I and III was localized in the range of the infiltrative region of the extratracheal mucous membrane. The infiltrative region of the tracheal mucous membrane was wider in 2 cases of Type II comparing with that of the extratracheal mucous membrane. It is considered that radical treatment of types I and III can be obtained by the excisional range of the infiltration of the extratracheal mucous membrane. Operative diagnosis is necessary because wider range infiltration of the cancer is observed in the tracheal mucous membrane of Type II.