Classic Case

The craniopharyngeal canal (CPC) is an uncommon hereditary anomaly of the midline from the sellar floor to the nasopharynx. This type of congenital malformation can be classified into 3 types that more accurately describe size and associated regional anomalies as follows: type 1, a small incidental canal or hypophyseal canal that is characterized by a diameter of 1.5 mm and can also be associated with other craniofacial or neural congenital anomalies; type 2, a medium-sized canal containing an ectopic adenohypophysis and pituitary dysfunction (this case); type 3A, large canals with associated cephaloceles; type 3B, tumors of the adenohypophysis and associated embryonic tissues; or both (type 3C). CT scan shows a well-corticated defect communicating the pituitary sella to the nasopharynx (A, C, and D, red arrows). The CPC should not be confused with spheno-occipital synchondrosis, which is a normal structure usually horizontally oriented and inferiorly located (A, C, and D, yellow arrows). MR imaging remains the imaging of choice to delineate an ectopic pituitary gland in the nasopharynx, and it can also thoroughly demonstrate displacement of the optic chiasma (A and B, green arrows), the infundibular recess of the third ventricle, and cephalocele (A, blue arrow), in case there are any.