Roentgen Therapy of Pituitary Adamantinomas (Craniopharyngiomas)

Apituitary adamantinoma is an encapsulated cystic tumor containing muddy-looking fluid filled with cholesterol crystals and grumous material. The weight of evidence at present is strongly in favor of the derivation of this tumor from embryonic epithelial rests in the pars tuberalis of the pituitary body. This portion of the pituitary arises from an ectodermal outpouching of the roof of the primitive mouth cavity, and it is probable that dental elements and transitional forms of epithelium are enclosed in this outpouching. Although pituitary adamantinomas resemble embryonic enamel organs microscopically, no enamel or evidence of enamel formation is found in these tumors. One is justified, however, in speaking of them as resembling the embryonic enamel organ, and, since the term “adamantinoma” is descriptive, it probably is the best designation. Pituitary adamantinomas present one of the most difficult problems in neurosurgery. The close anatomic relationship of vital structures which are intolerant to trauma makes successful excision an extremely difficult procedure. It is only natural, therefore, that more conservative methods of treatment have been tried. On the basis of their microscopic structure, these tumors would appear to be radioresistant, and indeed they have been considered so by the majority of radiologists. Most of the reports in the literature are unsatisfactory, since they concern cases in which the diagnosis has not been verified and in which, for the most part, the tumors have been unresponsive to roentgen therapy. Bailey (1), in his review of 242 verified tumors of the brain in which roentgen therapy was used, said that suprasellar cysts were not treated, since no results were to be expected from irradiation. Béclère (2) also considered tumors of Rathke's pouch and all suprasellar tumors refractory to roentgen therapy. It was not until 1937 that any report was published concerning the favorable results of roentgen irradiation of histologically verified pituitary adamantinomas. Carpenter, Chamberlin, and Frazier (3) reported 4 cases in which the improvement produced by roentgen therapy was definitely greater than that obtained by surgical measures alone. In 3 of these cases the diagnosis was verified histologically, but in the fourth case irradiation was used after the cystic tumor was aspirated. The authors' conclusion was that, even though the tumor might not be destroyed by roentgen rays, the tumor cells which produced the secretion forming the cyst seemed to have their secretory character destroyed by irradiation. In 1938 Schwartz (9), in his article on tumors of the hypophysis, said that roentgen therapy of pituitary adamantinomas was moderately successful. He felt that the method of treating these tumors should be essentially the same as for other pituitary tumors except that the dosage should be reduced in young patients.