Changes of the sella turcica in chromophobic adenomas and eosinophilic adenomas.

Abstract

The increase in therapeutic modalities for the various lesions in the intrasellar and suprasellar areas necessitates an accurate differential diagnosis. This should be advanced as far as possible by the plain skull film examination. Our study is directed toward the evaluation of the osseous changes in and about the sella turcica in chromophobic adenomas and eosinophilic adenomas. Our primary aim is to compare the classical description of the roentgen changes in each of these pituitary tumors in surgically and pathologically verified material. Previous Studies Since Oppenheim (22) in 1899 first reported roentgenographically demonstrable changes in a pituitary tumor, the literature dealing with the radiologic diagnosis of these adenomas has become extensive. There seems to be agreement that the osseous changes caused by intrasellar tumors in most instances can be distinguished from those of suprasellar lesions (2–4, 6, 8, 11, 14–19, 29, 30). With respect to the differentiation between the various types of pituitary tumors, however, different opinions are held. In general, American and British authors (12, 24, 29) do not emphasize this aspect, which has been dealt with by Austrian, German, French, and Scandinavian writers (3, 6, 9, 11, 14, 15, 19, 23, 26, 30). Many features considered characteristic of each type of adenoma were described previously by the Vienna school, and gradually a classical description has evolved which can be summarized as follows. The sella of the eosinophilic adenoma is typically balloon-shaped, indicating that the sellar entrance is either minimally widened or not at all. The angle between the planum sphenoidale and the anterior wall of the sella is acute, and the dorsum sellae is not tilted backward. In addition, the dorsum sellae is not significantly eroded. These findings are in contrast to the roentgen changes in the chromophobic adenomas, in which a cup-shaped or “open” sella is considered typical. Also, the angle between the planum and the anterior sellar wall is obtuse, and the sellar entrance is widened, primarily because of the backward tilt of the dorsum. The dorsum sellae is described as eroded, and the asymmetrical enlargement of the sella as usually present in the chromophobic adenomas. Also, it is thought that in the chromophobic adenoma the sella is usually much larger than in the eosinophilic. In later years, Lindgren (14, 15) and Mayer (19), among others, maintained that this description generally holds true, but others (17, 31) do not entirely concur. On the basis of material consisting of 4 eosinophilic and 34 chromophobic adenomas, Mahmoud (17) concluded that his findings did “not confirm the statement of Lindgren of a greater incidence of the balloon sella in esoinophilic rather than chromophobic adenomas.” In fact, many opinions seem to be based on limited material, especially with respect to eosinophilic adenomas.