TUMORS. 



529 



and tubular formations. Acinous glands, as a rule, are lined by 

 cuboidal or short columnar epithelia, which are often stratified j 

 while tubular glands are lined by columnar epithelia, which are 

 sometimes ciliated. The regularity in the arrangement of the 

 epithelia, their fine and uniform granulation, and the compara- 

 tively fine granulations of the nuclei, are, in many instances at 

 least, distinguishing points for the diagnosis of an adenoma 

 under the microscope. 



FIG. 219. CUBOIDAL EPITHELIA, FROM THE NEIGHBORHOOD 

 OF THE COLUMNAR EPITHELIA. 



a, nucleus surrounded by a light space, a sc-called vacuole ; b, empty vacuole, nucleus 

 dropped out; c, epithelium with two nuclei; d, epithelium with a bright, homogeneous 

 nucleus; e, "thorns," or filaments of living matter in the cement substance; /, thorns in- 

 creased in size ; g, enlarged thorns, united into a shining, spindle-shaped body ; h, pear-shaped 

 body between epithelia; i, rows of lumps and rods ; fc, medullary elements ; I, newly formed 

 epithelium wedged in between the old. Magnified 1200 diameters. 



Adenoma is a common tumor, and occurs most frequently in 

 the following localities : 



In the skin glandular new formations are observed, starting 

 from the sebaceous glands as sebaceous cysts, as molluscum seba- 

 34 



