Adenoma. 391 



canalicular systems are in no way in communication with the 

 emerging ducts of the noniuil t^huuls, an accumulation of secre- 

 tory material and desquamated epithelial cells is likely to be 

 retained in their passages and spaces : thus in an adenoma of 

 the mammary gland milk is found as a pathological product ; in 

 follicular adenomata of the thyroid, masses of colloid matter; in 

 adenomata of mucous glands, mucin. As a result of the reten- 

 tion of such material the walls of the canals and alveoli become 

 stretched, and this feature, together with continuous enlargement 

 of their surfaces from increase of the epithelial lining and the 

 connective tissue framework, may make the distended cavities 

 visible to the naked eye. To tumors thus altered and containing 

 cavities filled with fluid the term cysfadc)io}na is applied ; and 

 where villous projections of the lining membranes extend into 

 the cavities the growth is known as cystadcnonia papilliferum 

 phylloidcs. 



The growing vascular connective tissue of the adenomatous 

 structure is sometimes the seat of haemorrhagic effusions or 

 oedematous swelling, due to passive congestion and transudation 

 caused by kinking of the folds and villi projecting into the 

 cysts. Other regressive changes, as fatty degeneration or coagu- 

 lation necrosis, may also be observed. In some instances the 

 stroma of the tumor is a tissue very rich in cells and of a 

 reticular structure resembling a sarcoma or myxoma (adenosarcoma, 

 adeiioinyxoma, adenoma sarcomatodes, my.vomatodes) . 



Finally glandular tumors, which in typical cases are usually 

 distinctly limited from the organ in which they are situated, 

 may become atypical and send out infiltrating processes into the 

 surrounding tissue, penetrating into the lymph vessels and 

 bloodvessels and thus assume the character of a malignant fibro- 

 epithelial growth. These forms are known by the names adenoma 

 destruens, adenoearcinoma [)nalignaut adenoma]. 



Two points may be considered in attemptmg an explanation 

 of the setiology of adenomata. The definitely circumscribed 

 nodular adenomata w'hich develop in or close to parenchymatous 

 organs are doubtless of foetal origin, coming from misplaced, 

 independently developing parts of a gland. Those growing as 

 single or multiple tumors from mucous surfaces, sometimes 

 occupving extensive areas of the mucous membrane, often show 

 in themselves, just as the neighboring parts of the membrane 

 mav also show, evidences of chronic inflammatory change, recog- 

 nizable bv cellular infiltration and by giving rise to a mixed secre- 



