14 QUATERCENTENARY STUDIES IN PATHOLOGY 



Microscopically, these tumours show the following facts : the mucous 

 membrane surrounding them is partially destroyed, the superficial parts 

 thereof are worn away, the Lieberkuhnian crypts are to some extent 

 atrophied, only their deeper-lying half is left, and these remnants show 

 considerable alteration of the individual cells composing them, viz.^ the 

 luminal end of the cells is indistinct, vacuolated or empty. The crypts 

 are separated from each other by a mass of new tissue, which, in breadth, 

 is about equal to that of one of the crypts, and consists of cellular tissue 

 composed of mononuclear round cells with but little protoplasm, and also 

 of short spindle cells. A few ova are seen lying in the interglandular 

 new tissue, but never inside a crypt itself As this partially destroyed 

 mucous membrane nears the tumour, it becomes greatly hypertrophied 

 and is lifted up by the projecting papilloma, so as to form, for a short 

 distance, a covering to the latter, but it soon is broken through by the 

 growing tumour which is thus devoid of a mucous lining. The tumour 

 itself arises from an over growth of the submucous tissue, this tissue is 

 greatly increased in thickness along the bowel, is composed of young 

 connective tissue interspersed by numerous groups of small round cells, 

 and is crowded with ova. Portions of the hypertrophied submucous 

 tissue, projects outwards through the mucous membrane, carrying with it 

 enormous numbers of ova, and showing, in the polyp itself, a great 

 number of congested, ectatic capillaries, and a tissue which is less highly 

 developed than the general hypertrophied sub-mucosa, being composed 

 of young fibroblasts, some delicate fibrils, and numerous round mono- 

 nuclear cells. These mononuclear cells are in greatest abundance over 

 the surface of the polyp, where they form a richly vascular cap of cellular 

 tissue, which often has itself a thin covering of precipitated fibrinous 

 material in which a few round cells are present. The papilloma contains 

 great numbers of ova, principally in its most central part, the ova lie free 

 in the young fibroblastic tissue, and occasionally one or two are seen 

 lying inside a congested capillary. It is, in many instances, on the 

 acclivities only of the papilloma that remains of Lieberkuhnian crypts 

 are seen, though some disorganised glandular masses are found nearer 

 the summit of the tumour. Such of the true mucous membrane as 

 exists on the surface of the papillomata {i.e., the portions spared by the 

 faecal attrition) is greatly hypertrophied, the glandular crypts being con- 

 siderably increased in length and often widened into cyst-like cavities, 



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