MAST CELLS IN PATHOLOGICAL CONDITIONS 



1. Mast-cell reaction to tumours. Ehrlich (1879) records that he found 

 many mast cells in tumours, 'especially carcinoma', but it was left to his pupil, 

 Westphal (1891), to recognize that the cells tend to congregate chiefly at the 

 periphery of carcinomatous nodules rather than within the substance of the 

 tumour. Westphal (p. 40) states that 'especially around rapidly growing 

 carcinomas the mast cells accumulate in unprecedented numbers' ('in colossaler 

 Menge'). This predilection of mast cells for the environs of tumours has 

 repeatedly been confirmed both for spontaneous tumours (Unna, 1896; Fromme, 

 1906; Bonney, 1908; Weill, 1919; Staemmler, 1921; Higuchi, 1930; Quensel, 

 1933; Michels, 1938; Sylven, 1940; Bali and Furth, 1949) and for experimentally 

 induced new growths (Bierich, 1922; Peyron, 1923; Fabris, 1927; de Vinals, 

 1931; Cramer and Simpson, 1944; Holmgren and Wohlfart, 1947). Sylven 

 (1945) in particular has studied the distribution of metachromatic 'free chromo- 

 trope substance' and the disposition of mast cells in and around mesenchymal 

 tumours. According to Sylven the process of tumour invasion is preceded by 

 the conversion of the adjacent normal connective tissue into a gelatinous 

 matrix rendered metachromatic in part by the release of granular material from 

 tissue mast cells. In slowly growing mesenchymal tumours the preliminary 

 process of digestion of the normal tissue so far outstrips the subsequent 

 utilization of this 'free chromotrope substance' that the tumour is seen to be 

 surrounded by a vivid band of diffuse metachromasia, whereas in more 

 anaplastic growths the metachromatic zone is consumed as fast as it is formed. 

 However, Sylven (1945) himself records that in keloid the generalized meta- 

 chromasia is strongest during the period of most active growth, mast cells 

 appearing later as the 'free chromotrope substance' is fading and differentia- 

 tion is setting in. It has yet to be shown that the metachromasia of 'free 

 chromotrope substance' and of mast cells are histochemically identical, or are 

 even causally related (Holmgren and Wohlfart, 1947; Riley and Drennan, 

 1949; Favilli, 1950). 



There is a second way in which mast cells may be concerned in the growth 

 of an established tumour, namely through the ability of a tumour, especially 

 an epithelial tumour, to induce for itself an internal stroma of blood vessels 

 and fibrous tissue. Several authors have noted that in slowly growing scirrhous 

 carcinomas the relatively abundant and well differentiated stroma usually 

 contains an appreciable mast-cell content (Baumer, 1896; Harris, 1900; 

 Williams, 1900; Clowes and Owen, 1904) whereas in more anaplastic tumours 

 the stromal mast cells are few and poor in granules (Regaud and Lacassagne, 

 1922; Higuchi, 1930; Holmgren, 1946). 



Consideration of the foregoing data suggests that the accumulation of 

 mast cells around the growing edge of tumours and the presence of mast cells 

 within the stroma of slowly growing neoplasms both reflect changes in the 



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