MAST CELLS IN PATHOLOGICAL CONDITIONS 



The second tumour, a luteoma, contained even more mast cells than the 

 splenic tumour; here again the mast cells were chiefly associated with the con- 

 nective tissue stroma although (p. 616) 'transplantable luteomas characteristi- 

 cally rich in mast cells were relatively poor in connective tissue'. In addition, 

 some of the luteoma cells displayed a diffuse metachromasia of their cytoplasm. 



In contrast to both the splenic tumour and the luteoma was granulosa cell 

 tumour which contained no mast cells though they were often present in the 

 peritumoral tissues. Thus, whatever may be the reason for the high mast-cell 

 content of the splenic tumour and the luteoma it cannot be explained simply 

 on the presence or absence of stroma, despite the fact that mast cells, when 

 present, tended to be related to the connective tissues. It seems that certain 

 tumours are capable of stimulating the development of mast cells though the 

 precise reasons for this are not clear. 



3. Tumours composed of mast cells. Rarely a tumour is discovered 

 which is itself composed of mast cells. Among the most striking examples of 

 local aggregations of mast cells in pathological states are the skin lesions of 

 urticaria pigmentosa, discovered by Nettleship (1869) and beautifully described 

 in his book by Unna (1896). The skin manifestation of urticaria pigmentosa 

 consists of a dense collection of mast cells distending the papillary body and 

 causing thinning and elevation of the overlying epithelium, the prickle cells of 

 which are pigmented. The mast cells extend into the dermis as columns of 

 cells separated by blood vessels and collagen: very occasionally the regional 

 nodes are enlarged and contain mast cells. On irritating a lesion the papule 

 swells and may even form a blister localized to the pigmented area while the 

 surrounding skin shows more or less erythema. Typically the lesions are small 

 and multiple and tend to disappear spontaneously about the time of puberty, 

 although occasionally the disease makes its first appearance in adult life. 

 Clearly, this is not a malignant tumour in the accepted sense, though it may 

 well belong to the group of reticuloses (Cazal,1942; Sagher, 1956; Marshall 

 etal, 1957; Nickel, 1957; Remy, 1957). 



So far as the writer is aware only one case of true mast-cell tumour in man 

 has been recorded (Hissard, Moncourier and Jacquet, 1950a). A forty-one- 

 year-old male developed numerous partly fixed and ulcerating skin tumours 

 over the abdomen and buttocks; both liver and spleen were palpable. Biopsy 

 of a skin lesion showed it to consist almost entirely of mast cells and blood 

 vessels. The blood picture was normal except after splenic puncture or the 

 injection of adrenaline when mast cells temporarily entered the circulation. 

 In a more detailed account of the histology of this case, Hissard, Moncourier 

 and Jacquet (19506) describe the origin of the tumour mast cells from dermal 

 precursors and believe that the cells migrate towards the epithelium where they 

 undergo lysis. 



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