histamine: pathological tissues 



The third example of a mast-cell tumour in a cat occurred in a three-year-old 

 castrated male which developed numerous skin nodules over a period of about 

 two months. At post-mortem examination it was also discovered that some 

 of the lymph nodes draining the skin were enlarged and that there was consider- 

 able enlargement of the spleen, as in the two previous cases. Material for 

 histamine assay was placed in trichloracetic acid within two hours of death. 

 No tissue was obtained for heparin estimation. The histamine values are shown 

 in Table XII. Histological examination of corresponding material confirmed 

 the very close parallelism between the mast-cell contents of the various tissues 

 on the one hand and the histamine values on the other. Here, as in the dog, it 

 will be noted that the spleen was the chief site of secondary involvement in all 

 three cases of mastocytoma in cats. 



Table XII 



Histamine values in tissues obtained two hours 



post-mortem from a three-year-old male cat 



with multiple mastocytomas of the skin 



Cattle. Having assayed histamine and heparin in urticaria pigmentosa in 

 man, and in mastocytomas from dogs and cats, we were exceedingly fortunate 

 in being able also to examine repeatedly material from a cow with multiple 

 mastocytomas of the skin (Head et ah 1953; 1958). Such tumours are very 

 rare indeed (Head, 1953). 



In the autumn of 1954 a six-months'-old shorthorn heifer developed multiple 

 small skin nodules which bled easily on slight trauma, though there was no 

 impairment of general condition. A biopsy specimen sent from Leeds to 

 Edinburgh and examined by Mr. K. W. Head was diagnosed as a mast-cell 

 tumour and, accordingly, bottles of the appropriate fluids for histamine and 

 heparin assay were forwarded to the practitioner who kindly removed and 

 weighed further nodules for which the following values were obtained : histamine 

 180 [xg./g., heparin 14 i.u./g. Through the good offices of the Royal (Dick) 

 School of Veterinary Studies, the cow (now in calf) was purchased and brought 

 to Edinburgh where it gave birth to a normal bull calf in May 1955. 



During pregnancy the animal remained in excellent condition, developed 

 the usual long winter coat (except immediately around the nodules) and shed 

 this coat normally in the spring. Meanwhile, no fresh nodules had appeared 

 and the ulceration in many of the existing nodules had subsided. It will be 



89 



