Melanoma. 



379 



In cattle melanomata are of less frequent occurrence. Metz 

 saw two cases in white animals ; in one the tumor was situated 

 in the dewlap, in the second in the pelvic cavity near the uterus. 

 Hamburger found one tumor of this kind in the diaphragm ; 

 Hoare removed a melanoma weighing fifteen kilograms from the 

 temporal region of a brown ox. Bollinger has recorded the 

 occurrence of a congenital melanoma of the size of a fist in the 

 cranial cavity of a thirty-day-old calf; Wulf, a similar growtk 

 in the subcutaneous tissue of the ankle of a calf. In sheep 

 Worseley has reported a case of melanosarcomatosis involving 



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r^-^-^-^. 







Fig. 110. 

 Microscopic section of sliin of horse infiltrated with melanoma. 



the lumbar region, mammary glands, lungs and liver. In the dog 

 the author has observed a melanoma, springing from the gums, 

 and Bruckmiiller one at the base of the brain. 



Some melanomata have a firm, rather dry appearance ; others 

 are found of soft consistence. The cut surface is uniformly 

 dark, or sepia-brown or slaty ; when handled the fingers are 

 soiled as if with shoe-blacking. 



Microscopically the pigment is found in the form of brown- 

 ish black granules, which are distributed in the fluids of the 



