548 TUMORS. 



tumor in part only or throughout its entire mass. Among these 

 changes I have observed the following : 



(a) Fatty Metamorphosis of the Cancer Epithelia,. This was 

 known to the older pathologists as a yellow reticulum, usually 

 seen in the central portions of the tumor. In the center of the 

 nests in the variety termed epithelioma the epithelia are often 

 transformed into fatty masses the so-called cancer pearls. In 

 scirrhus the fatty metamorphosis may invade a large number of 

 epithelia, and in this way the tumor is robbed of its malignancy, 

 at least to a certain extent. As a change subsequent to fatty 

 metamorphosis, calcareous deposition occurs. This I found in a 

 cancerous growth, the size of a pigeon's-egg, which I extirpated 

 from the subcutaneous tissue of the lateral region of the neck ; it 

 exhibited calcareous depositions throughout all the epithelia to 

 such a degree that it could be cut only after treatment with a 

 chromic acid solution. Obviously, such a metamorphosis renders 

 the tumor innocuous. 



("b) Waxy Metamorphosis. This I have repeatedly observed in 

 cancerous tumors. It transforms both the connective tissue and 

 the epithelia into a shining, homogeneous mass, and, if combined 

 with colloid degeneration, destroys the original structure, so that 

 the latter is recognizable only in some portions which are less 

 changed. Such a condition I have seen in a cancer of the parotid 

 gland. Sometimes shining and concentrically striated so-called 

 amylaceous corpuscles are present in the connective tissue 

 frame, and these may also become the seat of calcareous deposi- 

 tion (the so-called arenoid corpuscles of Virchow). 



(c) Colloid Metamorphosis. It occurs chiefly in cancerous 

 tumors of the alimentary canal and the salivary glands, very 

 rarely in external organs. This change very much lessens the 

 malignancy of the tumor, although a recurrence has in some 

 cases been observed after extirpation. 



(d) Cystic Metamorphosis, which is closely allied to the col- 

 loid change. Both processes are considered in the following 

 article. 



(e) Pigmentary Metamorphosis. This is much rarer in carci- 

 noma than in myeloma, and gives the tumor a brownish or bluish- 

 black color to the naked eye. I have seen but one case of a tumor 

 of this kind j it grew on the right shoulder of a man, and soon 

 re-appeared after extirpation, which indicates that the presence 

 of pigment increases the malignity of cancer, as it does that 

 of myeloma. The recurrent tumor, in its uppermost portions, 



