THE PATHOLOGICAL ANATOMY 



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provide a working basis, these growths may be divided arbitrarily and 

 for convenience, as follows : 



(growing 

 involuting 

 resting 



fgrowing 

 Intermediate adenoma < involuting 



[resting 

 [growing 



Fetal adenoma -j involuting 

 [resting 



Each of these groups has a growing, involuting and resting or colloid 

 stage. Ribbert (&), Virchow (a-). 



Simple Adenomas. These masses are more frequently seen in 

 the so-called nodular goiters (struma nodosa), and make up a large pro- 



Fig. 22. Simple adenoma from endemic goiter in man, showing capsule, slight 

 active hyperplasia of well differentiated thyroid tissues. (After Marine, J. Med. Re- 

 search, 1913: 27.) 



portion of the "struma knotchen" which occur commonly in the goiters 

 of late childhood and puberty in endemic goiter districts. They are 

 always multiple rounded masses of varying size and in their growing 

 phases are integral parts of the general goiter, but in their late stages 

 may become more distinct and isolated through secondary changes. The 

 true capsule if present, is rudimentary, while in their late stages they 

 have a well-defined false capsule derived from the stretched and atrophic 

 non-tumor tissue. Histologically as regards epithelium, colloid, alveoli, 



