FIELD E; Tumor Code 



Columns 18, 19, 20, 21, 



22, 23, 24, and 25 



Symbol for 



the fourth unit 



(Column 21) 



Animal tumors 



1 Epithelial tumors (including all tumors derived from glandular tissue, regardless of 



its being endocrine or exocrine gland tissue) 



2 Hemopoietic tumors: tumors of blood and lymph and blood- and lymph-forming tissues 



3 Connective tissue tumors 



4 Miscellaneous tumor tissue types difficult to identify with normal tissues: "round 



cell tumors", "spindle cell tumors", etc. 



5 Muscle tissue tumors 



6 Vascular tissue tumors; endothelial tumors 



7 Nerve tissue tumors and tumors of tissues of the nerve sheath, meninges, etc. 



8 Pigment tissue: melanin-forming-tissue tumors (often related to, or are of, nerve 



tissue origins) 



9 Tumors of mixed tissues including teratomas 

 A Embryonic tissue tumors 



Plant tumors 



J Epidermal tissue tumors (plant) 



K Vascular tissue tumors (plant) 



L Parenchymal tissue tumors (plant) 



M Pigment tissue tumors (plant) 



N Embryonic tissue and mixed tissue tumors (plant) 



The tumors included in this published edition of the CBCC Biology Code are listed according 

 to their tissue origins. Therefore, that list itself includes, in consecutive sequence, the definitions 

 of the above symbols for major tissue types. In addition, by virtue of this arrangement of the tumors, 

 the definitions for symbols of units five and six (see the following paragraphs) are likewise evident in 

 the Tumor Code list. This makes unnecessary a special listing of the tissues and their symbols, 

 either here or in the Code, beyond the introductory outline above. 



The fifth unit represents a subdivision of the major tissue type of tumor. For example, when 

 Symbol 1 (tumors of epithelial tissue) is the fourth unit, Symbol 1 as the fifth unit signifies a tumor 

 of glandular epithelium, while Symbol 2 in the fifth place indicates a tumor of non-glandular epithelium. 



In the same way, the sixth unit represents a subdivision of the tissue type indicated by the 

 fifth. For example, Symbol S — 111 represents tumors of endocrine glandular epithelium, whereas 

 S--112 represents tumors of exocrine glandular epithelium. 



Although the organ-designating part of the tumor symbol (the second and third units) and the 

 tissue-designating part (the fourth, fifth, and sixth units) have independent meanings, it is the 

 combination of the two parts in any given tumor symbol that serves to identify exactly the place of 

 origin of the tumor. Therefore, these five units (2-6), considered in combination , make up a single 

 location-identifying unit, designating the origin of the tumor represented by the symbol. (See the 

 diagram included in Division 1 of this description of the Tumor Code. ) 



5. Part IV of the tumor symbol (seventh unit, Column 24): modifier for distinguishing tumors 

 of identical organ-tissue origins (Parts II and III); causative agents of plant galls 



Since, in general, tumors have been regarded as being characterized by the tissues from which 

 they arose and have been named to reflect this, the tissue designation of Part III (units 4, 5, and 6 

 of the tumor symbol) is frequently adequate for distinguishing a tumor type , or Part III and Part II 

 (the organ origin), as a combination, is adequate. This is not always the case, however, and it is 

 frequently important to be able to distinguish two or more types of tumor which are not distinguished 

 merely by coding the organ and tissue origin. 



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