Lymphocytes of the Lymphocytic Leukemias 159 



2. In general, leukemic lymphocytes that are morphologically similar to 

 cells in some stage of normal lymphocytogenesis are more likely to be widely 

 and diffusely disseminated with the clinical, hematologic, and pathologic 

 features ol leukemia than are tumors whose cells have abnormal nuclear 

 or cytoplasmic deviations. The latter are more likely to be cases of lympho- 

 sarcoma."' 



Exceptions: In numerous instances tumors with nuclear and cytoplasmic 

 abnormalities not found in normal tissues may have the manifestations of a 

 diffuse disease indicative of leukemia. Similarly, it is not always possible to 

 detect morphologic abnormalities in cells of tumors with restricted growth. 



It should be noted that the nuclear and cytoplasmic characteristics of the 

 cells are studied to best advantage in smear or imprint preparations''' n 

 while the general architectural and topographic features of nodal structure 

 are better demonstrated in sections. Study of a lymph node is not complete 

 unless both smear (or imprint) and sectioned material have been examined. 



3. In seneral, cases with relativelv mature cells in the blood and tissues 

 are more likely to be chronic , while immature cells usually predominate in 

 the more acute forms. 



A parallel situation occurs in all tumors. The procedure of "grading" 

 tumors depends on determining the proportion of the more or less mature 

 (differentiated) and immature (undifferentiated) cell types. 



Exceptions: The degree of malignancy as indicated by the clinical course 

 is not always that expected from study of the cells. Cases with relatively 

 mature cells may progress rapidly or have acute exacerbations; cases with 

 immature cells (lymphoblasts) may have courses longer than anticipated. 



4. Tumors with a follicular histologic pattern (follicular lymphoblastoma, 

 giant follicle lymphoblastoma) are likely to have a prolonged course. If the 

 presence of a follicular pattern may be taken as an indication of maturation, 

 this again is in conformity with the general statement that maturity is usually 

 accompanied by a longer course. 



Exceptions: The subsequent occurrence of obvious clinical malignancy, 

 which usually occurs only after a long interval, is sometimes rapid in its 

 development. 



5. Tumors composed of cells larger than a lymphocyte and with clearer 

 nuclei and cell bodies are often referred to as reticulum cell tumors without 

 further study of cell details. Size and cell clarity alone are not enough for 

 the identification of reticulum cells (histiocytes). The sarcomatous tumors 

 that have been described under this name comprise a heterogeneous group' 5 



