Structure of Lymphocytic Series of Cells in Relation to Disease 265 



two conditions. The lipid presents in a globular inclusion in Niemann- 

 Pick's disease, but it is noteworthy that the inclusions in Gaucher's disease 

 are in the form of colorless spindles throwing the unaffected basophilic 

 cytoplasmic areas into blue nbrillar-like arrangements. Cavanagh" has re- 

 cently summarized the available knowledge of the chemistry, cytology, 

 and histogenesis of these and related conditions. In this connection, imprint 

 studies of the affected cells in Letterer-Siwe's disease and eosinophilic granu- 

 loma, conditions somewhat related to Hand-Schuller-Christian disease, 

 should afford greater insight into the true nature of these conditions. 



Fig. 19-3. Phagocytic reticulum cell, the lipid histiocyte of Hand- 

 Schuller-Christian disease. Bone marrow. Leishman stain, (x 1100) 



We have imprinted a single case of each Letterer-Siwe's disease and eosino- 

 philic granuloma of bone. In the former, rather uniform mononuclear, in- 

 active-appearing histiocytes apparently of reticulum cell origin with pale, 

 homogeneous cell bodies were found in company with giant, polymorpho- 

 nuclear or multinucleated pleomorphic malignant-appearing reticulum cells. 

 In the latter, eosinophilic granuloma of bone, again uniform, mononuclear, 

 inactive-appearing histiocytes very similar to those seen in Letterer-Siwe's 

 disease were numerous, but the malignant-appearing giant reticulum cells 

 were not present and in their place were numerous eosinophilic granulo- 

 cytes. 



Latest member of this group with accumulation of characteristic sickle- 

 form PAS-positive cytoplasmic particles in the reticulum cells, again in 



