Malignant lymphoma of bone in children

From 1960 to 1985 at the Royal Children's Hospital, Melbourne, seven cases of malignant lymphoma of bone (MLB) were identified in children younger than 16 years of age. Over the same period there were 88 cases of Ewing's sarcoma (ES), which illustrates the rarity of MLB. All cases were staged and treated according to protocols current at the time, namely, systemic chemotherapy with radiotherapy to the primary lesions. One child received radiotherapy alone as chemotherapy was not then available (1963). The disease-free five-year survival rate in our small series is 57%, which compares favorably with the 62% that we have calculated from survival data available from 26 previously reported cases of MLB in children and better than the 35% to 50% quoted in adult series of MLB. The main problem in differential diagnosis is distinguishing MLB from ES. A positive diagnosis of MLB rather than ES can be made, however, by observation of the characteristic reticulin staining pattern, the absence of cytoplasmic glycogen, and the ultrastructure.