Osler delivered a number of lectures on how to diagnose abdominal tumors to a postgraduate class at the Johns Hopkins Hospital in 1893. The comments to this class about abdominal tumors in childhood, cited below, give an idea of Osler's lecture style.
In children, massive tumors of the abdomen are not uncommon, and, as a rule, are either sarcomata of the kidney or of the retro-peritoneal glands. The kidney tumors are the most frequent. Both ultimately produce large, solid growths, which may occupy the greater portion of the abdominal cavity. In the differentiation of these two forms we rarely have any difficulty. Both develop painlessly, and the child may make no complaint whatever; the general health may not be seriously affected, even when the mass has attained a considerable size. Death, indeed, may occur, as in a remarkable case which I have reported of embolism of the heart (the transference of sarcomatous thrombi from the renal vein) , before there were any symptoms to attract attention. Progressive emaciation, with enlargement of the abdomen, usually painless . . . are the prominent characters, which are common, however, to both the renal and the retro-peritoneal growth. The two important points of differentiation are, first, the retro-peritoneal growth is more central in its origin, and, if seen early, it is found to occupy the umbilical region, not extending to the flanks; whereas, in the renal tumor, as in the case before us, the growth is lateral, and fills the entire flank, extending deeply behind.