In making a bimanual examination of the kidney or of a uterine or ovarian tumor it is often difficult to determine with great precision the extreme boundaries of the growth or of the misplaced organ. There is often a doubtful zone, around the more central manifestly resistant part of the tumor, where it shades off into the surrounding tissues.
The result attained by the customary methods of palpation may be said to yield the umbra or the more definitely resisting portion, while outside of the umbra lies a zone which we may call the penumbra or the doubtful area. Now, if I could only so palpate as to recognize the changes of consistency between the penumbra and its enveloping tissues I would then be able to enlarge the boundaries of the tumor or organ in question and so to reach more definite results.
A bimanual palpation concerns itself with these