(4) They infect adjacent lymph glands.
(5) They recur even after complete removal.
(6) They give metastasis; that is, they become disseminated in different organs.
(7) Their presence develops a progressive emaciation.
BENIGN TUMORS.
(1) These in and of themselves do not tend to produce death.
(2) As the cellular element is not liable to predominate, they grow slowly.
(3) They are encapsulated, and when diffuse do not infiltrate surrounding tissues.
(4) They do not infect adjacent lymph glands.
(5) They do not recur after complete removal.