Lymphomas: Basic points that radiologists should know.

Lymphomas affect the lymphoid system and may be expressed in a variety of ways and behave in different fashions. The polymorphism of their expression, depending on the organ involved, their variable aggressiveness and their relative rarity compared with primary or secondary diseases sometimes makes it difficult to diagnose them from imaging. Knowledge of predisposing factors and radiological signs should help suggest this diagnosis and thus lead to biopsy samples being taken to confirm it.