A rare case of malignant non-Hodgkin lymphoma of the adrenal gland in a 59-year-old male is reported. This patient, completely healthy, observed for a routine check after a laparoscopic cholecystectomy performed one year before, underwent an explorative laparatomy for getting information about a retroperitoneal mass, ultrasound scan observed. A CT guided needle biopsy was inconclusive to clarify this rare haematological diagnosis.