We report the case of a 78-year-old man with recent diagnosis of Kahler disease and a non-tender swollen left hemiscrotum. Ultrasound findings showed an intratesticular, hypervascular hypoechoic lesion. MRI imaging demonstrated general appearance of a malignant lesion. Specific characteristics however, could not be withheld on MRI. Orchidectomy was performed and plasmacytoma was demonstrated at pathological examination. Although plasmacytoma of the testis is extremely rare, it should be included in the differential diagnosis taking into account the ultrasound and MRI appearances, especially in elderly patients with known Kahler disease.