Spontaneous regression of primary malignant lymphoma of the prostate.

We herein report a case of primary lymphoma of the prostate, which arose in an 85-year-old male with dysuria. CT and MRI examinations demonstrated a large mass in the prostate. A transrectal ultrasound-guided biopsy of the prostate was performed. The histological examination showed diffuse large B-cell lymphoma. The large lesion in the prostate showed spontaneous regression. Spontaneous regression of primary lymphoma of the prostate has not been reported previously. The spontaneous regression of primary lymphoma of the prostate observed in this patient suggests that observation may represent a viable treatment option following a biopsy that has provided a histopathological diagnosis.