A 77-years-old patient complains of inability to urinate and bursting pain above his pubis. Acute onset of his condition occurred 12 hours ago. Objectively: overfilled urinary bladder can be palpated above the pubis. On rectal examination: prostate is enlarged, dense-elastic, with clear margins and no nodules. Interlobar sulcus is pronounced. US examination: prostate volume is 120 cm3, it protrudes into urinary bladder cavity, parenchyma is homogeneous. Prostate specific antigen is 5 ng/ml. What disease is the most likely to cause acute urinary retention?