May Be Caused by

 Common

Benign prostatic hyperplasia

Ectopic kidney

Gestational trophoblastic disease

Intraperitoneal fat

Lymph node enlargement

Lymphoma

Metastasis

Ovarian neoplasm

Prostate carcinoma

Prostatic abscess

Prostatitis

Uterine fibroid

Uterine neoplasm

 Uncommon

Bicornate uterus

Extraperitoneal neoplasm

Ganglioneuroma

Hemangiopericytoma

Lipoma

Liposarcoma

Neuroblastoma

Neurofibroma

Pheochromocytoma

Spindle cell tumor

Teratoma

Uterus didelphys