Epididymal leiomyoma

Epididymal leiomyomas (fibrous pseudotumours) are uncommon smooth muscle tumours that do not have malignant potential. Their imaging features are not specific and, if small, it may be a difficult prospective diagnosis on imaging. They are usually encountered in a differential for epididymal/paratesticular masses and are the second most common epididymal mass, after adenomatoid tumours.

Clinical presentation

• slowly-growing nontender scrotal mass
• more common at age 40 and older 

Radiographic features

Ultrasound

• solid, well circumscribed usually hypoechoic mass centred in the epididymis
  • may also be cystic or calcified ³
• 1-4 cm in size

MRI

• homogeneous low signal intensity on T1- and T2-weighted images

Differential diagnosis

• adenomatoid tumour
  • more common, similar appearance
• sperm granuolma
• sarcoidosis affecting the epididymis

See also

• epididymal lesions
• paratesticular lesions