Cystic Prostate Lesions

Sonia Gaur MD 1, Chandy Ellimoottil MD MS 2, Prasad R. Shankar MD 1, 3

1 Michigan Medicine, Department of Radiology 2 MichiganUniversity Medicine, Departmentof Michigan of Urology 3 MichiganDepartment Radiology Qualityof Radiology Collaborative University of Michigan Case History • 70-year-old male, presenting to urology clinic with lower urinary tract symptoms: – Decreased spontaneous voiding, – Intermittent catheterization every 4 hours – Rectal urgency

• Cystoscopy: large extrinsic structure compressing bladder base

• Prostate MRI performed for further assessment Multiparametric MRI T2W

Sagittal T2W

ADC DWI Multiparametric MRI T2W

Pre-Contrast Imaging Findings

• 5.2 cm cystic mass within expected location of prostate transition zone, abutting the bladder base

• No residual transition zone Sagittal T2W identified ADC DWI • Vas deferens and seminal vesicles distinct from this structure

• No associated restricted diffusion Multiparametric MRI – Post-Contrast images

T2W DCE pre-contrast DCE post-contrast Multiparametric MRI – Post-Contrast images

T2W DCE pre-contrast DCE post-contrast

Post-Contrast Findings

• Enhancing tissue at the right posterior margin of this structure measuring 1.8 x 0.7 cm (A)

• The cystic mass is located anterior to expected location of prostatic utricle cyst

• Causes leftward displacement of junction of membranous and penile urethra What could this possibly be?

A DDx of cystic prostate lesions… Benign Intraprostatic Cysts • Typically midline, posterior to the urethra • 0.8-1.0 cm, pear shape • Communicates with prostatic urethra Prostatic Utricle Cyst • Associated with genitourinary anomalies - hypospadias, cryptorchidism, renal agenesis • Can become infected or have hemorrhage – imaging will resemble abscess/ cystic tumor

Shebel HM, Farg HM, Kolokythas O, El-Diasty T. Cysts of the Lower Male Genitourinary Tract: Embryologic and Anatomic Considerations and Differential Diagnosis. Radiographics, 2013 Nghiem HT, Kellman GM, Sandberg SA, Craig BM. Cystic lesions of the prostate. Radiographics 1990; 10:635-650 Benign Intraprostatic Cysts

• Typically midline, posterior to the urethra • 0.8-1.0 cm, pear shape Prostatic Utricle Cyst • Communicates with prostatic urethra • Associated with genitourinary anomalies - hypospadias, cryptorchidism, renal agenesis • Can become infected or have hemorrhage – imaging will resemble abscess/ cystic tumor

• Early adulthood, manifest with UTI, urinary retention • At aspiration : contain calculi Mullerian Duct Cyst • Teardrop shaped midline cysts extending above the prostate (can see at level of seminal vesicles)

• Early adulthood, manifest with UTI, urinary retention • At aspiration : contain calculi Mullerian Duct Cystic • Teardrop shaped midline cysts extending above the prostate (can see at level of seminal vesicles)

• Common, accounts for most prostatic cystic lesions Cystic Degeneration • Located in transition zone, among BPH nodules of BPH • Usually presents as urinary obstruction secondary to BPH

• Presents as a large pelvic mass, compressing adjacent organs but with Multilocular Prostatic no clear aggressive features Cystadenoma (benign) • Often identified retroperitoneal • Obstructive voiding symptoms

Multilocular Prostatic • Presents as a large pelvic mass, compressing adjacent organs but with no clear aggressive features Cystadenoma • Often identified retroperitoneal (benign) • Obstructive voiding symptoms

• Wall nodularity, with solid wall components representing the neoplasm • Tumors that can exhibit cystic components Cystic Carcinoma of Papillary cyst adenocarcinoma the Prostate (malignant) Combined transitional cell carcinoma • Both acinar adenocarcinomas and ductal carcinomas have been reported as appearing cystic

• Anterior to- and displaces urethra, as opposed to communicating with the urethra – Making a prostatic utricle cyst unlikely

• Did not extend beyond prostate base, seminal vesicles preserved.

• Could be a benign finding, however concerning for cystic neoplasm, given solid nodular enhancing region along right posterolateral wall

• Favored to represent a cystic neoplasm arising from a Mullerian remnant Back to Present Case..

• Presented at multidisciplinary tumor board: – Biopsy deferred due to increased risk of seeding if potentially neoplastic – Unlikely to alter definitive management • ** Prior biopsy attempts at OSH reportedly unsuccessful

• Recommended for simple prostatectomy

• Shared decision making: Patient considering management options currently Teaching Points • The differential for an intraprostatic cyst is broad, however differentiation on imaging is possible based on location of cyst, size, and characteristics

• Wall nodularity is more suspicious for malignancy, and can show characteristic MRI findings of T2 hypointensity, restricted diffusion, and hyperenhancement

• The risk of malignancy and impact on management should be considered when evaluating these patients for biopsy References 1. Shebel HM, Farg HM, Kolokythas O, El-Diasty T. Cysts of the lower male genitourinary tract: embryologic and anatomic considerations and differential diagnosis. Radiographics 2013; 33:1125-1143 2. Nghiem HT, Kellman GM, Sandberg SA, Craig BM. Cystic lesions of the prostate. Radiographics 1990; 10:635-650 3. Nakamura Y, Shida D, Shibayama T, et al. Giant multilocular prostatic cystadenoma. World J Surg Oncol 2019; 17:42 4. Humphrey PA. Variants of acinar adenocarcinoma of the prostate mimicking benign conditions. Mod Pathol 2018; 31:S64-70 5. Yadav SS, Baghel P, Tomar V, Agarwal N, Dhakad D. Prostatic Ductal Adenocarcinoma-A Rare Entity With Radiological Dilemma Demanding Endoscopic Biopsy. Urology 2017; 108:e1-e2 Thank You [email protected]

@UmichRadiology @SoniaSGaur