Focal Lesion in Prostate



Focal Lesion in Prostate


Winnie C.W. Chu, MBChB, FRCR

Michael P. Federle, MD, FACR



DIFFERENTIAL DIAGNOSIS


Common



  • Benign Prostatic Hyperplasia (BPH), Hyperplastic Nodules


  • BPH, Cystic Degeneration


  • Prostatic Calcification


  • Prostatic Carcinoma (CA)


  • Retention Cyst


  • Utricle Cyst


  • Müllerian Duct Cyst


Less Common



  • Prostatitis, Focal


  • Prostatic Abscess


  • Metastases and Lymphoma, Prostate


  • Ejaculatory Duct Cyst or Diverticulum


  • Seminal Vesicle Cyst or Ductal Ectasia


  • Vas Deferens Cyst


Rare but Important



  • Prostatic CA, Cystic


  • Multilocular Prostatic Cystadenoma


  • Hydatid Cyst


  • Prostatic Urethral Diverticulum


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Focal lesion might be discovered by palpation (digital rectal exam) as incidental finding or part of screening exam


  • Or in patient with symptoms, signs, or abnormal laboratory evaluation



    • Fever, pain, dysuria, hemospermia, painful ejaculation


    • ↑ PSA (prostate specific antigen)


  • Location of cystic lesion helps in diagnosis



    • EDC and utricle cysts normally communicate with the urethra; müllerian duct cysts rarely do


Helpful Clues for Common Diagnoses



  • Benign Prostatic Hyperplasia (BPH), Hyperplastic Nodules



    • Hyperechoic nodules in an enlarged gland


    • May undergo cystic degeneration


    • Located in the transitional and periurethral zones


    • May be confused with prostatic carcinoma


  • BPH, Cystic Degeneration



    • Typically located in transitional zone


    • Arises within hyperplastic nodules


  • Prostatic Calcification



    • Common feature of chronic prostatitis


    • Caused by calcium precipitation inside acini whose ducts are obstructed by inflammation


    • Intraglandular or periurethral


    • In young patients, calcifications are usually periurethral


  • Prostatic Carcinoma (CA)



    • > 90% are hypoechoic (less commonly iso-or hyperechoic)


    • About 70% occur in peripheral zone


    • 30% of tumors not evident on ultrasound



      • Indistinguishable from hyperplastic nodules in the transitional zone


    • Extracapsular extension common in advanced disease


  • Retention Cyst



    • Results from obstructed glandular acinus


    • Unilocular with smooth walls


    • Location variable; size ≈ 1 to 2 cm


    • May be indistinguishable from BPH


  • Utricle Cyst



    • Cystic dilatation of prostatic utricle, acquired or congenital



      • Congenital results from abnormality in regression of müllerian duct system


    • Intraprostatic; midline, arises from verumontanum


    • Usually small; tubular or pear-shaped


    • Normally communicates with the urethra


    • Associated with hypospadias, undescended testes, and unilateral renal agenesis


  • Müllerian Duct Cyst



    • Originates from remnant of müllerian duct


    • Extraprostatic; midline


    • Usually large; extends above prostatic base


    • Oval/teardrop shaped; rarely communicates with the urethra


    • Though rare, may contain calculi


    • Differentiation from utricle cyst is difficult


Helpful Clues for Less Common Diagnoses



  • Prostatitis, Focal



    • Clinical: Tender and warm to palpation


    • Acute: Size may be normal but often enlarged; ill-defined margin; hypoechoic areas with ↑ vascularity


    • Chronic: Normal-sized gland; heterogeneous echo pattern ± calculi


  • Prostatic Abscess



    • As a complication of prostatitis



    • One/multiple prostatic cystic lesions with internal debris ± septae ± gas


  • Metastases and Lymphoma, Prostate



    • Metastases most frequent from direct extension from carcinoma of rectum, bladder, seminal vesicle


    • Lymphoma: Usually part of disseminated disease


  • Ejaculatory Duct Cyst or Diverticulum


  • Intraprostatic, along ejaculatory duct



    • Paramedian at base, midline at verumontanum


    • Normally communicates with the urethra o Intracystic calculi are common


    • Ejaculatory duct diverticulum is rare


  • Seminal Vesicle Cyst or Ductal Ectasia



    • Variable in size; rarely bilateral


    • Unilocular or multilocular


    • Associated with renal agenesis/dysgenesis


    • Ductal ectasia caused by ejaculatory duct or vas deferens obstruction


  • Vas Deferens Cyst



    • Extraprostatic, superior to the gland


    • Associated with ectopic vas deferens with abnormal vas-ureteral communications


Helpful Clues for Rare Diagnoses



  • Prostatic CA, Cystic



    • Complex cyst contains solid and cystic components


    • Predominantly peripheral in location


    • Extracapsular extension is definitive for malignancy, differentiating it from other cystic lesions


  • Multilocular Prostatic Cystadenoma



    • Rare benign prostatic tumor


    • Can enlarge to cause urinary obstruction


  • Hydatid Cyst



    • Simple or multiloculated with endocysts


    • Egg-shell/cyst wall calcification common


  • Prostatic Urethral Diverticulum


  • Anterior: Commonly due to instrumentation trauma or infection


  • Posterior: Commonly related to rupture of a prostatic abscess


  • May be single or multiple


  • Wide or narrowed neck with smooth or ragged walls


Alternative Differential Approaches

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Aug 2, 2016 | Posted by in GENERAL | Comments Off on Focal Lesion in Prostate
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