What is the percentage of prostate cancers that originate in the peripheral zone?
Approximately 70-75% of prostate cancers originate in the peripheral zone.
Are there imaging signs of extraprostatic extension?
Yes, there is a broad capsular contact (>20 mm) there is an irregular contour and a bulge. So there is a high probability of extracapsular extension.
What are the signs of seminal vesicle invasion on MRI?
Low signal intensity on T2 and ADC without corresponding high signal on T1, asymmetric wall thickening or mass.
Are there signs of seminal vesicle invasion in this MRI?
There are signs of tumour extension along the ejaculatory ducts into the seminal vesicles above the base of the prostate. There are no metachronous deposits.
Quality: mild geometric distortion on DWI, does not compromise diagnostic confidence
Prostate size: 48 x 40 x 55 mm (CC x AP x ML) ≈55 mL, PSA density ~0.14 ng/mL2.
Haemorrhage: none
Peripheral zone (PZ): focal finding on the left as below, beyond that heterogeneous signal intensity
Focal lesion #1:
- location: left lobe, peripheral zone – apical to basal mainly posterolateral (anterior to posteromedial), visible on axial and sagittal images
- lesion size: 25 x 15 x 25 mm
- T2w: circumscribed, homogenous moderate hypointense with an indistinct margin of the pseudocapsule
- DWI: markedly hyperintense on DWI (b1000 and b1400) and markedly hypointense on ADC
- DCE: focal early enhancement - positive
Transition zone (TZ): moderate heterogeneity, multiple BPH nodules
Prostate margin: lesion #1 with broad capsular contact (>20 mm), irregular contour and bulge
Neurovascular bundles: probably involved
Seminal vesicles: there are signs of extension along the ejaculatory ducts into the seminal vesicles above the base of the prostate
Lymph nodes: no enlarged or suspicious lymph nodes
Pelvic bones: no signs of bony metastasis
Impression:
Histologically proven prostate cancer, visible in the left peripheral zone (apical to basal, posteromedial to anterior) with broad capsular contact and capsular bulge.
MRI putative stage: cT3bN0Mx