Prostate cancer - staging

Biparametric MRI of the prostate bpMRI

Findings:

Quality: some patient movement between sequences, does not impair diagnostic confidence

Prostate size: 43 x 35 x 47 mm (CC x AP x ML) ≈37 mL, PSA density ~0.33 ng/mL²

Hemorrhage: small bleeding in the left posterior transition zone

Peripheral zone (PZ): focal findings as below, beyond that mild hypointensities

Focal lesion #1:

• circumscribed T2 homogenous moderate hypointense focus (18 x 10 x 15 mm) of the left midglandular, anterior and apical, peripheral zone (PZa) with diffusion restriction and indistinct margin of the pseudocapsule
• visible on axial images and sagittal images

Focal lesion #2:

• circumscribed T2 homogenous moderate hypointense focus (25 x 10 x 15 mm) of the left posterolateral base with a capsular breach, and diffusion restriction
• adjacent asymmetric moderate hypointense signal intensity in the left central zone (CZ) surrounding the left ejaculatory duct and extending into the left seminal vesicle
• visible on axial, sagittal and coronal images

Focal lesion #3:

• thin, circumscribed T2 homogenous moderate hypointense focus (8 x 2 x 8 mm) of the midglandular peripheral zone (PZpl) adjacent to the capsule
• visible on axial images and coronal images

Transition zone (TZ): moderate heterogeneity, multiple BPH nodules, indistinct pseudocapsule left mid gland anterior and left posterior transition zone

Prostate margin: lesion #2 with capsular contact and breach

Neurovascular bundles: probably involved

Seminal vesicles: left seminal vesicle hypointense with diffusion restriction suggestive of seminal vesicle invasion

Lymph nodes: round lymph node (6 mm size, fatty hilum) in the left perirectal fat tissue, oval external iliac lymph nodes (up to 5 mm size, fatty hilum, smooth margins)

Pelvic bones: no signs of bony metastasis

Impression:

Multifocal prostate cancer with lesions in the left anterior peripheral zone and with involvement of the pseudocapsule and in the posterior mid gland and base with probable infiltration of the left central zone.

There is a possible small lesion of the right midglandular, posterolateral peripheral zone.

There are signs of extraprostatic extension at the posterolateral base and signs of left seminal vesicle invasion.

MRI putative stage: cT3bNxMx

Key images:

Focal lesion #1:

T2 moderately hypointense focus with diffusion restriction in the left mid gland (red arrow). There is an indistinct margin of the pseudocapsule (blue arrowhead).

Focal lesion #2:

T2 moderately hypointense focus with diffusion restriction and capsular breach (blue arrow) in the left base of the prostate. Asymmetric T2 moderately hypointense signal intensity in the left central zone (CZ) involving the left ejaculatory duct and extending into the left seminal vesicle (green arrowhead).

Focal lesion #3:

Thin in T2 hypointense lesion with diffusion restriction adjacent to the capsule of the right peripheral posteromedial zone (orange arrow).

Seminal vesicles:

The left seminal vesicle is asymmetrically thickened and hypointense in T2 with focal low signal in ADC suggestive of left seminal vesicle invasion (green arrows).

Findings illustrated on a map.

Biopsy results:

Histology of the US-guided systematic biopsy 4 months before the MRI showed an acinar adenocarcinoma (modified Gleason score 4+4=8, high grade within one core and 3+4=7a low grade within two cores)  of the left mid gland and base and a low-grade acinar adenocarcinoma (modified Gleason score 3+3=6) within one core taken from the right lateral base. The 8 remaining biopsy cores were negative.

The results of the systematic biopsy are illustrated.