Prostate cancer - staging

Case contributed by Dr Joachim Feger

Presentation

Prostate cancer - radiation therapy planning. Prostate specific antigen (PSA): 7.7 ng/mL.

Patient Data

Age: 65 years
Gender: Male
MRI

mpMRI

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.

Hemorrhage:  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 images (ima 11-19), sagittal images (ima 3-9)
  • 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 seen

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

Annotated image

Key findings:

In T2 moderate hypointense left posteromedial and posterolateral peripheral zone with diffusion restriction and broad capsular contact and irregularity (red arrows).

Indistinct margin of the pseudocapsule (green arrowhead).

Tumor extension along the ejaculatory ducts into the seminal vesicles above the base of the prostate (blue arrowheads).

Findings from the MRI of the prostate are illustrated on a map.

Biopsy results:

Histology of the US-guided systematic biopsy 4 months prior to the MRI showed a high-grade acinar adenocarcinoma (modified Gleason score 4+3=7b within five cores and 3+4=7a within one core)  of the left lobe and a low-grade acinar adenocarcinoma (modified Gleason score 3+3=6) within one core taken from the right posteromedial midgland. The 5 remaining cores were negative.

The results of the systematic biopsy are illustrated.

Case Discussion

This case shows an already histologically proven prostate cancer.

Histology of the systematic biopsy taken 4 months earlier showed low-grade acinar adenocarcinoma (modified Gleason score 3+3=6) within one core taken from the right medial midgland and intermediate and high-grade acinar adenocarcinoma (modified Gleason score 4+3=7b, high grade) in the samples from the left lobe. None of the samples showed perineural invasion or capsular infiltration.

MRI was done for radiation therapy planning and staging purposes and suggests extraprostatic extension due to the broad capsular contact irregular contour and the capsular bulge.

There are signs of seminal vesicle invasion with extra-glandular tumor extension along the ejaculatory ducts above the base of the prostate.

The patient received intensity-modulated radiotherapy.

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Case information

rID: 73245
Published: 15th Jan 2020
Last edited: 26th Dec 2020
Inclusion in quiz mode: Included