Radiologic-pathologic correlation of prostatic cancer extracapsular extension (ECE)

Abstract

Recent advancements on nerve-sparing robotic prostatectomy allow fewer side effects such as urinary incontinence and sexual dysfunction. To perform such techniques, it is essential for the surgeon to know if the neurovascular bundle is involved. Despite being the gold-standard imaging method for Prostate Cancer (PCa) staging, Magnetic Resonance Imaging (MRI) lacks high specificity for detecting extracapsular extension (ECE). Therefore, it is essential to understand the pathologic aspects of ECE to better evaluate the MRI findings of PCa. We reviewed the normal MRI appearance of the prostate gland and the periprostatic space and correlated them to prostatectomy specimens. The different findings of ECE and neurovascular bundle invasion are exemplified with images of both MRI and histologic specimens.

Keywords: Extracapsular extension; Magnetic resonance imaging; Prostate; Prostatic cancer; Radiologic-pathologic correlation.

Fig. 1

Timeline showing the different physiologic features of the normal prostate on T2-weighted MR images. Younger patients have a dominant PZ, which is homogeneous and shows low signal-intensity. In middle-aged men, non-nodular T2-hypointense bands can appear in the PZ, in relation with prostatitis (grey arrow) and the TZ becomes larger. In older patients, the TZ becomes dominant, with multiple well-delineated nodules, corresponding to benign prostatic hyperplasia (blue arrows). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 2

Radio-pathological correlation of normal prostatic anatomy. T2-weighted image MR image demonstrating the TZ with low signal intensity, surrounded by the PZ with high signal intensity. The prostate is limited by a pseudocapsule, seen as a thin low signal intensity rim (black arrows). Beyond its boundaries lies the periprostatic space (dashed line), containing fat (depicted as high-signal intensity), nerves, and vessels (tubular structures with low signal intensity). The correspondent histological specimen illustrates the prostatic capsule (red line) and the periprostatic space, containing fat, nerves, and vessels (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 3

Findings that suggest prostatic cancer extra-capsular extension (ECE) on MRI. These findings can be divided into early and late, as the tumoral invasion progresses from microscopic ECE to perceptible macroscopic tumoral deposits. Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 4

Schematic representation of the findings that advocate prostatic cancer extra-capsular extension (ECE) on axial T2-weighted images of MRI from different patients with prostatic cancer. Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 5

Representation of the findings of neurovascular bundle invasion (NVBI) on T2-weighted images of MRI from different patients with prostatic cancer. Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 6

Modified Gleason grading schematic diagram based on 2015 modified ISUP Gleason schematic diagram (a). Histologic definition of the International Society of Urological Pathology (ISUP) grading system (b)

Fig. 7

Histological analysis from a prostatectomy specimen shows the pseudocapsule formed by organized layers of condensed smooth muscle. Beyond it, the periprostatic tissue is seen, mainly constituted by adipocytes (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 8

T2-WI MR image shows a low signal intensity right lesion (blue arrow) that shows no capsular contact or other signs of suspicious extracapsular extension. The correspondent histological analysis confirms the tumor (dark arrow) with no contact with the capsule (red line). (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C -18,805) EPOS™ poster presented at ECR 2022

Fig. 9

T2-WI MR image shows a low signal intensity right peripheral lesion with narrow contact with the capsule (blue arrows), with no bulging, only irregularity of the capsular contour. The correspondent histological analysis reveals narrow tumoral capsular contact (tumor margin lined in blue), measuring 2.6 mm in extension. The capsule is lined in red. (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 10

T2-WI MR image shows a low signal intensity left peripheral lesion with broad contact with the capsule (blue arrows) but with no budging, only irregularity of the capsular contour. The correspondent histological analysis reveals the tumor (lined in blue) contacting the prostatic capsule (red line). This contact has 26 mm in extension, but there is no extracapsular extension (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 11

T2-WI MR images with zoom out and in reveal a low signal intensity left lesion that shows broad contact with the capsule (dashed blue line). The correspondent histological analysis reveals tumor (blue line) with extensive tumoral capsular contact of more than 38 mm (dashed red line). There are also positive surgical margins located between the two green lines and marked with a white arrow (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 12

T2-WI MR image reveals a low-signal intensity peripheral lesion that shows broad contact with the capsule, with bulging and ECE (blue arrow). The correspondent histological analysis reveals small tumoral foci (one marked with an arrow) beyond the prostatic capsule (red line), corresponding to extraprostatic extension (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022

Fig. 13

T2-WI MR image reveals a low signal intensity peripheral lesion, at the base, that contacts the prostate capsule (broad contact) associated with irregular prostatic contour and periprostatic fat infiltration (blue arrow). The correspondent histological analysis reveals tumoral foci (arrows) beyond the expected prostatic capsule, corresponding to extraprostatic extension (Hematoxylin and Eosin (H&E)). Reprinted with permission from Flor-de-Lima B, Freire G, Lopes A, et al. (2022) Radiologic-pathologic correlation of prostatic cancer extra-capsular extension (ECE) (C-18805) EPOS™ poster presented at ECR 2022