Presentation
Rising prostate-specific antigen (PSA): 11.2 ng/mL.
Patient Data
Findings:
Quality: mild geometric distortion on DWI, does not compromise diagnostic confidence
Prostate size: 40 x 32 x 41 mm (CC x AP x ML) ≈27 mL, PSA density ~0.42 ng/mL2.
Haemorrhage: none
Peripheral zone (PZ): heterogeneously slightly, decreased signal, linear/wedge-shaped hypointensities
Transition zone (TZ): moderate heterogeneity, focal finding as below:
Focal lesion #1:
- location: left mid gland anterior transition zone from (TZa) extending to the right and from apical to basal
- lesion size: 21 x 13 x16 mm
- T2w: circumscribed homogeneous, hypointense: “erased charcoal sign”, with capsular contact and bulge anteriorly - category 5/5
- DWI: focal slightly hyperintense on DWI (b1000) and markedly hypointense on ADC - category 3/5
- DCE: focal early enhancement - positive
Prostate margin: capsular contact, bulge and breach of the left anterior margin
Overall PI-RADS category: 5
Seminal vesicles: not involved
Lymph nodes: enlarged lymph node adjacent to the left internal iliac vessels (~11 mm), the round suspicious lesion (~6 mm) in the preprostatic fat tissue
Pelvic bones: no osseous metastases
Other pelvic organs: right bladder diverticulum
Impression:
A very highly suspicious lesion in the left anterior transition zone (TZa) and anterior fibromuscular stroma (AFS) with extraprostatic extension.
Highly suspicious lymph nodes in the left iliac fossa and in the preprostatic fat tissue.
MRI putative stage cT3a - PI-RADS 5
A prostate biopsy was recommended.
Case Discussion
This case displays the “erased charcoal sign” in a PI-RADS 5 lesion of the left anterior transition zone (TZa) and anterior fibromuscular stroma (AFS) with extraprostatic extension.
Histology of an MR in-bore biopsy revealed a continuous infiltrate of an acinar adenocarcinoma (modified Gleason score 4+5=9, G2b, high grade) within both cores.
The patient underwent robot-assisted, laparoscopic, bilateral intrafascial, nerve-conserving, radical prostatovesiculectomy with bilateral pelvic lymphadenectomy.
Final histology of the prostatovesiculectomy preparation revealed poorly differentiated acinar adenocarcinoma in both lobes accentuated on the left side with ~40% of prostate volume and with complete capsular penetration and left-sided infiltration of the periprostatic fatty tissue.
Grading G3, Gleason score 5+4=9, WHO grade 5.
Seminal vesicles were free of tumour cells. Interestingly all resected lymph nodes were free of tumour cells.
Tumour classification: pT3a N0 M0 R1.
The patient also received adjuvant intensity-modulated radiotherapy.