Answer for BIR CoW 20 Nov 2022
Prostatic carcinoma
Findings
Evidence of illdefined T2 hypointense lesion noted replacing bilateral peripheral zones of prostate with loss of pseudo capsule showing significant diffusion restriction with low ADC values Another foci of illdefined T2 hypointensity on the right side of base of prostate with infiltration of anterior neuromuscular stroma ,and shows significant diffusion restriction with low ADC values Extra glandular invasion with loss of normal seminal vesicles Is noted
Discussion
Prostate cancer ranks as the most common primary malignant tumor in men and the second most common cause of cancer-related deaths in men. Prostatic adenocarcinoma is by far the most common histological type It is primarily a disease of the elderly male. In the United States, approximately 200,000 new cases are diagnosed each year. Prostate cancer is usually detected by: an elevated (greater than 4 ng/dL) prostate-specific antigen (PSA); normal is 1-4 ng/dL abnormal digital rectal examination the prostate gland is divided into several anatomic zones and prostate cancer usually arises within the peripheral zone near the rectum, which is why a digital rectal exam (DRE) is a useful screening test 95% of prostate cancers are adenocarcinomas that develop from the acini of the prostatic ducts 15. They arise in the posterior/peripheral (70%) prostate gland more commonly than in the anterior gland and central zone (30%) 21. Prostate cancer can spread by local invasion (typically into the bladder and seminal vesicles; urethral and rectal involvement are rare), lymphatic spread (pelvic nodes first followed by para-aortic and inguinal nodes), or by hematogenous metastases Pathology 95% of prostate cancers are adenocarcinomas that develop from the acini of the prostatic ducts . They arise in the posterior/peripheral (70%) prostate gland more commonly than in the anterior gland and central zone (30%) Prostate cancer can spread by local invasion (typically into the bladder and seminal vesicles; urethral and rectal involvement are rare), lymphatic spread (pelvic nodes first followed by para-aortic and inguinal nodes), or by hematogenous metastases. Common sites of hematogenous metastases are : bone (90%) lung (~45%) liver (~25%) pleura (~20%) adrenal glands (~15%) Microscopic appearance Pathologic specimens are graded using the Gleason score, which is the sum of the most prevalent and second most prevalent types of dysplasia, each on a scale of 1 to 5, with 5 being the most dysplastic. Radiographic features Ultrasound Transrectal ultrasonography (TRUS) is often initially performed to detect abnormalities and to guide biopsy, usually following an abnormal PSA level or DRE. Ultrasound is used to direct the biopsy of suspicious, hypoechoic regions, usually in the peripheral zone. Because of the high incidence of multifocality, systematic sextant biopsies are recommended. On ultrasound, prostate cancer is usually seen as a hypoechoic lesion (60-70%) in the peripheral zone of the gland but can be hyperechoic or isoechoic (30-40% of lesions). Transrectal ultrasound is also the modality of choice for directing brachytherapy seeds into the prostate gland. MRI The primary indication for MRI of the prostate is in the evaluation of prostate cancer after an ultrasound-guided prostate biopsy has confirmed cancer in order to determine if there is extracapsular extension . Increasingly MRI is also being used to detect and localize cancer when the PSA is persistently elevated, but routine TRUS biopsy is negative. Both the American College of Radiology (ACR) and the European Society of Uroradiology (ESUR) advocate the use of multiparametric MRI (mpMRI) in prostate imaging . MRI-guided prostate biopsy is also being used, particularly in those cases where TRUS biopsy is negative but clinical and PSA suspicion remains high . Following radical prostatectomy, patients with elevated PSA should also be examined using MRI. Often a PI-RADS score is given to assess the probability of the lesion being malignant. Signal characteristics T1: useful for detection of prostate contour, neurovascular bundle encasement, and post-biopsy hemorrhage T2 using an endorectal coil, on T2-weighted images prostate cancer usually appears as a region of low signal within a normally high signal peripheral zone most significant cancers occur along the posterior portion of the prostate gland abutting the rectum DWI/ADC: often shows restricted diffusion dynamic contrast enhancement (DCE): (dynamic contrast enhancement in prostate cancer) shows enhancement but it can be difficult to distinguish from prostatitis or benign prostatic hyperplasia (especially in the central zone lesions ) more specific than T2 signal involves post-processing time MR spectroscopy: (MR-spectroscopy in prostate cancer) increased choline: citrate or choline+creatine: citrate ratios are seen in prostate cancer (see below for more details) Routine use of body 3.0 T magnets now means that endorectal coils have become unnecessary for prostate imaging due to the improved signal to noise and spatial resolution associated with higher field strength. MRI parameters routinely assessed include the presence of a mass with a low T2 signal, restricted diffusion with reduced ADC, and increased tissue capillary permeability using dynamic contrast-enhanced (DCE) imaging and calculation of the so-called Ktrans (a calculated time constant for permeability). These so-called multiparametric techniques are increasingly being used in the assessment of prostate malignancy with MRI . Extracapsular extension carries a poor prognosis. Assess for: asymmetry/extension into the neurovascular bundles obliteration of the rectoprostatic angle involvement of the urethra seminal vesicle invasion (normal seminal vesicles have a high signal on T2) Lymphadenopathy is best appreciated on T1-weighted images.
References
1. Hricak H, Choyke P, Eberhardt S, Leibel S, Scardino P. Imaging Prostate Cancer: A Multidisciplinary Perspective. Radiology. 2007;243(1):28-53. doi:10.1148/radiol.2431030580 - Pubmed
2. Thornbury J, Ornstein D, Choyke P, Langlotz C, Weinreb J. Prostate Cancer: What is the Future Role for Imaging? AJR Am J Roentgenol. 2001;176(1):17-22. doi:10.2214/ajr.176.1.1760017 - Pubmed
Findings
Evidence of illdefined T2 hypointense lesion noted replacing bilateral peripheral zones of prostate with loss of pseudo capsule showing significant diffusion restriction with low ADC values Another foci of illdefined T2 hypointensity on the right side of base of prostate with infiltration of anterior neuromuscular stroma ,and shows significant diffusion restriction with low ADC values Extra glandular invasion with loss of normal seminal vesicles Is noted
Discussion
Prostate cancer ranks as the most common primary malignant tumor in men and the second most common cause of cancer-related deaths in men. Prostatic adenocarcinoma is by far the most common histological type It is primarily a disease of the elderly male. In the United States, approximately 200,000 new cases are diagnosed each year. Prostate cancer is usually detected by: an elevated (greater than 4 ng/dL) prostate-specific antigen (PSA); normal is 1-4 ng/dL abnormal digital rectal examination the prostate gland is divided into several anatomic zones and prostate cancer usually arises within the peripheral zone near the rectum, which is why a digital rectal exam (DRE) is a useful screening test 95% of prostate cancers are adenocarcinomas that develop from the acini of the prostatic ducts 15. They arise in the posterior/peripheral (70%) prostate gland more commonly than in the anterior gland and central zone (30%) 21. Prostate cancer can spread by local invasion (typically into the bladder and seminal vesicles; urethral and rectal involvement are rare), lymphatic spread (pelvic nodes first followed by para-aortic and inguinal nodes), or by hematogenous metastases Pathology 95% of prostate cancers are adenocarcinomas that develop from the acini of the prostatic ducts . They arise in the posterior/peripheral (70%) prostate gland more commonly than in the anterior gland and central zone (30%) Prostate cancer can spread by local invasion (typically into the bladder and seminal vesicles; urethral and rectal involvement are rare), lymphatic spread (pelvic nodes first followed by para-aortic and inguinal nodes), or by hematogenous metastases. Common sites of hematogenous metastases are : bone (90%) lung (~45%) liver (~25%) pleura (~20%) adrenal glands (~15%) Microscopic appearance Pathologic specimens are graded using the Gleason score, which is the sum of the most prevalent and second most prevalent types of dysplasia, each on a scale of 1 to 5, with 5 being the most dysplastic. Radiographic features Ultrasound Transrectal ultrasonography (TRUS) is often initially performed to detect abnormalities and to guide biopsy, usually following an abnormal PSA level or DRE. Ultrasound is used to direct the biopsy of suspicious, hypoechoic regions, usually in the peripheral zone. Because of the high incidence of multifocality, systematic sextant biopsies are recommended. On ultrasound, prostate cancer is usually seen as a hypoechoic lesion (60-70%) in the peripheral zone of the gland but can be hyperechoic or isoechoic (30-40% of lesions). Transrectal ultrasound is also the modality of choice for directing brachytherapy seeds into the prostate gland. MRI The primary indication for MRI of the prostate is in the evaluation of prostate cancer after an ultrasound-guided prostate biopsy has confirmed cancer in order to determine if there is extracapsular extension . Increasingly MRI is also being used to detect and localize cancer when the PSA is persistently elevated, but routine TRUS biopsy is negative. Both the American College of Radiology (ACR) and the European Society of Uroradiology (ESUR) advocate the use of multiparametric MRI (mpMRI) in prostate imaging . MRI-guided prostate biopsy is also being used, particularly in those cases where TRUS biopsy is negative but clinical and PSA suspicion remains high . Following radical prostatectomy, patients with elevated PSA should also be examined using MRI. Often a PI-RADS score is given to assess the probability of the lesion being malignant. Signal characteristics T1: useful for detection of prostate contour, neurovascular bundle encasement, and post-biopsy hemorrhage T2 using an endorectal coil, on T2-weighted images prostate cancer usually appears as a region of low signal within a normally high signal peripheral zone most significant cancers occur along the posterior portion of the prostate gland abutting the rectum DWI/ADC: often shows restricted diffusion dynamic contrast enhancement (DCE): (dynamic contrast enhancement in prostate cancer) shows enhancement but it can be difficult to distinguish from prostatitis or benign prostatic hyperplasia (especially in the central zone lesions ) more specific than T2 signal involves post-processing time MR spectroscopy: (MR-spectroscopy in prostate cancer) increased choline: citrate or choline+creatine: citrate ratios are seen in prostate cancer (see below for more details) Routine use of body 3.0 T magnets now means that endorectal coils have become unnecessary for prostate imaging due to the improved signal to noise and spatial resolution associated with higher field strength. MRI parameters routinely assessed include the presence of a mass with a low T2 signal, restricted diffusion with reduced ADC, and increased tissue capillary permeability using dynamic contrast-enhanced (DCE) imaging and calculation of the so-called Ktrans (a calculated time constant for permeability). These so-called multiparametric techniques are increasingly being used in the assessment of prostate malignancy with MRI . Extracapsular extension carries a poor prognosis. Assess for: asymmetry/extension into the neurovascular bundles obliteration of the rectoprostatic angle involvement of the urethra seminal vesicle invasion (normal seminal vesicles have a high signal on T2) Lymphadenopathy is best appreciated on T1-weighted images.
References
1. Hricak H, Choyke P, Eberhardt S, Leibel S, Scardino P. Imaging Prostate Cancer: A Multidisciplinary Perspective. Radiology. 2007;243(1):28-53. doi:10.1148/radiol.2431030580 - Pubmed
2. Thornbury J, Ornstein D, Choyke P, Langlotz C, Weinreb J. Prostate Cancer: What is the Future Role for Imaging? AJR Am J Roentgenol. 2001;176(1):17-22. doi:10.2214/ajr.176.1.1760017 - Pubmed
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!