Incidental findings in and around the prostate on prostate MRI

[madman]

Table 4 Spermatic cord neoplasms [30–33]

 

[madman]

Fig. 17 UPS of the spermatic cord a Coronal T1 fat sat post-contrast and b axial T2 fat sat images show a large heterogeneously enhancing high T1 and T2 signal mass within the left inguinal canal and scrotum (red arrow). c Axial DWI and d ADC images demonstrate a predominantly solid mass with restricted diffusion in keeping with necrosis or cystic change within

 

[madman]

Fig. 18 Spermatic cord lymphoma a Axial T1W image shows a mass within the right inguinal canal (white arrow) which is inseparable from the spermatic cord and is mildly hyperintense to gluteus muscle and shows heterogeneous post-contrast enhancement on (b) T1 fat saturation and (c) T2 fat saturation sequences. In d and e axial DWI/ ADC, the right inguinal mass shows restricted diffusion. This was surgically excised and proven to be spermatic cord lymphoma

 

[madman]

Fig. 19 Urothelial carcinoma a Axial T1W image shows a slightly T1 hypointense lesion (white arrow) compared to the gluteus maximus muscle in the left vesicoureteric junction. b Axial T2W image in the same patient shows the left VUJ filling defect which is T2 hyperintense to the bladder wall and gluteal muscle. c Is an axial T2W image of a different patient showing an intermediate signal intensity polypoid lesion on the left posterior bladder wall (white arrow). d Is an axial T2W image of yet another patient with a history of urothelial carcinoma showing multiple ill-defined, T2 hyperintense to gluteus muscle, nodules in the perineum and extending to the ventral aspect of the penis in keeping with metastases (white arrow)

 

[madman]

Table 5 Differentials for inguinal canal mass that may be seen on prostate MRI [37, 38]

 

[madman]

Fig. 20 Axial T2W images demonstrate a moderately high T2 signal mass in the right inguinal region (white arrow) which was contiguous with small bowel on serial images and in keeping with a right-sided small bowel containing inguinal hernia. The prostate is labeled by the black arrow

 

[madman]

Fig. 21 Ascites a Sagittal and b coronal T2-weighted images demonstrate high T2 signal-free fluid (white arrows) of similar intensity to the urinary bladder in keeping with ascites. The fluid is seen posterior and superior to the prostate (blue arrow) at the base of the bladder. a Also shows a 4 mm nodule (red arrow) in the anterior inferior aspect of the free fluid

 

[madman]

Fig. 22 GIST well-circumscribed submucosal 5 cm heterogeneous mass (white arrow) arising from the right posterolateral wall of the lower rectum is (a) predominantly T2 hyperintense relative to the rectal wall with (b) and (c) sagittal and axial T1 fat saturation post-contrast sequences showing vivid contrast enhancement. The mass is seen posterior to the prostate in B (red arrow). A biopsy confirmed spindle-type histologically low-grade GIST

 

[madman]

Fig. 23 Rectal villous adenoma a Axial and (b) sagittal T2W images show a large lobulated polypoid mass within the lower rectum at 2 cm from the anal verge (white arrow). The mass shows a thick T2 hyperintense layer along the surface with heterogeneous intermediate to high-signal intensity within the lesion. c Colonoscopy and polypectomy confirmed villous/ tubulovillous adenoma (black arrow) with low-grade dysplasia

 

[madman]

Fig. 24 Rectal adenocarcinoma Axial, sagittal, and coronal T2-weighted images showing a semi-annular mass (red arrow), posterior to the prostate and within the rectum which is T2 hyperintense to gluteal muscle and extending from 3 to 1 o’clock causing significant luminal narrowing. Colonoscopy and biopsy proved rectal adenocarcinoma

 

[madman]

Fig. 25 Periprostatic venous varix a Axial T2W image shows a flow void (white arrow) to the right of the prostate gland (red arrow) and (b) dynamic post-contrast axial T1W image shows dynamic enhancement confirming a right-sided periprostatic venous varix

 

[madman]

Fig. 26 Lymphadenopathy in a patient with multiple myeloma a Axial DWI and (b) ADC images showing diffusion restriction in a rounded lesion to the left of the urinary bladder anteriorly (white arrows) in keeping with nodal metastasis in left external iliac lymph nodes. Diffusion restriction also in the acetabulum bilaterally (red arrows) in keeping with marrow infiltration. c Axial T2W images demonstrate the left external iliac lymph node is iso- to hyperintense relative to surrounding fat which is seen in nodal metastasis

 

[madman]

Key points

• Familiarity with MRI signal characteristics of blood, calcifications and cyst fluid are important.

• Location of the incidental finding narrows the differential list as some pathologies occur more frequently in certain sites.

• Prostate abscess can have similar imaging characteristics to prostate cancer; history and clinical presentation are useful to distinguish.

• Recent prostate or peri-prostate interventions can mimic pathology.

 

[Blackhawk]

I had 3T MP MRI due to high PSA and LUTS. I can add another incidental discovery: Leukemia in the bone marrow. Had i not already known I had the Leukemia, the MRI (and the biopsy) would have led to diagnosis. The bone marrow in the MRI was lit up brightly and the biopsy result was Infiltration of the prostate by Lymphocytic Leukemia, not prostate cancer.