PMC3534884_01
Prostate multiparametric MRI and whole mount histopathology correlation. Axial T2-weighted (a) and ADC map of diffusion weighted (b) MR images demonstrate a hypointense lesion (arrow) in right mid anterior central gland suspicious for cancer. MR spectroscopy (c) increases the suspicion for cancer by demonstrating an increased ratio of choline (cho) to citrate (cit) ratio in this right mid anterior central gland lesion (*) when compared with the normal adjacent left side (+). Forward contrast rate [Ktrans] (d) and reverse contrast rate [kep] (e) maps of dynamic contrast enhanced MRI support presence of tumor (arrow). Histopathologic whole mount slide (f) confirms presence of Gleason score 3+3=6 cancer (green dotted line), correlating to the tumor detected on multi-parametric MRI (A = anterior, L = left, P = posterior, R = right). Areas outlined in blue represent BPH.
nihms421793f1.jpg
PMC3534884_01_nihms421793f1.jpg
F1
MRI and apparent diffusion coefficient (ADC) maps of DW MRI. MR spectroscopy revealed a voxel with increased choline/citrate ratio and DCE MRI demonstrated hyper-enhancement within the lesion, supporting the diagnosis of cancer (figure 1a-e). After slicing, histopathologic sections were prepared from the tissue blocks and a Gleason 6 (3+3) lesion was identified in the right anterior central gland (figure 1f).
Customized, patient-specific prostate specimen mold. (a) Three-dimensional representation of final prostate mold in green, shown in two halves with a 3D model of the patient's prostate shown in brown. The mold is labeled with the anatomic boundaries of the prostate (base, apex, left) and two markers for either side of the urethra. Slots placed every 6 mm on the mold correspond anatomically with location of MR axial slices, allowing the prostate to be sectioned such that histologic sections can be registered with MR images. (b) Mold is created using a 3D printer, shown here in two halves fit together using small pegs/slots in the corners.
nihms421793f2.jpg
PMC3534884_01_nihms421793f2.jpg
F2
The mold is generated in two halves as shown (figure 2a) to allow insertion of the prostate specimen. The mold is printed using a 3D printer (Dimension Elite 3D printer, Stratasys, Inc., Eden Prarie, MN, USA) that deposits consecutive 0.010 inch layers of acrylonitrile butadiene styrene (ABS) plastic to create the final prostate mold (figure 2b).
Excised prostate specimen. (a) Specimen shown immediately following excision with seminal vesicles attached, inked as follows to maintain orientation: anterior black, right posterior blue, left posterior red, and urethra yellow. (b) After overnight formalin fixation, seminal vesicles are excised and specimen is placed in the mold with the appropriate orientation, prior to being closed and sectioned.
nihms421793f3.jpg
PMC3534884_01_nihms421793f3.jpg
F3
After surgical excision, the prostate is transported to the pathology lab where the specimen is inked such that the anterior is black, right posterior is blue, left posterior is red, and urethra is yellow (figure 3a). The prostate is oriented in the mold such that the color-coding matches the labels on the mold (figure 3b).
Prostate slicing within the mold and resultant tissue blocks. (a) Mold is closed and clamped to prevent motion or significant tissue deformation while slicing. (b) Resultant 6 mm tissue blocks, arranged from base to apex, are used to create whole mount histopathology slides. These slides can then be correlated 1 to 1 with their corresponding axial MRI slices.
nihms421793f4.jpg
PMC3534884_01_nihms421793f4.jpg
F4
Whole mount sections of the prostate are cut with a single long blade using the mold as a guide creating 6mm tissue blocks (figure 4).