Recutting Blocks of Prostate Needle Biopsies: How Much Diagnostic Yield Is Gained?

Efficient 3D light-sheet imaging of very large-scale optically cleared human brain and prostate tissue samples

The ability to image human tissue samples in 3D, with both cellular resolution and a large field of view (FOV), can improve fundamental and clinical investigations. Here, we demonstrate the feasibility of light-sheet imaging of ~5 cm³ sized formalin fixed human brain and up to ~7 cm³ sized formalin fixed paraffin embedded (FFPE) prostate cancer samples, processed with the FFPE-MASH protocol. We present a light-sheet microscopy prototype, the cleared-tissue dual view Selective Plane Illumination Microscope (ct-dSPIM), capable of fast 3D high-resolution acquisitions of cm³ scale cleared tissue. We used mosaic scans for fast 3D overviews of entire tissue samples or higher resolution overviews of large ROIs with various speeds: (a) Mosaic 16 (16.4 µm isotropic resolution, ~1.7 h/cm³), (b) Mosaic 4 (4.1 µm isotropic resolution, ~ 5 h/cm³) and (c) Mosaic 0.5 (0.5 µm near isotropic resolution, ~15.8 h/cm³). We could visualise cortical layers and neurons around the border of human brain areas V1&V2, and could demonstrate suitable imaging quality for Gleason score grading in thick prostate cancer samples. We show that ct-dSPIM imaging is an excellent technique to quantitatively assess entire MASH prepared large-scale human tissue samples in 3D, with considerable future clinical potential.

Diagnostic Utility and Significance of Performing Multistep Level Sections in Breast and Gynecologic Biopsy Specimens

OBJECTIVES

The significance of performing multistep level sections, including preparation of unstained sections in breast and gynecologic biopsy specimens, has been studied.

METHODS

Consecutive H&E-stained level sections of 785 atypical and malignant biopsy specimens were included. The diagnostic material was categorized into present, absent, increased in size, or depleted. If the multistep level sections helped in establishing the diagnosis after a nondiagnostic material or the tissue significantly increased in size, this was considered a positive impact.

RESULTS

No effect and positive impact of performing multistep level sections were obtained in 84.8% and 15.2% by preparing a second level and 97.2% and 2.8% by preparing a third level, respectively. Eighteen (2.3%) of the diagnoses could have been missed without performing a second level, while 8 (1%) could have been missed without performing a third level. The intervening unstained sections were used in 27 of 785 (3.4%) of the cases.

CONCLUSIONS

Staining two level sections with H&E significantly affected the diagnosis. However, preparing a third level did not improve the diagnosis. A universal protocol should be considered to standardize the handling of biopsy specimens among laboratories.