Improving Cassette to Slide Traceability in Large Format Histology

Large tissue specimens create a different identification challenge from routine histology samples. A standard cassette usually contains a relatively small tissue fragment, while large format histology is used when laboratories want to preserve a broader view of the original anatomy in a single section. The purpose is not simply to place more tissue on one slide. In some cases, dividing a specimen into many smaller blocks can make important spatial relationships harder to see.

Taking prostate cancer as an example. Prostate cancer can be multifocal, meaning several separate tumor foci may exist within the same gland. During radical prostatectomy evaluation, the pathologist may need to understand not only whether cancer is present, but also where the main tumor is located, how far it extends, whether other tumor foci are present, how close the tumor is to the surgical margin, and whether there is extension beyond the prostate.

Whole mount prostate section under digital review.

In the normal pathology workflow, when a complete prostate cross section is divided into several conventional blocks, each section can still be examined individually. However, the pathologist then has to mentally reconstruct how those smaller pieces originally related to one another, which may lead to potential mistakes. The tumor may continue across more than one block, and the relationship between the tumor, capsule, surrounding tissue, and surgical margin can become less direct.

Whole mount or large format histology helps preserve that relationship. A much larger prostate cross section can remain together in one cassette and later be placed on one mega slide. This allows the pathologist to see a broader portion of the gland in its original anatomical arrangement and makes tumor location and extent easier to understand.

Large prostate section divided into multiple smaller tissue regions.

This can also be useful when pathology findings are compared with imaging. MRI presents the prostate as a complete anatomical structure and may identify a suspicious lesion in a particular location. If the corresponding histology is divided into many separate pieces, matching the imaging finding with the final pathology can become more complicated. A large format section preserves more of the original anatomical plane and can make that comparison more straightforward.

Preserving more anatomy also creates a greater need for reliable specimen identification. The large cassette used during processing and the final mega slide produced after embedding and sectioning represent the same specimen at different stages. Information such as the case number, specimen identifier, orientation, and barcode needs to remain consistent as the tissue moves through the workflow. If cassette information and slide information are recreated separately, every additional manual entry or transfer creates another opportunity for mismatch.

This is the type of workflow the TBG100 was designed to support.

TBG100 designed for large tissue specimens

The TBG100 can print both large tissue cassettes and mega slides used in large format histology. Cassette printing and slide printing still happen at different stages of the laboratory process, but the important point is that both can remain connected to the same specimen information.

Large format specimens may also require more information to remain visible on the printed surface. Case numbers, specimen identifiers, orientation references, barcodes, and other details may all be important when handling a large prostate section. The larger labeling area gives laboratories more space to organize this information clearly.

The TBG100 uses UV laser marking for both cassettes and slides, creating the identification directly on the printable surface without relying on ribbon consumables. For a specimen that passes through multiple processing and handling stages, the goal is not simply to create a readable label when printing begins. The information also needs to remain clear when the tissue reaches later stages of the workflow.

The main value of the TBG100 is therefore not simply that it can print two different formats. Its purpose is to help laboratories maintain the information connection behind a large format specimen. In prostate whole mount histology, a larger section helps preserve the relationship between tumor foci, surrounding anatomy, and surgical margins. The labeling workflow should preserve the identity and orientation behind that section just as carefully.