J Pathol Transl Med.  2023 May;57(3):184-187. 10.4132/jptm.2023.03.20.

What’s new in bone and soft tissue pathology 2023: guidelines for molecular testing

• Obeidin F

• KMID: 2542285
• DOI: http://doi.org/10.4132/jptm.2023.03.20

Abstract

Our understanding of bone and soft tissue tumors has thoroughly evolved as a consequence of modern molecular techniques. DNA and RNA sequencing methods play an important diagnostic and therapeutic role in sarcoma pathology. Herein, we discuss current guidelines and best practices for molecular testing in bone and soft tissue tumors.

Figure

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  Fig. 1. A t-distributed stochastic neighbor embedding (t-SNE) plot is a visualization method used in clinical laboratories to show the aggregate methylation data of a tumor. Each dot represents a single tumor and the closeness of the dots represents similarity in their methylation profiles. From this, a classification scheme can be created. Each cluster represents a separate tumor type. In this example case, the black dot is the current tumor and is clustering near the category of MYOD1-mutated rhabdomyosarcoma.

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  Fig. 2. MDM2 amplification, seen here as an increase in red fluorescent probe signals, is a hallmark of certain cancers. The prototypical example is well-differentiated/dedifferentiated liposarcoma.

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  Fig. 3. New NGS methods are highly sensitive and specific for translocations and can also be used to detect new fusions with previously undescribed partners. This example shows the readout from the NGS software demonstrating a fusion of the USP6 gene with the SERPINF1 gene in a case of nodular fasciitis.