A Case Series of Three Soft Tissue Malignant Neoplasms with CRTC1-TRIM11 Fusion in the Head and Neck

Introduction

We present three cases of a rare malignant soft tissue tumor with a CRCT1-TRIM11 fusion gene in the head and neck region. This molecular discovery is associated with a recently identified dermal neoplasm referred to as cutaneous melanocytoma tumor with CRTC1-TRIM 11 translocation (CMTCT), acknowledged as a low-grade malignant tumor originating from surface epithelium. Although these three cases exhibited positivity for the CRTC1-TRIM11 fusion, they showed a mixed immunophenotype and a more aggressive clinical behavior when compared with typical CMTCT cases.

Materials and Methods

Caris Life Sciences, a molecular profiling laboratory conducted RNA sequencing for the three cases. For case one, hematoxylin and eosin stained slides and immunohistochemistry (IHC) stains were performed by the West Virginia University. In contrast, only IHC results were available for cases two and three by Caris Life Sciences.

Results

Clinically, our case series involved two females and one male, aged between 36 and 69 years. Two cases manifested in the nasal cavity, while one occurred in the hard palate. Notably, two cases tested negative for melanocytic markers S-100, HMB-45, and Mart-1/Melan-A, while the third case displayed positivity for all three markers. However, all three cases were positive for CRTC1-TRIM11 translocation. One case also exhibited TERT mutation, while negative for BRAF, NTRK1/2/3, and EWSR1.

Conclusion

The scarcity of robust data on CMTCT and CRTC1-TRIM11 fusion gene poses diagnostic challenges. Our findings offer a comprehensive analysis and explores the intricacies associated with this rare entity to inform improved therapeutic approaches and prognostic predictions. Finally, it raises the question whether the findings represent a lesional spectrum that all share the same molecular perturbation or perhaps an introduction to a new entity.