Akademik Veri Yönetim Sistemi
35th European Congress of Pathology, Dublin, İrlanda, 9 - 13 Eylül 2023, ss.184-185
Background & objectives
CRTC1::TRIMM11 cutaneous tumor is a new entity in the 5th edition of WHO classification. It
commonly occurs in the extremities of patients of various ages. Although they are expected to
behave indolently, the scarcity of cases makes this uncertain.
Methods
We present the case of a 14-year-old girl with a 1 cm exophytic nodular lesion on the shoulder
that was clinically suspected to be a sweat gland tumor. The lesion was excised for
pathological examination. In addition to light microscopy, immunohistochemical analysis (IHC-
a), fluorescence in situ hybridization (FISH) and Next-generation sequencing (NGS) were
performed.
Results
Histopathological analysis revealed a spindle-cell tumor in the dermis with a well-
circumscribed border. The tumor cells had large cytoplasm without pigment, and some of them
had conspicuous nucleoli. They were arranged in intersecting fascicles, with striking fibrous
bundles weaving in between them. The mitotic rate was very low and atypical forms were not
observed. The differential diagnoses included melanocytic tumors and dermal clear cell
sarcoma. IHC-a demonstrated focal S100 and diffuse SOX10 positivity. Melan-A, HMB45,
PRAME, PANTRK, and BRAF-VE1 were negative. EWSR rearrangement was investigated
using a break-apart FISH probe and the results were negative. RNA sequencing using NGS
revealed a CRTC1::TRIMM11 translocation.
Conclusion
Dermal tumors with a differential diagnosis of clear cell sarcoma or metastatic melanoma with
SOX10 expression and negative EWSR rearrangement, should raise suspicion for
CRTC1::TRIMM11 cutaneous tumor. We believe that with increased awareness of this entity,
more cases will be identified, leading to the accumulation of demographic, histopathological,
and clinical data.