20.500.12556/RUL-148046 Subcutaneous chondromyxoid fibroma with a novel PNISR::GRM1 fusion—report of a primary soft tissue tumour without connection to an underlying bone Chondromyxoid fibroma (CMF) is a rare benign bone tumour. While CMF located entirely on the surface of a bone (i.e. juxtacortical CMF) has been well characterised, CMF has not so far been convincingly documented to arise in soft tissues without connection to an underlying bone. We report a subcutaneous CMF in a 34-year-old male, located on the distal medial aspect of the right thigh without any connection with the femur. The tumour measured 15 mm, it was well-circumscribed and displayed typical morphological features of a CMF. At the periphery, there was a small area of metaplastic bone. Immunohistochemically, the tumour cells were diffusely positive for smooth muscle actin and GRM1, and negative for S100 protein, desmin and cytokeratin AE1AE3. Whole transcriptome sequencing revealed a novel PNISR::GRM1 gene fusion. Our case indicates that CMF should be included in the differential diagnosis of soft tissue (including subcutaneous) tumours composed of spindle/ovoid cells, with a lobular architecture and chondromyxoid matrix. The diagnosis of CMF arising in soft tissues can be confirmed by identifying a GRM1 gene fusion or GRM1 expression by immunohistochemistry. chondromyxoid fibroma extraosseous tumour GRM1 MEF2A::ARHGAP36 PNISR::GRM1 subcutaneous tumour hondromiksoidni fibrom zunajkostni tumor GRM1 true false true Angleški jezik Slovenski jezik Članek v reviji 2023-07-26 12:48:30 2023-07-26 12:48:44 2024-09-30 09:56:34 0000-00-00 00:00:00 2023 0 0 Str. 917-921 iss. 5 Vol. 482 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616 0945-6317 10.1007/s00428-023-03519-4 142570499 s00428-023-03519-4.pdf s00428-023-03519-4.pdf 1 4D1F7E3FC30C162107856B521ECA16F0 420ac19c90859b3fcef4d31b4601c1b8707861b1db03036e6171def6868a6e49 5cd1ec1d-2ba2-11ee-aeaf-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=171984 https://link.springer.com/article/10.1007/s00428-023-03519-4 1 187160da-2ba2-11ee-aeaf-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=171983 Medicinska fakulteta 0 0 0