{Reference Type}: Case Reports
{Title}: Fusion of the Genes for Interferon Regulatory Factor 2 Binding Protein 2 (IRF2BP2) and Caudal Type Homeobox 1 (CDX1) in a Chondrogenic Tumor.
{Author}: Panagopoulos I;Gorunova L;Lobmaier I;Heim S;
{Journal}: In Vivo
{Volume}: 37
{Issue}: 6
{Year}: 2023 Nov-Dec
{Factor}: 2.406
{DOI}: 10.21873/invivo.13352
{Abstract}: <B>OBJECTIVE: </B>Chondrogenic tumors are benign, intermediate or malignant neoplasms showing cartilaginous differentiation. In 2012, we reported a mesenchymal chondrosarcoma carrying a t(1;5)(q42;q32) leading to an IRF2BP2::CDX1 fusion gene. Here, we report a second chondrogenic tumor carrying an IRF2BP2::CDX1 chimera.<BR><B>METHODS: </B>Radiological examination of a 41 years old woman showed an osteolytic lesion in the os pubis with a large soft tissue component. Examination of a core needle biopsy led to the diagnosis chondromyxoid fibroma, and the patient was treated with curettage. Microscopic examination of the specimen showed a tumor tissue in which a pink-bluish background matrix was studded with small spindled to stellate cells without atypia, fitting well the chondromyxoid fibroma diagnosis. Focally, a more cartilage-like appearance was observed with cells lying in lacunae and areas with calcification. G-banding analysis of short-term cultured tumor cells yielded the karyotype 46,XX,der(1)inv(1)(p33~34q42) add(1)(p32)?ins(1;?)(q42;?),del(5)(q31),der(5)t(1;5)(q42;q35)[12]/46,XX[3]. RT-PCR together with Sanger sequencing showed the presence of two IRF2BP2::CDX1 chimeric transcripts in which exon 1 of the IRF2BP2 reference sequence NM_182972.3 or NM_001077397.1 was fused to exon 2 of CDX1. Both chimeras were predicted to code for proteins containing the zinc finger domain of IRF2BP2 and homeobox domain of CDX1.<BR><B>CONCLUSIONS: </B>IRF2BP2::CDX1 chimera is recurrent in chondrogenic tumors. The data are still too sparse to conclude whether it is a hallmark of benign or malignant tumors.