title: NR4A3 rearrangement reliably distinguishes between the clinicopathologically overlapping entities myoepithelial carcinoma of soft tissue and cellular extraskeletal myxoid chondrosarcoma.
abstract: Myoepithelial carcinoma of soft tissue (MEC) and cellular extraskeletal myxoid chondrosarcoma (cEMC) share striking similarities. In this paper, we compare ten MECs with five cEMCs. MEC patients had an equal gender distribution. The age range was 15-76 years (mean, 42 years). Tumours were located on extremities, pelvic girdle, vulva and neck. Follow-up, available for nine patients, ranged from 4 to 85 months (mean, 35 months). Five patients were alive without evidence of disease, two were alive with disease and two died 8 months after the initial diagnosis. cEMCs were from three males and two females with an age range of 37-82 years (mean, 57 years); they presented in extremities, shoulder and paravertebral/cervical. Follow-up, available for four patients, ranged from 6 to 220 months (mean, 61 months). All patients were alive, two with recurrences and/or metastases and two without evidence of disease. Morphologically, the distinction between these two entities was difficult since all cases exhibited features typically seen in myoepithelial tumours. Immunohistochemically, MECs expressed pan-keratin (80 %), epithelial membrane antigen (EMA; 57 %), S100 (50 %), alpha-smooth muscle actin (ASMA; 75 %), calponin (67 %) and p63 (25 %). S100 and EMA were expressed in 40 % of cEMC cases respectively with additional immunoreactivity for p63, ASMA and glial fibrillary acidic protein in one case. Pan-keratin was negative in all neoplasms. NR4A3 rearrangement was present in four of four cEMCs and in none of the MECs. In contrast, three of nine (33 %) MECs and four of five (80 %) cEMCs showed an EWSR1 rearrangement. In summary, MECs and cEMCs share clinical, morphological, immunohistochemical and genetic characteristics. The pathognomic rearrangement of NR4A3 is a useful diagnostic feature in identifying cEMCs.
authors.affiliation: Department of Pathology, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 Nijmegen, The Netherlands. u.flucke@pathol.umcn.nl
authors.forename: Uta
authors.initials: U
authors.lastname: Flucke
authors.forename: Bastiaan B J
authors.initials: BB
authors.lastname: Tops
authors.forename: Marian A J
authors.initials: MA
authors.lastname: Verdijk
authors.forename: Patricia J H
authors.initials: PJ
authors.lastname: van Cleef
authors.forename: Peter H
authors.initials: PH
authors.lastname: van Zwam
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Slootweg
authors.forename: Judith V M G
authors.initials: JV
authors.lastname: Bovée
authors.forename: Robert G
authors.initials: RG
authors.lastname: Riedl
authors.forename: David H
authors.initials: DH
authors.lastname: Creytens
authors.forename: Albert J H
authors.initials: AJ
authors.lastname: Suurmeijer
authors.forename: Thomas
authors.initials: T
authors.lastname: Mentzel
mesh_terms: D000328:Adult; D000368:Aged; D002148:Calmodulin-Binding Proteins / Q000235:genetics; D002813:Chondrosarcoma / Q000235:genetics / Q000473:pathology*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007633:Keratins / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D009208:Myoepithelioma / Q000235:genetics / Q000473:pathology*; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins / Q000235:genetics; D011987:Receptors, Steroid / Q000235:genetics*; D011988:Receptors, Thyroid Hormone / Q000235:genetics*; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000473:pathology*
chemical_list: D002148:Calmodulin-Binding Proteins; D004268:DNA-Binding Proteins; C500986:EWSR1 protein, human; C490412:NR4A3 protein, human; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins; D011987:Receptors, Steroid; D011988:Receptors, Thyroid Hormone; D007633:Keratins