title: Extraskeletal myxoid chondrosarcoma with neuroendocrine differentiation: a case report with fine-needle aspiration biopsy, histopathology, electron microscopy, and cytogenetics.
abstract: Although extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue sarcoma, its morphological, ultrastructural, and cytogenetical features have been well investigated. The authors describe a very rare variant of EMC with neuroendocrine differentiation. A 49-year-old woman presented with an 11-cm, deep-seated, lobulated soft tissue mass in the left thigh and a lymph node metastasis in the left groin. Analysis of fine-needle aspiration biopsy (FNAB) smears and a cellblock prepared from FNAB material, as well as histological sections of the excised tumor, showed a neoplasm composed of rounded and elongated cells arranged in strands and cords in a myxoid background matrix. The nuclei were rounded and often eccentric. The immunohistochemical phenotype was S-100 protein -, neuron specific enolase +, and chromogranin A+. Electron microscopy showed tumor cells harboring numerous mitochondria, partial basal lamina, and unequivocal neuroendocrine granules. Molecular genetic analysis revealed a TAF15/NR4A3 fusion, a characteristic rearrangement occurring in about 25% of cytogenetically investigated EMC. A few cases of EMC with neuroendocrine differentiation have been reported. However, the only previously described case with genetic information also displayed the t(9;17) instead of the more common t(9;22), suggesting an association between type of primary chromosome abnormality and neuroendocrine differentiation.
authors.affiliation: Department of Pathology and Cytology, Lund University Hospital, Lund, Sweden. henryk.domanski@pat.lu.se
authors.forename: Henryk A
authors.initials: HA
authors.lastname: Domanski
authors.forename: Birgitta
authors.initials: B
authors.lastname: Carlén
authors.forename: Fredrik
authors.initials: F
authors.lastname: Mertens
authors.forename: Måns
authors.initials: M
authors.lastname: Akerman
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002813:Chondrosarcoma / Q000737:chemistry / Q000235:genetics / Q000556:secondary*; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis; D002886:Chromosomes, Human, Pair 17; D002899:Chromosomes, Human, Pair 9; D020732:Cytogenetic Analysis; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009490:Neurosecretory Systems / Q000737:chemistry / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D010751:Phosphopyruvate Hydratase / Q000032:analysis; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor; D053379:Chromogranin A; D002864:Chromogranins; D004273:DNA, Neoplasm; D015514:Oncogene Proteins, Fusion; D010751:Phosphopyruvate Hydratase