extraskeletal myxoid chondrosarcoma
Definition: Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant tumour, that represents less of 3 per cent of the soft tissue sarcomas, and is part of the tumours of uncertain differentiation, according to the WHO classification.
Overall survival is good but frequent local tumour recurrences are observed.
Synopsis
short cords of small monomorphic cells, often rounded
myxoid substance
Immunochemistry
vimentin+
NSE+
CD56+
Variable expression of S100 protein, epithelial markers and synaptophysin.
Cytogenetics
t(9;22)(q22;q12)
- Balanced translocation t(9;22)(q22;q12) is found in 70 per cent of the cases.
Differential diagnosis
Some problems of differential diagnosis can occur, especially with chordomas and tumors with myxoid stroma.
References
Meis-Kindblom JM, Bergh P, Gunterberg B, Kindblom LG : Extraskeletal myxoid chondrosarcoma : a reappraisal of its morphologic spectrum and pronostic factors based on 117 cases. Am J Surg Pathol 1999;23:636-50.
Oliveira AM, Sebo TJ, McGrory JE, Gaffey TA, Rock MG, Nascimento AG : Extraskeletal myxoid chondrosarcoma : A clinicopathologic, immunohistochemical, and ploidy analysis of 23 cases. Mod Pathol 2000;13(8):900-8.
Goh YW, Spagnolo DV, Platten M, Caterina P, Fisher C, Oliveira AM, et al.: Extraskeletal myxoid chondrosarcoma : a light microscopic, immunohistochemical, ultrastructural and immunoultrastructural study indicating neuroendocrine differentiation. Histopathology 2001;39(5):514-24.