Retroperitoneal pararenal dedifferentiated liposarcoma with epithelioid/neuroendocrine features, somatostatin-positive.

Liposarcomas are malignant mesenchymal neoplasms that, although derived from adipocytes, may dedifferentiate to other cell types. We present an exceedingly rare case of epithelioid/neuroendocrine dedifferentiation with somatostatin expression of a pararenal retroperitoneal liposarcoma.

Based on the immunomorphological features, the diagnosis was possible with the support of the molecular FISH investigation: it showed amplification of the MDM2 gene, which is present in most liposarcomas, even in dedifferentiated ones.