Crush preparation findings of "sarcomatoid" chordoma of the sacrum: Reportof a case with histologic, immunohistochemical, and ultrastructural correlation

We report on the crush preparation findings of a case of "sarcomatoid" chor doma occurring in the sacral region of a 78-yr-old Chinese male, The smears showed clumps and small cords of polygonal tumor cells containing bubbly c ytoplasm and round to oval nuclei. Focally, there ii,cre also aggregates of long filamentous spindle cells and stellate bizarre cells with marked nucl ear pleomorphism. Occasional tumor cells ii,ere seen in association with de nse amorphous Material, Histologic examination of the excised specimen show ed features of the so-called "sarcomatoid" chordoma which consisted of prom inent foci of mitotically inactive spindle and pleomorphic cells, in additi on to the conventional chordoma areas. An osteosarcoma-like pattern Of prob ably metaplastic nature ii,as also seen within the tumor. Immunohistochemic al study showed that most tumor cells expressed cytokeratins. Ultrastructur al examination revealed the characteristic rough endoplasmic reticulum-mito chondria complexes. While there are many spindle and pleomorphic cells seen in crush preparations, the distinction from other true high-grade malignan cies is important. Recognition of these "pseudoanaplastic" cytologic featur es also helps to expand the morphologic spectrum of chordoma. (C) 2001 Wile y-Liss, Inc.