Histopathologically, a chordoma is characterized by the presence of its hallmark physaliphorous cell, embedded in myxoid to chondromyxoid matrix.
The characteristic physaliphorous cells, showing abundant, pale, eosinophilic, vacuolated cytoplasm and mild nuclear atypia were noted in all cases (Figure 1, A).
Both notochordal vestiges and EPs show the characteristic physaliphorous cells and demonstrate similar immunohistochemical staining pattern.
17) Admixed among the cells are "bubbly" cells containing multiple clear, cytoplasmic vacuoles, indenting the nucleus, which are known as physaliphorous cells.
0), and periodic acid-Schiff stain the cytoplasm of the granular cells and physaliphorous cells, but the clear cytoplasm of the large cells fail to stain.
16) Cytokeratin 18 is reactive in the physaliphorous cells, a supposed, but questionable, distinction from fetal notochordal tissue (see below).
3,4) They all commonly contain univacuolated and physaliphorous cells and have similar immunohistochemical staining patterns, (16) such as positivity for vimentin, S100, epithelial membrane antigen, and low molecular weight cytokeratins and negativity for high molecular weight keratin (34pE12).
In between, an intercellular myxoid matrix is seen, with the classic physaliphorous cells present either individually or forming irregular cords and syncytiae.
Physaliphorous cells were noted (figure 2), which stained strongly for S-100, epithelial membrane antigen (EMA) and, focally, AE1-3 cytokeratin.
Muller in 1958 linked the tumor to notochordal tissue and renamed it "ecchordosis physaliphora" because of the presence of the physaliphorous cells.
Histologically, chordoma is composed of 2 cell populations, multivacuolated physaliphorous cells
(Figure 9, A) and pink epithelioid cells (Figure 9, B), arranged in anastomosing cords in a myxoid or occasionally cartilaginous matrix, the latter typically seen in chondroid chordomas occurring predominantly in the skull base.