Calcifying epithelial odontogenic tumor of pindborg.An electron microscopic study

Abstract

A calcifying epithelial odontogenic tumor of Pindborg was examined with the electron microscope. The tumor cells demonstrated fine structural features commonly seen in epidermal cells, i.e., intercellular bridges with desmosomes, intracytoplasmic tonofilaments, and well‐developed hemidesmosomes. A thin linear condensation was observed within die lamina lucida of hemidesmosomes which probably represents a normal component of these attachments. A copious extracellular matrix was seen which was composed largely of fine fibrils, approximately 50 Å in width, aggregated to form a structure resembling a basal lamina. The possibility that this fibrillar extracellular matrix represents amyloid was discussed. Calcospherites were present within the matrix, occasionally in association with fragmented tumor cell cytoplasm. They appeared to lack collagen and were composed primarily of electron dense needles resembling hydroxyapatite.

A clinical and electron microscopic study of a calcifying epithelial odontogenic tumour

“…The ultrastructural features of the tumour cells were recently described by Anderson, Kim, and Minkowitz (1969) and we can confirm their findings. The cells show features commonly seen in epidermal cells in keeping with origin from the enamel organ or oral epithelium.…”

“…Anderson et al (1969) argued that they might represent basal lamina. Despite giving the histochemical reactions of amyloid, the fibre size is smaller than that of classical amyloid (Sorenson and Shimamura, 1964).…”

The duality of the cell population in a calcifying epithelial odontogenic tumour (CEOT)

“…This fine structure, together with the positive reaction to both Congo red and thioflavine T, suggests that these filaments are probably a sort of amyloid as has previously been shown by Ranlov & Pindborg ( The tumour cells I The epithelial cells: Both light and ultrastructural morphology of the epithelial cells shown here are those typically described for CEOT (Pindborg 1955, Chaudhry et al 1962, Anderson et al 1969, Page et al 1975). However, the common appearance of two or more nuclei in these cells might in fact represent lobes of a deeply indented nucleus rather than separate nuclei.…”

“…The finding at the ultrastructural level of both fine filaments and lamina densa material corresponding to the eosinophilic masses appearing in CEOT has previously been reported (Anderson et al 1969, Page et al 1975 and is discussed in more detail by El-Labban et al 1984.…”

“…More recently it has been shown (Matsumura et al 1971) that, like the cells of the stratum intermedium, the cells of the CEOT are rich in alkaline phosphatase. Other authors (Chaudhry, Holte & Vickers 1962, Anderson, Kim & Minkowitz 1969 have suggested that the tumour may arise from the oral epithelium.…”