Chondroid chordoma. Electron-microscopic study of two cases

Area of Science:

• Pathology
• Oncology
• Electron Microscopy

Background:

• Chondroid chordoma is a rare tumor with features of both chondroma and chordoma, typically found in the spheno-occipital area.
• It shares clinical and histological traits with classic chordoma and chondrosarcoma, but generally has a better prognosis.
• No prior ultrastructural studies existed for chondroid chordoma.

Observation:

• Two cases of chondroid chordoma were examined using electron microscopy.
• Common ultrastructural features with chordoma and chondrosarcoma included dilated rough endoplasmic reticulum, glycogen aggregates, and fibrillogranular matrix.
• Unique findings in chondroid chordoma included tonofilament desmosome complexes and crystalline tubular structures within the rough endoplasmic reticulum.

Findings:

• Ultrastructural analysis revealed specific features differentiating chondroid chordoma from cartilaginous tumors.
• The presence of well-formed tonofilament desmosome complexes was noted.
• Distinctive crystalline, tubular structures within the rough endoplasmic reticulum were observed for the first time.

Implications:

• These ultrastructural findings may aid in differentiating chondroid chordoma from classic chordoma, which can be challenging at the light-microscopic level.
• The identified tubular structures could serve as a valuable diagnostic marker.
• This study provides novel ultrastructural insights into chondroid chordoma, contributing to its understanding and classification.