EM proves invaluable in the confirmation of chordoma in the sacral mass of a middle-aged man.

A case of a 47-year-old male with a sacral spine mass was investigated by histology, immunohistochemistry (IHC), and electron microscopy (EM). The light microscopy of the first core biopsy revealed scant cellularity with spindle and round cells with eosinophilic cytoplasm within a fibromyxoid background. Immunostaining with pancytokeratin, cytokeratin 19, and S100 was nonspecific. Another biopsy was attempted to obtain a more definitive diagnosis. Light microscopy of the second core had scant cellular material. However, the tissue was specifically requested for ultrastructural evaluation and revealed features diagnostic of chordoma. After definitive diagnosis, radical resection of the mass was performed. This case illustrates how EM was instrumental in the definitive diagnosis before radical resection in a case that was not clear by hematoxylin and eosin (H&E) and IHC alone.

Morphometric evaluation of the first sacral vertebra and the projection of its pedicle on the posterior aspect of the sacrum.

STUDY DESIGN: This study directly measured the dimensions of the first sacral vertebra based on dry bony specimens. OBJECTIVES: To measure the dimensions of the S1 pedicle, vertebral body, and spinal canal, and determine the projections of the S1 pedicle on the posterior aspect of the sacrum. SUMMARY OF BACKGROUND DATA: Sacral screw fixation remains a challenging clinical problem because of the unique anatomy of the first sacral vertebra. The anatomic data of S1 have rarely been described in the literature. METHODS: Sacrums from 50 carefully prepared bony spines were used. Linear measurements included the dimensions of the vertebral body, spinal canal, and pedicle. Pedicle width was measured in two segments, pedicle zones 1 and 2. Angular measurements of the pedicle relative to the sagittal plane were also included. RESULTS: In pedicle zone 1, the average medial angle of the pedicles was 10.2 degrees for men and 10.7 degrees for women, average width was 10.9 mm for men and 10.4 mm for women, average length of the pedicles was 34.6 mm for men and 34.9 mm for women. In pedicle zone 2, the average medial angle of the pedicles was 39.4 degrees for both men and women, average width was 15.6 mm for men and 14.7 mm for women, average length of the pedicles was 43.7 mm for men, and 41.7 mm for women. The projections of pedicle zones 1 and 2 on the posterior aspect of S1 were determined. CONCLUSIONS: The investigators proposed the concept of pedicle zones 1 and 2. The safer area for S1 pedicle screw insertion was found in pedicle zone 2.

Extraspinal ependymoma in the sacrococcygeal region. A case report with ultrastructural, immunohistochemical and cytophotometric studies.

We describe on a primary, subcutaneous sacrococcygeal ependymoma presenting in a young female patient. Detailed immunohistochemical and electron microscopic examinations were performed. Out of the 40 similar cases reported in literature this is the first in which the determination of DNA content was also used to predict biological behaviour. The tumour proved to be aneuploid with low proliferative capacity in spite of absent histological signs of malignancy. It is suggested that DNA determination may be helpful in establishing prognosis and that it may contribute to a better understanding of the biological behaviour of this tumour.

[Electronic microscopic study of a sacral chordoma. Characterization of various development stages of the tumor cells]. / Etude au microscope électronique d'un chordome sacré. Caractérisation de diverses étapes évolutives des cellules tumorales.

The electron microscopic study of a sacral chordoma, the cells of which contain variable amounts of glycogen, allowed to characterize different stages in the evolution of the tumoral cells. The young cells contain almost no glycogen ; progressively it becomes more abundant and fills up almost the whole cytoplasm. At the end of the evolution glycogen disappears while the cell becomes vacuolated. This suggests that enzymatic lysis of this polysaccharide could be the cause of the vacuolation which finally produces the physaliferous cell. Comparison between the cells of the chordoma and those of the normal notochord shows some morphological similarities in the development of these cells. These different data may be useful for a classification of the various types of chordomas.