Paraffin embedding technique for specimens obtained by vitrectomy.

Histologic and immunohistochemical preparation of pathologic fluids containing cellular material is difficult, because the techniques are limited by the amount of cellular material. Similar problems limit the preparation of vitrectomized material. Cytopreparatory techniques, including millipore filter and celloidin bag cell block, have been introduced since 1980 for diagnostic vitrectomies. These techniques are limited by the fact that the specimens cannot be stained using different histologic and immunohistochemical techniques. A second disadvantage of these techniques is that long-term storage of obtained material for later histologic evaluation is not possible. Direct paraffin embedding of vitrectomized specimens is possible, but specimens with low cell numbers are difficult to prepare. Kawan et al introduced a brush cell block technique for diagnosis of bronchial neoplasms, in which histologic evaluation of the tissue can be performed with a small amount of aspirated cells. Herein, we introduce a modification of the technique by Kawan et al to embed vitrectomized material in paraffin.