Studies in urolithiasis. III. Electron optical investigation on the morphology of the colloidal matrix of urinary calculi.

An electron optical investigation of the morphology of the colloidal matrix of renal and vesical urinary calculi revealed the presence of several morphologic forms hitherto unknown. Earlier light microscopic studies indicated that the matrix exists either as fibrils or as an amorphous matrix. The electron micrographic scanning of specimens of calculi revealed the following matrix morphologies: (i) flaky, (ii) serrated, (iii) perforated (globular), (iv) hollow tubular, (v) fibrillar, (vi) cylindrical, and (vii) pear-drop shaped. Crystalline matter was not associated with flaky and serrated matrix particles. However, some matrix particles of perforated (globular), fibrillar, and cylindrical morphologies were found to be calcified.