Hyaline Metamorphosis is a conversion of cells and intercellular substance into hyaline material.

The cells of the connective tissue are most frequently involved, but epithelial and muscle cells may be affected.

The Hyaline Material

The Hyaline Material occurs in the form of granules, is glistening and waxy, and with Van Gieson's method stains intensely red. Has no specific action with iodin.

It is at times scarcely distinguishable from amyloid metamorphosis.

It is found as a result of infectious diseases, septic processes, in chronic intoxications, such as lead-poisoning, and in new growtns. its formation is probably dependent upon some malnutrition of the tissues. Generally this form of degeneration is not sufficiently extensive to be recognized by the naked eye.

Fig. 8.-Hyaline Degeneration of the Reticulum of a Lymph-gland in Tuberculosis. X 280 (Durck).

Among the lymphocytes are seen single reticular fibers, which are greatly thickened and transformed into shining, homogeneous, non-nucleated bars (I).

The most common site is in the endothelial and subendo-thelial tissues of the blood-vessels. The lumen will be narrowed or obliterated according to the extent of the thickening of the wall.

It also frequently occurs in the interstitial tissues, as between the renal tubules, between muscle-fibers, hepatic cells, and in the reticulum of lymph-nodes (Recklinghausen's degeneration). A third site is within the cells, particularly those of mesodermic origin.

It is either formed within the cell or. being formed elsewhere, has been brought to and deposited within the cell.