Angioimmunoblastic lymphadenopathy. Fine structure of the lymph nodes by correction of light and electron microscopical findings.

Angioimmunoblastic lymphadenopathy was studied prospectively in 5 patients by correlation of light and electron microscopy of biopsy material obtained from lymph nodes, prior to any substantial therapy. The fine structure of this lymphoproliferative disease revealed various patterns of cellular composition: there was a predominance of lymphocytes, immunoblasts, epithelioid or plasmacytoid cells or mixed cellularity in the lymph nodes. The conspicuous vascular changes consisted or arborization of postcapillary venules, a thickening of the basement membranes and swelling of the endothelial cells. The remarkable eosinophilic or acidophilic debris-like interstitial and pericapillar deposits showed filamentous finely dispersed material containing wide-spacing collagen fibers intermingled with normal collagen, but no fragments of disintegrated cells. Two of these 5 patients developed malignant lymphomas of the Hodgkin-type after 13 months, and of the Non-Hodgkin-type after 7 months. At the time of first biopsy, however, no characteristic alteration of the fine structure of the lymph nodes disclosed evolution towards malignancy.