Asbestos bodies in pulmonary hilar lymph nodes

Asbestos bodies (AB) have long been recognized in light microscopic (LM) sections of pulmonary hilar lymph nodes (LN) from patients with asbestos-related diseases, but the presence of AB on LM has not been correlated with the lung AB burden. The purpose of the present study was to determine whether AB in histologic sections of LN are indicative of heavy lung asbestos burdens. Twenty cases (17 with asbestosis, 15 with carcinoma of the lung, and two with malignant pleural mesothelioma) with at least one AB on a hilar LN section were identified. Bleach digestion of lung tissue in 15 cases demonstrated a median of 24,000 AB/g by LM and 44,000 AB/g by scanning electron microscopy. Digestion of hilar nodes demonstrated 21,800, 15,500, and 3,200 AB/g by LM in three cases which had lung burdens of 22,000, 481,000, and 5470 AB/g, respectively. A fourth LN specimen contained 322,000 AB/g in a case with no lung available to digest. Mean AB lengths in the LN in three cases were 48, 45, and 27 microns. Fourteen control cases of men over 50 without known asbestos exposure or asbestos-related disease had no AB in LN sections even after staining for iron. Among fourteen patients with parietal pleural plaques and an elevated lung asbestos body content, AB were observed in iron-stained LN sections in only two cases. These two patients had 3240 and 610 AB/g lung tissue, respectively (normal range 0 to 20 AB/g). We conclude that the finding of AB on a histologic section of hilar LN is generally indicative of a heavy lung AB burden.(ABSTRACT TRUNCATED AT 250 WORDS)