Uses and contributions of diagnostic electron microscopy in surgical pathology: a study of 20 Veterans Administration hospitals.

Although the capability of electron microscopy to contribute to histopathologic diagnosis in selected instances, e.g., renal biopsies and biopsies of certain tumors, is generally recognized, its contribution in a broader range of surgical pathology accessions is not well established. To gain further information concerning this aspect of the use of electron microscopy, 7,193 surgical pathology reports, 290 (4 per cent) of which included electron microscopic findings, were analyzed; these reports represented all such accessions during the same single month at 20 VA medical centers. It was found that malignancies constituted 62 per cent of the lesions examined by electron microscopy but only 20 per cent of the total number of surgical cases examined by light microscopy. It was also found that the distribution of specimens by tissue site of origin differed considerably for specimens examined by electron microscopy and light microscopy; positive contributions of electron microscopy to diagnosis were found in 146 of the 290 electron microscopy cases (50 per cent), with higher percentages found in malignancies and in certain tissue site subsets (lower respiratory tract, soft tissue, kidney, skin, and lymph nodes with metastases); failure to examine some specimens (lung metastases to lymph nodes or other tissues and endobronchial biopsy specimens) suggests slight, but common, underutilization of electron microscopy in diagnosis.