A comparative study of generic stains for carcinoid secretory granules

Abstract

Generic stains for secretory granules in carcinoid tumors often yield inconsistent and unpredictable results. These techniques have been modified and new ones devised. Very few studies comparing the efficacy of the various methods have been published to determine which method would most consistenly demonstrate carcinoid granules, a battery of 6 stains were applied to 73 [human] tumors, all morphologically identified as carcinoids, from various sites (17 pulmonary, 13 small intestinal, 20 appendiceal, 18 rectal, 5 miscellaneous). Stains employed included 4 argyrophil (Sevier-Munger, Grimelius, Pascual, Churukian-Schenk), 1 argentaffin (Fontana-Masson) and 1 non-silver technique (lead hematoxylin). Of the 73 carcinoids, 97% stained positively with the Churukian-Schenk 82% with the Pascual, 79% with the Grimelius,74% with the Sevier-Munger, 67% with lead hematoxylin and 51% with the Fontana-Masson technique. The 2 cases negative by the Churukian-Schenk technique were also negative with all other stains; this technique most consitently demonstrated secretory granules in carcinoids, including all 18 rectal tumors. The Churukian-Schenk method achieves its superior results by reducing background staining and nonspecific precipitation to a level that permits sparse, small granules to be readily identified. In control sections of normal mucosa and in some tumors, this stain revealed more than 1 population of argyrophil cells as identified by the size, color and staining intensity of the granules.