Papillary adenocarcinoma of minor salivary gland origin in a child.

A papillary adenocarcinoma with metastasis occurred in a 5-year-old child. The neoplasm arose on the anterolateral sublingual aspect of the tongue and metastasized to a submandibular lymph node. Histologically, the tumor contained broad glandular papillary projections. The tumor cells were cuboidal and had vesicular, "ground glass" nuclei. Colloidlike material was found within the stroma and lumen of the glands. To determine whether the papillary adenocarcinoma was of minor salivary gland or ectopic thyroid in origin, ultrastructural, histochemical, and immunohistochemical techniques were applied to make this clinically important distinction. Ultrastructural and immunohistochemical studies did not indicate the site of origin. Histochemical methods, however, demonstrated the colloidlike material to be sulfated mucopolysaccharide, which was nonreducible by ferric ferrocyanide. These histochemical properties and the anterolateral location identified the tumor as salivary gland in origin.