Lympho-Epithelioma of the Parotid Gland

Abstract

It has long been recognized that the region of the parotid gland is the site of a great variety of tumors of complex structure containing, for example, glands of various types lined with squamous, cylindrical, or flattened epithelium, large areas of small undifferentiated cells, which in general are considered to be remnants of aberrant parotid tissue, cartilage, and even, as Prudden has reported, striated muscle. The proportion of the solid and glandular structures varies greatly in different tumors. Some are composed almost wholly of glands lined with high cylindrical epithelium secreting mucus, the so-called cylindromata. In others the glands are lined with a flattened or indifferent epithelium, apparently not secreting much material. In this latter group may be placed the rare lympho-angiomas of the parotid. Another group is composed of the so-called adenolymphomas, containing cysts lined with high columnar epithelium and surrounded by lymphoid tissue (Fig. 1). True sarcomata, both of the lymphoid and spindle-cell type, are seen, and finally carcinomata may occur. Most of the latter are of the squamous-cell variety; some are adenocarcinomas with much mucus both in the primary growth and in metastases; others may repeat the undifferentiated type of cell which so often composes the ordinary mixed or complex tumors of the salivary gland.