Epidermal inclusions in abdominal lymph nodes. Report of two cases studied immunohistochemically.

Abdominal lymph nodes from men aged 48 and 62 years with gastric adenocarcinoma were examined histologically. A few of the lymph nodes contained epidermal epithelium, although there was no metastasis. Scattered squamous epithelial nests and epidermal cysts were found within the lymph nodes, and small amounts of pancreatic tissue were present adjacent to the epidermal inclusions. Some squamous cell nests showed cyst formation, and some others showed squamous cell nests together with mucin-containing cells forming luminal structures. Immunohistochemically, the squamous cell nests stained weakly for CA19-9 but were negative for CEA or CA125. These lesions were considered to be similar to lymphoepithelial cysts of the pancreas.