Primary papillary psammomatous adenocarcinoma of the umbilicus.

The histological and ultrastructural features, as well as the immunoreactivity of one case of uncommon primary papillary and psammomatous adenocarcinoma of the umbilicus are studied in the present work. The observations have been undertaken in a nine-year follow-up, and have included the primitive tumour, two local recidives, and inguinal lymphatic metastasis on two occasions. Papillary structures, numerous psammoma bodies, as well as weak and focal positive reactions to CEA and cytokeratin were present in all the tumours. Since these features and their ultrastructural characteristics were identical to primary papillary serous neoplasias of the peritoneum and ovarium, the hypothesis of an origin in coelomic remnants is considered.