PAPILLARY NEOPLASM OF THE ENDOLYMPHATIC S AC - A CLINICOPATHOLOGICAL AND IMMUNOCYTOCHEMICAL STUDY OF 3 CASES

Glandular tumors involving the mastoid and the middle ear are rare, an d distinguishing between adenoma and adenocarcinoma remains difficult. Among these latter lesions, two distinct patterns are accepted. One o f them, the papillary form takes a more agressive course with wider re gional spread and must be separated from the other type, the middle ea r carcinoma. Its microscopic appearance and clinical course have been extensively described by Heffner who considered it as ''low-grade aden ocarcinoma of probable endolymphatic sac origin''. A few cases have be en associated with von Hippel-Lindau disease. Three cases of papillary adenocarcinoma of endolymphatic sac origin are reported. One concerne d an isolated tumor, the two others were associated with von Hippel-Li ndau disease. Their clinical, pathological and immunohistochemical dat a are presented.