Familial occurrence of small-cell XXXX .

@entity43 @entity1 @entity4153 @entity2741 @entity5
To our knowledge, familial occurrence of small-cell @entity43 in first-degree relatives has not been described before. We studied two separate cases of @entity4153 in a 21-year-old @entity1 and in her 40-year-old mother, both of whom died of disseminated disease. Both @entity5 were studied with immunohistochemistry, using a variety of antibodies, and with flow cytometry. Microscopically, the @entity5 in the daughter was of the usual small-cell type, while that of her mother belonged to a large-cell variety. Immunohistochemically, both @entity5 showed some degree of epithelial differentiation but also expressed reactivity to some other antigens, most notably to smooth-muscle actin and muscle-specific actin. Both @entity5 showed a diploid DNA pattern and low S-phase fraction with flow cytometry. Neither of the cases expressed @entity2741 . @entity4153 may appear as a small-cell or large-cell variety in a familial setting. A diploid DNA pattern appears to be characteristic. Because this @entity5 was first reported relatively recently, the frequency of its familial occurrence is not known.
