Ovarian strumal carcinoid tumor with amyloid stroma--report of a case with 20-year follow-up.

We report a case of strumal carcinoid tumor arising in the left ovary of a 20-year-old woman. Histologically, microfollicular, solid, and trabecular areas were present, and amyloid stroma was demonstrated. Many cells contained argyrophilic granules, and thyroglobulin and calcitonin were demonstrated immunohistochemically in several areas. Ultrastructurally the cells resembled thyroid follicular cells and contained neurosecretory granules. It is concluded that strumal carcinoid is of endodermal origin, and shows evidence of thyroid and C-cell differentiation.