Strumal carcinoids of the ovary. An immunohistologic and ultrastructural study.

A series of six ovarian strumal carcinoids was examined. The presence of thyroid follicular epithelium was conclusively proved by the presence of follicular cells immunohistochemically positive for thyroglobulin, and by the ultrastructural identification of non-neuroendocrine cells with features of thyroid epithelium lining the follicles. Progressive replacement of thyroid epithelial cells by carcinoid cells accounts for the predominance of neuroendocrine granule-containing cells and the scarcity of thyroid epithelial cells lining many of the follicles. A variety of neuroendocrine hormones and other immunoreactive substances was demonstrated within carcinoid cells, including somatostatin (five cases), chromogranin (five cases), serotonin (five cases), glucagon (four cases), insulin (two cases), and gastrin (one case). Only one case contained calcitonin-positive cells. None were carcinoembryonic antigen-positive or had amyloid deposits. The carcinoid element in five cases stained positively for prostatic acid phosphatase. While strumal carcinoid shares some features with medullary carcinoma of the thyroid gland, it has sufficient differences to warrant a separate designation.

Strumal carcinoid of the ovary. Ultrastructural and immunohistochemical study.

Strumal carcinoid of the ovary with mucinous cystadenoma of borderline malignancy is reported. A colloid-like material in the follicular structure contained thyroglobulin which was immunohistochemically demonstrated to confirm the thyroid element, whereas the carcinoid component, which showed argyrophilia and displayed neurosecretory granules, revealed an insular or trabecular structure. This confirmed the presence of colloid filled thyroid epithelium intimately admixed with the carcinoid. Electron microscopy revealed carcinoid cells expanding toward the inner layer of the follicles but thyroid epithelium almost always stretched its thin cytoplasmic processes to cover the colloidal lumen. No calcitonin was demonstrated but CEA was seen in some cells of the carcinoid. No amyloid was detected.

Ovarian strumal carcinoid: immunohistochemical, ultrastructural, and clinicopathologic observations.

A review of 13 ovarian strumal carcinoids in the files of the Armed Forces Institute of Pathology has established further evidence that these tumors have both endocrine and neuroendocrine differentiation. The two functional routes of differentiation occur even within individual tumor cells. Immunohistochemical reaction for thyroglobulin was positive in the strumal regions of all 12 cases tested. This positivity was also present in transitional zones where the thyroid follicles merged with nests of carcinoid cells. Electron microscopy performed in six cases showed cells with neuroendocrine granules in the thyroid follicles; these cells resemble the C-cells of the normal thyroid gland. An immunoperoxidase reaction for calcitonin, however, revealed no positivity in any of the cells corresponding to the neuroendocrine cells within the follicles or those in the carcinoid component. Variable positivity for serotonin was observed, however. It is proposed that cells within the struma that have morphologic similarities to the C-cells of the thyroid give rise to the carcinoid component. These cells appear capable of producing thyroglobulin as well as neuroendocrine granules.

Evidence of hybrid cell of thyroid follicular cell and carcinoid cell in strumal carcinoid.

A strumal carcinoid associated with mature cystic teratoma of the ovary in a 59-year-old was investigated immunohistochemically and electron microscopically. Histologically it was composed largely of trabecular and partly of insular carcinoid and individual thyroid follicles. Intensive argyrophilia was shown in both the cells of carcinoid tumor and follicular structure. Thyroglobulin was strongly positive in the follicular lining epithelium and weakly positive in the carcinoid cells adjacent to the follicular area. Immunoreactive cells for somatostatin and prostatic acid phosphatase were strongly detected in the carcinoid area and gradually blended to the follicular epithelium. Methionine-enkephalin, glicentin, and pancreatic polypeptide were focally detected in the carcinoid area. Whereas calcitonin-positive cells were sparsely observed in the follicular area, carcinoembryonic antigen and serotonin were absolutely negative. Electron microscopic findings revealed abundant neurosecretory granules, microfilaments, and colloid-like droplets in the same cells. We suggest that these hybrid cells are the origin of strumal carcinoid.

Histology, ultrastructure, and immunohistochemistry of strumal carcinoid: a case report.

A case of ovarian strumal carcinoid was studied by histochemistry, electron microscopy, and immunocytochemistry. The thyroid component of the tumor was micro-macrofollicular, whereas the carcinoid areas had a trabecular growth pattern. Carcinoid cells contained argyrophilic, dense-core secretory granules and were immunopositive for serotonin but not for calcitonin, somatostatin, or thyroglobulin. Follicular thyroid cells were positive for thyroglobulin, and were negative for calcitonin and somatostatin. Thyroglobulin and serotonin-containing cells were present in microfollicles adjacent to areas of trabecular carcinoid and struma ovarii. The data suggest that strumal carcinoids develop in close association with struma ovarii and represent a subset of ovarian teratomas. Current hypotheses on the cell of origin of strumal carcinoids are reviewed.

Ovarian strumal carcinoid. An immunocytochemical and ultrastructural study of two cases.

Examination by immunoperoxidase methods showed that two strumal carcinoids contained thyroxine in the follicular epithelium and colloid. Ultrastructure showed features of thyroid epithelia. Granule-containing cells replaced some follicular epithelial cells at the colloid interface. The morphology of the granules of these cells resembled those of C-cells and foregut-hindgut carcinoids. Transition between thyroid and carcinoid occurred by proliferation of interfollicular cells which subtly formed trabecular structures. Immunoperoxidase for calcitonin was positive both in the interfollicular cells of one tumor and in cells near the transition from thyroid to carcinoid pattern of the other. We conclude that thyroid tissue is a proven component of strumal carcinoid but that follicular epithelial cells may be replaced by granule-containing parafollicular cells. We suggest that the transition from thyroid to carcinoid is accomplished through an intermediate stage of calcitonin-positive cell proliferation. We emphasize, however, that these neoplasms are types of teratomas which may show several forms of differentiation. The tumor of one patient had mid-gut carcinoid elements and represents the first described strumal carcinoid with the carcinoid syndrome.

Strumal carcinoid of the ovary: an analysis of its components.

A strumal carcinoid of the ovary was studied by light and electron microscopy. Thyroglobulin was demonstrated within the strumal element by immunofluorescence, thus establishing the identity of the thyroid tissue. The carcinoid fulfilled the light and electron microscopic criteria for a mixed insular and trabecular example of this tumor. Intermediate zones between the two tissue elements showed mixed characteristics. No amyloid was found. Immunoreactive calcitonin was demonstrated in the tumor, suggesting the presence of C-cells or medullary carcinoma of the thyroid.