Histologic spectrum of struma ovarii.

Six cases of struma ovarii, including two with associated carcinoid, with unusual microscopic features are described. The patients' age ranged from 22 to 50 years. The patients were clinically euthyroid. The largest tumour was 10 cms. in great dimension. All tumours were unilateral. Microscopically various changes observed in a non-neoplastic thyroid gland were observed in the struma including Hashimotos thyroiditis and goitrous change. Adenomatous foci with microfollicles were observed in one case. A trabecular carcinoid admixed with mucinous glands lined bygoblet cells which were argyrophilic was seen in two of the neoplasms. This finding is rare and has been reported only once before. In conclusion it is important for a pathologist to be aware of the changes that may be associated with struma ovarii, so as not to confuse it with other neoplasms. A careful search for typical thyroid follicles, or other components of a dermoid help to arrive at a diagnosis.