Identification of Germline FOXE1 and Somatic MAPK Pathway Gene Alterations in Patients with Malignant Struma Ovarii, Cleft Palate and Thyroid Cancer

Germline variants in the FOXE1 transcription factor have been associated with thyroid ectopy, cleft palate (CP) and thyroid cancer (TC). Here, we aimed to clarify the role of FOXE1 in Portuguese families (F1 and F2) with members diagnosed with malignant struma ovarii (MSO), an ovarian teratoma with ectopic malignant thyroid tissue, papillary TC (PTC) and CP. Two rare germline heterozygous variants in the FOXE1 promoter were identified: F1) c.-522G>C, in the proband (MSO) and her mother (asymptomatic); F2) c.9C>T, in the proband (PTC), her sister and her mother (CP). Functional studies using rat normal thyroid (PCCL3) and human PTC (TPC-1) cells revealed that c.9C>T decreased FOXE1 promoter transcriptional activity in both cell models, while c.-522G>C led to opposing activities in the two models, when compared to the wild type. Immunohistochemistry and RT-qPCR analyses of patients' thyroid tumours revealed lower FOXE1 expression compared to adjacent normal and hyperplastic thyroid tissues. The patient with MSO also harboured a novel germline AXIN1 variant, presenting a loss of heterozygosity in its benign and malignant teratoma tissues and observable β-catenin cytoplasmic accumulation. The sequencing of the F1 (MSO) and F2 (PTC) probands' tumours unveiled somatic BRAF and HRAS variants, respectively. Germline FOXE1 and AXIN1 variants might have a role in thyroid ectopy and cleft palate, which, together with MAPK pathway activation, may contribute to tumours' malignant transformation.

Metabolic Response by 18F-FDG PET/CT in Metastatic Malignant Struma Ovarii Treated With Targeted Therapies

Malignant struma ovarii (MSO) is a rare malignant ovarian tumor, histologically identical to differentiated thyroid cancers. Given the rarity of this disease, there are no treatment guidelines, and the place of imaging for response assessment remains controversial. We report a metabolic response assessed by F-FDG PET/CT in a 71-year-old woman with radioiodine-refractory metastatic MSO treated by targeted therapies (first line with lenvatinib and second line with pazopanib). This case of exceptional response also highlights the usefulness of F-FDG PET/CT for therapeutic assessment of targeted drugs in such a rare clinical entity of malignant MSO.

Strumal Carcinoid of the Ovary: An Immunohistochemical and Electron Microscopic Study

A case of strumal carcinoid of the ovary is reported. The follicles contained T4-immunoreactive substance, whereas the carcinoid component of the tumor had a trabecular structure and showed argyrophilic elements. Pancreatic-polypeptide and enteroglucagon were localized in these cells by an immunocytochemical method. The same cells displayed small electrondense endocrine-like granules. A common precursor for the thyroid and carcinoid components is postulated.

Coexistence of malignant struma ovarii and cervical papillary thyroid carcinoma

CONTEXT

Struma ovarii is an uncommon monodermal teratoma in which thyroid tissue is the predominant element. Malignant transformation of struma ovarii is an even rarer occurrence.

CASE PRESENTATION

We describe a 42-year-old woman who underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy for a symptomatic left pelvic mass. Histology revealed malignant struma ovarii with classical papillary thyroid carcinoma expression. Ultrasonography of the cervical neck showed thyroid micronodules and a dominant 1-cm nodule in the left thyroid lobe. As the ovarian tumor was large, the patient underwent a total thyroidectomy with the intention of administering ¹³¹I therapy in an adjuvant setting. Histology of the cervical thyroid gland revealed bilateral multifocal papillary thyroid carcinoma with extrathyroidal extension and perithyroidal lymph node metastasis.

METHODS

Morphological (microscopy), immunohistochemical (Hector Battifora mesothelial cell 1, cytokeratin-19, galectin-3), and molecular (BRAF V600E, RAS, RET-PTC) characteristics and clonality analysis of the cervical thyroid and ovarian tumors were explored to distinguish them as separate malignancies.

RESULTS

The thyroid-type tumors from the cervical gland and ovary were discordant in terms of tissue histology and level of cytokeratin-19 expression. The clinical features and tumor profile results supported the independent existence of these two embryologically related, although topographically distinct, malignancies.

CONCLUSION

Our findings provided support for synchronous, albeit distinct, primary tumors in the ovary and cervical thyroid. "Field cancerization" and early genomic instability may explain multifocality in all thyroid-type tissue. In this regard, patients with malignant struma ovarii should undergo imaging of their thyroid gland for coexisting disease and thyroidectomy recommended for suspected malignancy or in preparation for radioiodine therapy.

Struma ovarii simulating ovarian sertoli cell tumor: a case report with literature review

Struma ovarii, as a monodermal variant of ovarian teratoma, constitutes about less than 3% of ovarian teratomas. It is difficult to be macroscopically recognized. Multiple appearances under microscope serve as another reason to mislead the accurate pathologic evaluation. Here, we report an unusual case of struma ovarii occurred in a 77 years old woman, which is currently known as the oldest age for this disease. The frozen section morphologically showed sex cord like elements and was suspicious for a sex-cord stromal tumor, probably a Sertoli cell tumor. Final pathological diagnosis was confirmed as struma ovarii based on the typical morphologic thyroid follicles and immunohistochemical staining results.

Peptide YY producing strumal carcinoid tumor of the ovary

BACKGROUND

Primary ovarian carcinoid tumor is uncommon and represents less than 0.1% of ovarian malignancies. The strumal carcinoid may be complicated by carcinoid syndrome induced by peptide YY (PYY).

CASE REPORT

We describe a 45-year-old woman with a bilateral ovarian tumor diagnosed through periodical gynecological examination. She presented with severe constipation. Right ovarian cyst laparoscopically resected was diagnosed as a strumal carcinoid tumor; the left one was mature cystic teratoma. No metastatic findings were seen macroscopically on the ovarian surface and pelvic peritoneum. Constipation was drastically improved by resecting the tumor. The carcinoid tumor cells were positive for tumor-producing PYY by mRNA analysis.

CONCLUSION

It is important to be aware of this entity in the pathological diagnosis of ovarian tumors, in the presence of any clinical indicator of carcinoid tumor/syndrome, as it carries a markedly better prognosis and clinical outcome in comparison with most other malignant ovarian tumors.

Cytologic differentiation of struma ovarii from other ovarian neoplasms

OBJECTIVE

To present the cytologic findings of struma ovarii and value of cytology and immunocytochemistry (ICC) using thyroglobulin (TGB) and thyroid transcription factor-1 (TTF-1) in evaluation of this unusual ovarian neoplasm, together with the diagnostic pitfalls.

STUDY DESIGN

Intraoperative cytologic findings of 7 patients with struma ovarii are reviewed. Cytologic material of both cystic and solid components was collected intraoperatively. ICC staining was done, and cell block preparation performed on selected cases.

RESULTS

The cases were divided in to 3 groups: group 1--diagnosis of struma ovarii was made by cytology and confirmed by ICC (1 case); group 2--diagnosis was suggestive on cytology or cell block and confirmed by ICC staining (4 cases); group 3--on cytologic diagnosis indistinguishable from other cystic ovarian neoplasms (2 cases). Cytologic findings were typically colloid with mosaic pattern, follicles, follicular cells only, sheets of follicular cells, both colloid and follicular cells, proteinaceous background or degenerated epithelial cells indistinguishable from other cystic ovarian neoplasms.

CONCLUSION

Cytologic findings of struma ovarii are distinct enough to be suggested intraoperatively, and ICC for TGB or TTF-1 is a valuable tool for preoperative fine needle aspiration biopsy and intraoperative diagnosis of this benign ovarian neoplasm.

Follicular variant papillary thyroid carcinoma arising in struma ovarii

Struma ovarii is a rare monodermal ovarian teratoma in which thyroid tissue is the predominant or exclusive element. Malignant transformation is known to occur, usually as classical papillary thyroid carcinoma (PTC). However, the recognition of follicular variant PTC raises the possibility of similar malignancy arising in struma ovarii. We examined 13 cases of struma ovarii to determine if these lesions can exhibit histological, immunohistochemical, and/or molecular features of follicular variant PTC. Ten of these had atypical histology, cytologic features of PTC, and all ten showed diffuse positivity for CK19; eight of these were also positive for HMBE-1. Mutational analysis for BRAF identified no V600E mutations. However, seven of the ten cases with features of follicular variant PTC exhibited a rearranged in transformation (RET)/PTC rearrangement by reverse transcriptase polymerase chain reaction (RT-PCR). The three cases considered to be benign based on histologic and cytologic criteria were negative for CK19 and HBME-1 by immunohistochemistry, and had no evidence of BRAF mutation or ret/PTC-1 and ret/PTC-3 rearrangements. These results indicate that follicular variant PTC can occur in struma ovarii and that such lesions exhibit the same morphologic and immunohistochemical profile as follicular variant PTC in thyroid. The application of molecular testing to verify the diagnosis can be valuable, as these lesions may harbor ret/PTC gene rearrangements.

Expression of thyroid transcription factor 1 (TTF-1) in extra thyroidal sites: papillary thyroid carcinoma of branchial cleft cysts and thyroglossal duct cysts and struma ovarii

The thyroid-associated transcription factor-1 (TTF-1) is a nuclear tissue specific protein, found only in thyroid and thyroid tumors regardless of histologic type as well as in lung carcinomas. Most ectopic thyroid tissue are found along the thyroglossal duct tract and around the bilateral main lobes of thyroid glands. Ectopic thyroid tissue within a branchial cleft cyst is a rare abnormality and papillary carcinoma arising in this tissue is extremely rare. Thyroid tissue may also be found as one of the many components of teratoma, particularly those located in the ovary. The aim of this study is to evaluate, through immunohistochemistry, the expression of TTF-1 in branchial cleft cysts with ectopic normal thyroid tissue, in primary thyroid papillary carcinomas of branchial cleft cysts and thyroglossal duct cysts and in struma ovarii, in order to evaluate the expression of this antigen in extra thyroidal sites.

Malignant struma ovarii: A case report

Malignant struma ovarii is a rare form of the ovarian germ cell tumors. Hence, diagnosis and management of malignant struma ovarii have not been clearly defined. We present the case of a 34-year-old woman with papillary carcinoma arising in struma ovarii. The malignant component of this tumor was detected after laparoscopic removal, and a re-staging operation was performed afterwards. There was no evidence of clinical malignancy or metastases. In this paper, clinical features, treatment guidelines, diagnostic features, and immunohistochemical characteristics of this tumor are reviewed.

Coexisting Brenner tumor and struma ovarii in the right ovary: Case report and review of the literature

A bilateral ovarian tumor composed of mixed Brenner tumor and struma ovarii in the right ovary and mature cystic teratoma in the left ovary, is described. Mixed Brenner tumor and struma ovarii is rare; eight cases are reviewed. In this case, in addition to the typical Brenner tumor and struma ovarii, some nests composed of both Brenner tumor and struma ovarii in one nest were found in the right ovarian tumor. Immunohistochemically, the struma ovarii is stained for thyroglobulin, and Brenner nests showed various degrees of positive stain for thyroglobulin, which is a specific finding. Brenner tumor, in this case, may produce thyroglobulin or have a receptor to thyroglobulin or analog of thyroglobulin. The origin of mixed Brenner tumor and struma ovarii may be germ cell, as described in some literature, or the Brenner tumor may be of a metaplastic nature, although the Brenner tumor is fourfold the size of struma ovarii in the case presented.

Expression of thyroid transcription factor-1 in strumal carcinoid and struma ovarii: an immunohistochemical study

Strumal carcinoid is an ovarian teratoma composed of thyroid tissue and carcinoid, intimately admixed in variable proportions. To further elucidate the histogenesis of strumal carcinoid, the expression pattern of thyroid transcription factor-1 (TTF-1) was evaluated in two cases of strumal carcinoid using immunohistochemical techniques. TTF-1 is a nuclear transcription protein that is selectively expressed in the thyroid and respiratory epithelium, and is thought to be expressed specifically in pulmonary and thyroid neoplasms. While the follicular lining cells of the strumal carcinoid showed positive staining for TTF-1, the carcinoid element was, for the most part, negative. These results confirm that TTF-1 is expressed in the thyroidal element of ovarian teratomas and also provide further evidence that the carcinoid component of the strumal carcinoid bears no relation to thyroidal differentiation.

Amelanotic malignant melanoma arising in an ovarian cystic teratoma: a case report

BACKGROUND

Malignant melanoma arising in a cystic teratoma is extremely rare. We report the clinicopathologic and cytopathologic features of an amelanotic malignant melanoma arising in an ovarian cystic teratoma.

CASE

A 55-year-old woman presented with an asymptomatic right ovarian mass, showing features of cystic teratoma according to preoperative computed tomography and magnetic resonance imaging. The resected teratoma was suspected to include a nonepithelial malignancy in a touch preparation from a solid component. The tumor showed immunoreactivity for Melan-A, S-100 and HMB-45 in the absence of melanin granules, which established the diagnosis of amelanotic malignant melanoma arising in an ovarian cystic teratoma.

CONCLUSION

Cytopathologic findings from touch preparations and immunohistochemical staining are useful for the diagnosis of amelanotic malignant melanoma arising in an ovarian cystic teratoma.

Strumal carcinoid of ovary. A case report with immunohistochemical investigations

Clinical, histological and immunohistochemical findings in a rare ovarian tumor--strumal carcinoid--are presented. Neuropeptides detected by immunoreactions revealed the origin of tumor cells from the midgut. Immunohistochemical reaction revealed parathyroid hormone-related protein (PTHrp) in the carcinoid cells. After surgical resection of the tumor a decrease in serum calcium level was observed.

Ovarian strumal carcinoid with severe constipation: immunohistochemical and mRNA analyses of peptide YY

Functioning ovarian carcinoid tumors are well known to cause carcinoid syndrome. Recently, strumal and trabecular ovarian carcinoid tumors are reported to cause severe constipation possibly because of tumor-producing peptide YY (PYY). We studied a case of primary ovarian strumal carcinoid who had had severe constipation until the tumor was removed by surgical operation. Immunohistochemically, many tumor cells were strongly positive for PYY. By Northern blot and reverse transcription polymerase chain reaction analyses, PYY mRNA was expressed in a complete form as detected in normal human colon mucosa. From these findings, an ovarian strumal carcinoid is strongly suggested to express complete PYY mRNA and therefore complete PYY protein that results in severe constipation.

A study of human calcitonin in an ovarian carcinoid and ovarian cancers

High concentration of human calcitonin (hCT) was found in an ovarian carcinoid by radioimmunoassay. The hCT value was not affected by the presence of protease inhibitors. To confirm the presence of hCT in an ovarian carcinoid, hCT was isolated by the Baghdiantz method. The molecular weight of the ovarian hCT was determined using Sephadex G-75 gel filtration. Though the molecular weight of the ovarian hCT was variable, 90% corresponded to that of the authentic hCT. The carcinoid cells were examined by immunoperoxidase techniques. Those composed of strumal and trabecular structure were all argyrophilic, but hCT was only found in strumal structure. Significant concentrations of hCT were also found in ovarian cancers.

Malignant struma ovarii treated by ovariectomy, thyroidectomy, and 131I administration

A 36-year-old woman presented with an intraperitoneally disseminated malignant struma ovarii, diagnosed by histopathology and 131I scintigraphy. The serum thyroglobulin level was elevated, and immunoperoxidase staining for thyroglobulin was positive for disease both in the tumor cells lining the follicles and in the colloid. The patient was treated successfully by a bilateral ovariectomy followed by a total thyroidectomy and administration of radioactive iodine. The clinical behavior and the presence of thyroglobulin in both serum and tumor tissue demonstrate the similarity between neoplastic thyroid tissue in the ovary and in the thyroid gland.

Immunocytochemical localization of calcitonin-producing cells in a strumal carcinoid with amyloid stroma

A nonfunctioning strumal carcinoid arising in a 49-year-old woman was studied by histochemical and immunocytochemical techniques. All tumor cells, irrespective of their architectural arrangement, showed properties of neuroendocrine-programmed cells, without any evidence of thyroid follicular cell differentiation. Foci of calcitonin-producing C-cells were demonstrable by immunocytochemical technique and were closely associated with areas of amyloid stroma of the tumor. Efforts at localization of insulin and gastrin within the tumor cells gave negative results. While the results in the present case offer additional support for an APUD cell origin of strumal carcinoids, the presence of the calcitonin-producing C-cells within the tumor raises interesting histogenetic possibilities as to whether these lesions are derived from C-cells or represent an ovarian carcinoid with foci of C-cell differentiation.

Calcitonin secreting struma-carcinoid tumor of the ovary

The ultrastructure of strumal carcinoid tumors at times may reveal a far more complex structure than can be ascertained from light microscopy. It may at times be indistinguishable from medullary carcinoma of the thyroid gland. Both tumors appear to be capable of producing 5-hydroxyindolacetic acid and calcitonin. The common shared biologic and ultrastructural features suggest a common origin, from neuroectodermal cells.

Benign and malignant struma ovarii

Three cases of struma ovarii are reported, two of which were benign, and one which was malignant. Immunoperoxidase studies confirmed that the tumors secreted triiodothyronine and thyroxine, but no carcinoembryonic antigen nor alpha-fetoprotein. In the case of the malignant struma ovarii, the patient's thyroid was histologically normal, and thus the possibility of a metastasis to the ovary from a primary thyroid carcinoma was excluded.