Predominant Brenner Tumor Combined with Struma Ovarii Containing a Papillary Microcarcinoma Associated with Benign Peritoneal Strumosis: Report of a Case and Histologic Features

Brenner tumor and struma ovarii, two uncommon ovarian tumors arising alone or together with dermoid cysts or adenomas, are both rare entities. Both tumors rarely become malignant and rarely metastasize. Few published reports describe coexisting Brenner tumor and malignant struma ovarii. Patients in whom these malignancies coexist only occasionally have peritoneal spreading, strumosis, or a history of thyrotoxicosis. The patient we describe, a 74-year-old woman, presented with a 2 months’ history of lower abdominal pain and episodic intestinal subocclusion due to a complex pelvic mass. The mass consisted predominantly of a Brenner tumor associated with struma ovarii containing a single small island of thyroid tissue that had undergone malignant transformation into a well-differentiated papillary carcinoma and also normal thyroid tissue that had spread to the peritoneum. The patient underwent radical surgical treatment and after 7 years follow-up is disease free.     

RAS Mutation-Positive Follicular Variant of Papillary Thyroid Carcinoma Arising in a Struma Ovarii

Struma ovarii is an ovarian mature teratoma composed exclusively or predominantly of thyroid tissue. Malignant transformation of struma ovarii is rare and poorly understood, although this process is thought to be similar to carcinogenesis in malignant tumors of differentiated thyroid tissue originating in the thyroid gland. Genetic alterations in the mitogen-activated protein kinase pathway, including mutations of BRAF, RAS, and RET genes, have been implicated in the development of differentiated thyroid carcinoma arising in the thyroid gland. We report here a case with RAS mutation detected in a malignant struma ovarii. The patient is a 38-year-old female who had a 2.4 cm ovarian cyst noted incidentally on a first trimester ultrasound. She proceeded to ovarian cystectomy post-delivery, with pathologic examination detecting a papillary thyroid carcinoma, follicular variant, arising in a cystic teratoma. The tumor was tested for BRAF, RAS, and RET/PTC mutations. HRAS codon 61 mutation was identified. This is the first report of RAS mutation detected in the follicular variant of papillary carcinoma arising in a struma ovarii. It provides evidence that tumors developing in this setting involve molecular mechanisms similar to those implicated in tumors developing in the thyroid gland.     

Unilateral malignant struma ovarii in a case of bilateral ovarian teratoma with raised CA-125 level: a rare case with treatment dilemmas

Struma ovarii are specialized form of mature ovarian teratoma comprised predominantly of thyroid tissue (>50%). Most of the struma ovarii are benign; rarely can they undergo malignant transformation. Elevated CA-125 levels with benign struma ovarii have been seen in only 5 cases in literature. The association of malignant struma ovarii and high CA-125 levels with pseudo-Meig syndrome has been reported in only 2 cases in English literature. We describe a case of a 46-year-old multigravida who presented with an abdominal mass and raised CA-125 levels. Radiological investigations revealed bilateral cystic adnexal masses with ossified elements on left side suggesting a teratoma. Intraoperative frozen section and final pathology revealed bilateral teratoma with follicular variant of papillary thyroid carcinoma arising in the left ovary. To the best of our knowledge, this is the first case of malignant struma ovarii in combination with bilateral teratoma. The dilemmas related to preoperative diagnoses with elevated CA-125 levels, mimicking an epithelial ovarian neoplasm; intraoperative frozen section consultation; management and follow-up issues in this rare malignancy are discussed.     

Case report: Malignant struma ovarii

Struma ovarii are specialized teratomas consisting of thyroid tissue with various microscopic features, ranging from benign to malignant. We report a rare form of malignant struma ovarii, composed exclusively of a follicular variant of papillary thyroid carcinoma with capsular invasion, which occurred in a 65-yr-old woman.     

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.     

Real-time analysis of beta- and gamma-catenin mRNA expression in ret/PTC-1 activated and nonactivated thyroid tissues.

Our group has previously demonstrated an association between ret/PTC-1 activation and decreased E-cadherin mRNA levels in papillary thyroid carcinoma. We also observed similarities in the E-cadherin expression profiles of Hashimoto thyroiditis and ret/PTC-1-positive papillary thyroid carcinomas and have hypothesized that ret/PTC-1 activation might cause not only the structural and nuclear peculiarities of PTC but also an immune reaction to thyroid epithelium. The objective of this study was to examine the expression of E-cadherin's ligands, beta- and gamma-catenin, in various thyroid tissue types in the context of ret/PTC-1 positivity using laser capture microdissection and TaqMan (Applied Biosystems, Foster City, CA). One-Step RT-PCR. Beta-catenin mRNA levels were found to be consistently decreased in both papillary and anaplastic carcinomas when compared with a normal/follicular adenoma group. A significant difference in expression levels was observed between papillary and follicular thyroid carcinomas with the latter having elevated mRNA levels of beta-catenin. Gamma-catenin mRNA was decreased in anaplastic carcinomas compared with normal/follicular adenoma groups. A similar expression profile of gamma-catenin as beta-catenin was observed in papillary and follicular carcinomas with the latter once again having higher mRNA levels. These results therefore suggest that although beta- and gamma-catenin may play a role in the progression of thyroid cancer in general, they do not appear to be associated with ret/PTC-1-modulated pathways.     

Malignant struma ovarii: a case report and review of the literature

A 45-year-old woman with papillary carcinoma arising in struma ovarii which involved one ovary without dissemination is presented. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. Histopathological examination revealed malignant struma ovarii of the papillary type. The flow cytometric analysis revealed an hypodiploid DNA content (DNA index:0.67). Since these are rare tumors, there is no universal exact protocol for the treatment and follow-up of patients with malignant struma ovarii. More data are needed to determine the prognosis and management in preferring mode of therapy.     

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.     

Spindle cell transformation of papillary carcinoma: an aggressive entity distinct from anaplastic thyroid carcinoma

Spindle cells are not routinely encountered in the context of thyroid pathology and are most often present in anaplastic thyroid carcinoma, medullary thyroid carcinoma, and benign conditions such as Riedel struma or de Quervain granulomatous thyroiditis. Only a few publications have reported papillary thyroid carcinoma admixed with a prominent spindle cell component. While these tumors are clearly distinct from anaplastic thyroid carcinoma, prognostication as to their oncologic potential is not yet established. We describe a unique case of spindle cell transformation of papillary thyroid carcinoma. The blandness of the spindle cells was so impressive as to dissuade us from a malignant diagnosis on preoperative biopsies. However, this patient unfortunately died shortly after transformation of this papillary thyroid carcinoma. We conclude that this peculiar and rare spindle cell transformation should be regarded as a potentially lethal variant of papillary thyroid carcinoma.     

Intraluminal crystalloids in struma ovarii. Immunohistochemical, DNA flow cytometric, and ultrastructural study

We recently encountered a unique case of follicular variant of papillary carcinoma arising in struma ovarii that contained numerous intrafollicular crystalloids. There was no evidence of capsular or vascular invasion or metastases, though the DNA content of the papillary carcinoma was aneuploid. In contrast, diploid DNA was manifested in the histologically benign thyroid tissue. The nature of the crystalloids and the significance of aneuploid DNA content are discussed.     

Ovarian cystic tumor composed of Brenner tumor and struma ovarii

Ovarian tumor composed only of Brenner tumor and struma ovarii is very rare; only 6 cases have been reported in the English literature, to the best of the author's knowledge. A 66-year-old woman underwent right oophorectomy because of torsion of right ovarian cyst. Macroscopically, the ovarian cyst was hemorrhagic and red. Cystic content was hemorrhagic fluid. Microscopically, the cyst walls were composed only of Brenner tumor (50% in area) and struma ovarii (50% in area). Hemorrhage and ischemic changes were seen. Other elements were not recognized. No malignant transformation was noted. These two elements were separately present, and no mergers between them were recognized. Immunohistochemically, the Brenner tumor element was positive for cytokeratins (AE1/3 and CAM5.2) and Ki67 (labeling=3%), but negative for thyroglobulin, TTF-1, p53, CA125, and vimentin. The struma ovarii element was positive for cytokeratins (AE1/3 and CAM5.2), thyroglobulin, TTF-1 and Ki67 (labeling=5%), but negative for p53, CA125 and vimentin. The findings suggests that there were cases of ovarian cyst composed only of Brenner tumor and struma ovarii, that such a case may be monodermal mature cystic teratoma or the Brenner tumor element was derived from surface epithelium in the preexisting struma ovarii, and that such a tumor manifest as cystic torsion.     

Ovarian strumal carcinoid--report of a case that matastasized

Ovarian teratomas are known for their ability to form a wide variety of tissues. One unusual example of this potential is the strumal carcinoid in which the thyroid tissue is found in intimate association with carcinoid tumor. Although considered as a malignant transformation of struma ovarii, it is almost always benign. We report a rare case of strumal carcionid in a 44 year old lady who had metastasis in the contralateral ovary, myometrium and lungs.     

RET oncogene activation in papillary thyroid carcinoma.

The RET proto-oncogene encodes a cell membrane tyrosine-kinase receptor protein whose ligands belong to the glial cell line-derived neurotrophic factor. RET functions as a multicompetent receptor complex that includes alphaGFRs and RET. Somatic rearrangements of RET designated as RET/PTC (from papillary thyroid carcinoma) were identified in papillary thyroid carcinoma before RET was recognized as the susceptibility gene for MEN2. There are now at least at least 15 types of RET/PTC rearrangements involving RET and 10 different genes. RET/PTC1 and RET/PTC3 are by far the most common rearrangements. All of the rearrangements are due to DNA damage and result in the fusion of the RET tyrosine-kinase (RET-TK) domain to the 5'-terminal region of heterologous genes. RET/PTC rearrangements are very common in radiation-induced tumors but have been detected in variable proportions of sporadic (i.e., non-radiation associated) papillary carcinomas. It is estimated that up to approximately half the papillary thyroid carcinomas in the United States and Canada harbor RET/PTC rearrangements, most commonly RET/PTC-1, followed by RET/PTC-3 and occasionally RET/PTC-2. The cause of these rearrangements in sporadic papillary carcinomas is not known, but the close association between their presence and the papillary carcinoma phenotype indicates that they play a causative role in tumor development. The proposed mechanisms of RET/PTC-induced tumorigenesis and the clinical and pathologic implications of RET/PTC activation are discussed.     

Imprint cytology of strumal carcinoid of the ovary: A case report with immunocytochemical analysis

Strumal carcinoid is a rare ovarian tumor defined as carcinoid associated with struma ovarii. We report here the second cytological case of strumal carcinoid and performed immunocytochemical analysis for the first time. A 68‐year‐old Japanese female was found to have a solid tumor with small cystic components in the left ovary, and bilateral salpingo‐oophorectomy was performed. The Papanicolaou smear of the imprint cytological specimen of the left ovarian tumor revealed presence of two distinct components. The first component included thyroid follicles, which was composed of flat sheets of polygonal epithelial cells without nuclear groove and intranuclear inclusion. The other component was composed of trabecular clusters of columnar cells containing round to slender nuclei with “salt and pepper” chromatin. Immunocytochemical analysis revealed that synaptophysin was expressed in the latter component. Therefore, a cytodiagnosis of strumal carcinoid was made. Histopathological analyses confirmed the diagnosis of strumal carcinoid. Albeit rare, carcinoid tumor occurs in the ovary, and the recognition of characteristic nuclear features and cellular arrangement leads to correct cytodiagnosis. Presence of struma ovarii component suggests an ovarian origin. Moreover, immunocytochemical analysis for neuroendocrine markers aids its differential diagnosis from granulosa cell tumor and carcinoma arising from struma ovarii.