BRAF T1799A mutation occurring in a case of malignant struma ovarii

Struma ovarii is an extremely rare tumor that occasionally undergoes malignant transformation. Because struma ovarii is composed of thyroid tissue, it is conceivable that the pathogenetic events involved in thyroid follicular transformation may take place also in struma ovarii. The authors describe a case of a classical variant of papillary thyroid carcinoma arising in a struma ovarii of a 22-year-old female. The tumor was heterozygous for BRAF T1799A mutation. No ret/ PTC-1 or ret/PTC-3 rearrangements were detected. This finding would suggest that malignant struma ovarii is similar histologically and genetically to primary papillary thyroid carcinoma.     

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.     

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.     

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.     

Malignant Struma Ovarii: A Case Report

We present a case of a 40-yr-old woman diagnosed with a primary malignant struma ovarii. The patient was admitted with the complaint of pelvic pain and a large pelvic mass in the mid-portion of lower abdomen on gynecological examination. Pre-operative tumor markers and routine biochemistry were unremarkable. She was treated with total abdominal hysterectomy and right salpingo-oopherectomy. Post-operatively, she was diagnosed with a malignant struma ovarii through the usage of histopathological criteria similar to the guidelines for primary thyroid gland disease. The patient was subsequently performed left salpingo-oopherectomy and retroperitoneal pelvic lympadenectomy for re-staging. Although, left ovary and lymph nodes were histopathologically normal, she was offered thyroidectomy but she refused to accept the offer. Thyroglobulin level was monitored in the post-operative period. She is free of the disease for 18 months.     

Thyroid tissue outside the thyroid gland: Differential diagnosis and associated diagnostic challenges

The presence of thyroid tissue outside of the thyroid gland may occur in various clinical settings and anatomic locations and includes both benign and malignant differential diagnoses. Some of these entities include thyroglossal duct cyst, lingual thyroid, parasitic nodule, thyroid tissue within a lymph node and struma ovarii. In routine daily practice, these entities do pose diagnostic challenges for the pathologists. Differential diagnostic considerations depend largely on the location of lesion and the histologic features. A definitive diagnosis may remain unclear in some cases while knowledge is still evolving in others i.e., incidentally detected bland appearing thyroid follicles in a lateral neck lymph node. This article aims to elaborate on the various entities characterized by thyroid tissue outside of the thyroid gland, both benign and malignant, and the relevant differential diagnostic considerations.     

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.     

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.     

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.     

Simultaneous strumal ovarii and lymphoma with emphasis on the diagnostic usefulness of immunohistochemical stains.

Strumal ovarii has been rarely associated with other tumors, such as carcinoid tumor, carcinoma, and primary ovarian malignant lymphoma. We report the coexistence of a strumal ovarii and ovarian involvement by malignant lymphoma in a 70-year-old woman. The tumors were detected 10 years following exposure to ionizing radiation during the Chernobyl nuclear tragedy.     

Infertility: Metastatic ovarian strumosis in an in-vitro fertilization patient

Malignant struma ovarii is a very rare tumour, with considerablecontroversy concerning the necessary histologic features formalignancy. Still more infrequent is the condition termed ‘metastaticovarian strumosis’ or simply ‘benign strumosis orstrumatosis’ and characterized by the presence of peritonealimplants of mature thyroid tissue occurring in struma ovarii.‘Strumosis’ should not be confused with malignancy.Presented is a case of ‘metastatic ovarian strumosis’in a 36-year-old woman with primary infertility who underwentthree in-vitro fertilization (IVF) cycles with ovarian stimulation.She received hormonal treatment for 6 months after her lastIVF because of ‘persistent enlarged ovarian follicles’which were in fact ‘thyroid follicles’.     

Highly differentiated follicular carcinoma of ovary: Use of imprint cytology at intraoperative consultation

Highly differentiated follicular carcinoma of ovary (HDFCO) is a rare entity known to arise in struma ovarii. Clinical presentation and radiological features mimic other cystic ovarian neoplasm. Thus, intraoperative diagnosis of this entity can be challenging. We hereby report a HDFCO case of a 52‐year‐old woman, who presented with significant abdominal bloating for 3 months. Imaging showed a 11.7 cm left adnexal‐mixed cystic and solid mass, adhering to the bowel with ascites. The mass was examined intraoperatively and showed multilocular cysts filled with straw or red brown‐colored gelatinous fluid. Microscopically, the tumor consisted of small and large follicles with proteinous material and bland‐looking cuboidal cells, suspicious for struma ovarii or granulosa cell tumor with extensive cystic changes, while imprint cytology slides showed watery colloid with cracking artifact favoring the former. However, the adherence to the bowel suggested HDFCO, and prompted surgical staging. The histology of the ovarian mass in the permanent section resembled goiterous thyroid tissue with invasion of endocervical stroma, uterine wall and colonic serosa, and presence of tumor nodules in omentum leading to the diagnosis of HDFCO. Due to striking resemblance of HDFCO to benign thyroid goiter, searching for invasive and metastatic foci is crucial for correct diagnosis. In addition, intraoperative imprint cytology revealing colloid with cracking artifact is helpful for differentiating struma ovarii and/or HDFCO from other ovarian lesions.     

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.     

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.     

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.