Struma ovarii: A case report

Struma Ovarii (SO) is a rare form of teratoma of ovary containing predominantly thyroid tissue, usually comprising more than 50% of the overall mass. It accounts for 1% of all ovarian tumours in adults. Due to its rare presentation in paediatric age group, the exact incidence is not known.The association of SO with hyperthyroidism has been noted in approximately 8% of cases. Radiological evaluation helps in preliminary diagnosis of a complex ovarian cyst, however, a definitive diagnosis of SO can only be made upon extensive histopathological evaluation. Present report is of SO in a 12-year-old female patient, who initially presented with pain abdomen, vomiting and hyperthyroidism with mildly elevated thyroid hormones Triiodothyronine (T3) and Tetraiodothyronine (T4). Magnetic Resonance Imaging (MRI) whole abdomen showed evidence of right-sided dermoid with mild ascites. An exploratory laparotomy was done followed by right ovarian cystectomy and histopathology revealed a mature teratoma predominantly comprising of thyroid tissue (>90% of total ovarian mass), thereby confirming the diagnosis of SO. After one month of surgical resection, the patient’s thyroid profile showed decrease in fT3 and fT4 levels. The index case highlights the unusual occurrence of SO in a paediatric patient along with the role of an extensive histopathological evaluation in diagnosis of the same.

Plasma carcinoembryonic antigen (CEA) levels were studied in all available members of 17 families in which a presumed sporadic retinoblastoma had occurred. In 9 of the 17 families, close relatives of the patient had elevated CEA levels in the absence of demonstrable disease; this we have termed the "CEA family syndrome." In two families (Nos. 8 and 17) one or both parents and all of the siblings had elevated CEA levels. To our knowledge, this is the first report of abnormal CEA levels in unaffected family members of patients with nonadenocarcinoma-type malignancies. As follow-up studies of such families become available, detection of the "CEA family syndrome" may prove to be a useful means of locating individuals with inherited premalignant or malignant conditions and may provide a stimulus for additional clinical examination of asymptomatic individuals considered at risk for developing malignancies.

Background: Struma ovarii is a rare monodermal variant of ovarian teratoma, characterized by the presence of mature thyroid tissue comprising more than 50% of the Tumor. Struma ovarii is a rare ovarian tumor, accounting for 1% of all ovarian tumors and 2-5% of ovarian teratomas. It consists predominantly or entirely of thyroid tissue and can occasionally exhibit functional thyroid activity. Case Presentation: This case report discusses a 41-year-old female who presented with nonspecific abdominal discom- fort and a gradually enlarging pelvic mass. Pelvic ultrasonography revealed a complex, predominantly cystic ovarian mass. The patient underwent a laparoscopic salpingo-oophorectomy, and histopathological examination confirmed the diagnosis of struma ovarii. Thyroid function tests were within normal limits, and no evidence of malignancy or metastatic disease was observed. The patient’s postoperative course was uneventful, with complete resolution of symptoms. Struma ovarii can present diagnostic challenges due to its nonspecific clinical and radiological features, often mimicking other ovarian neoplasms. Although typically benign, it can occasionally undergo malignant transformation or cause thyrotoxi- cosis. This case emphasizes the importance of considering struma ovarii in the differential diagnosis of ovarian masses and highlights the role of histopathology in definitive diagnosis. Early recognition and appropriate surgical management are crucial for favorable outcomes in patients with this rare ovarian tumor. Conclusion: Struma ovarii is often asymptomatic or presents with nonspecific symptoms, making preoperative diagnosis challenging. Surgical excision remains the mainstay of treatment, with a favorable prognosis in most benign cases. CME J 2025; 4(1); 64-67

Struma ovarii is a rare ovarian teratoma composed predominantly of thyroid tissue, representing less than 1% of all ovarian tumors. The clinical presentation of struma ovarii can vary widely, from an asymptomatic palpable abdominal mass, hyperthyroidism (elevated free T4 and/or T3; low TSH), and, in rare cases, pseudo-Meigs syndrome. Diagnosis is often based on postoperative histopathological confirmation of thyroid tissue. We present a case of a 44-year-old Hispanic female with an incidental finding of an adnexal mass, pleural effusion, and ascitic fluid, but with normal tumor markers, cancer antigen 125 (CA-125), and carcinoembryonic antigen (CEA). Postoperative pathological examination confirmed struma ovarii, with pseudo-Meigs syndrome. Unexpectedly, the patient developed ovarian remnant syndrome (ORS). This case contributes to the limited literature describing struma ovarii associated with pseudo-Meigs syndrome and normal tumor markers, highlighting the diverse clinical spectrum of this tumor. It also underscores the need for a high index of suspicion for struma ovarii in atypical cases, regardless of tumor marker levels. The development of ORS further emphasizes the importance of long-term follow-up after definitive surgical management.

Struma ovarii is an ovarian tumor, characterized by the presence of thyroid tissue comprising >50% of the overall mass. Although struma ovarii does not usually secrete thyroid hormones, there are cases in which it produces thyroid hormones, which results in hyperthyroidism. Here, we report the case of a 73-year-old female who presented with a right ovarian mass and symptoms suggestive of thyrotoxicosis. Her thyroid function test showed suppressed thyroid-stimulating hormone and elevated T3 and T4 levels. We suspected thyroiditis initially. Later, in view of persistent thyrotoxicosis, she was started on antithyroid drugs. Tc99 pertechnetate thyroid uptake scan showed absent uptake in the neck. A possibility of struma ovarii was considered. She underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy. Histopathology revealed >80% thyroid tissue suggestive of struma ovarii with a coexistent Brenner tumor. Postoperatively, her thyrotoxicosis got resolved. To conclude, in any case of thyrotoxicosis that is persisting and with absent uptake in the neck, rare cases such as struma ovarii should be considered. Struma ovarii with a coexistent Brenner tumor is a very rare finding.

Leukocyte alkaline phosphatase (LAP) scores in peripheral blood and plasma carcinoembryonic antigen (CEA) levels were determined in 58 lung cancer patients and compared with those of 22 healthy persons, who served as controls. In the control group we found LAP scores of 54 +/- 28 and CEA levels of 4 +/- 3 ng/ml. The 97.7% confidence intervals are: LAP score < 110 and CEA level < 10. In the patients with limited lung cancer we found LAP scores of 152.4 +/- 36.7 and CEA levels of 22.7 +/- 48 ng/ml. The 97.7% confidence intervals are: LAP score > 78.6 and CEA level > 0. In the patients with extensive lung cancer we found LAP scores of 272 +/- 49 and CEA levels of 47.5 +/- 80.4 ng/ml. The 97.7% confidence intervals are: LAP score > 174 and CEA level > 0. The sensitivity of each marker is discussed, here as percent of false-negative results, denoted PFN, and meaning that with a chosen threshold for the marker level, only PFN% of the patients with a given condition (e.g. extensive lung cancer) might have a marker level less than the chosen threshold and could therefore be assumed healthy. The sensitivity of the LAP score is 0.05% PFN for the group of patients with extensive lung cancer, and we conclude that indeed LAP score < 110 indicates a very low probability of having extensive malignancy. The sensitivity of the CEA level is 32% PFN. The sensitivity of the LAP score to limited lung cancer is 12% PFN for the group of patients with that condition compared with 40% of CEA. The specificities of both LAP score and CEA levels, expressed as percent of false-positive results in the control group, are fair (2.3%), provided that the common conditions, other than cancer, that elevate LAP score and/or CEA levels are well known and can be eliminated by the physician. It is concluded that the LAP score is considerably more useful than the CEA level as a marker for extensive lung cancer.

Struma ovarii is a rare monodermal ovarian teratoma composed predominantly of thyroid tissue, accounting for approximately 1% of ovarian neoplasms and 2%-3% of mature teratomas. Its coexistence with differentiated thyroid carcinoma - and particularly in the setting of normocalcemic primary hyperparathyroidism - has not been previously described. A 26-year-old woman presented with a painless 2×2 cm midline neck swelling. Ultrasound and fine-needle aspiration confirmed papillary thyroid carcinoma. Biochemistry revealed an elevated parathyroid hormone (81.1pg/mL) despite normal serum calcium (9.4 mg/dL) and vitamin D insufficiency. Tc-99m sestamibi single-photon emission tomography with computed tomography (SPECT-CT) localized a left inferior parathyroid adenoma. She underwent total thyroidectomy, central lymph node dissection, and parathyroidectomy. Forty-five days later, whole-body I-131 scintigraphy for remnant ablation revealed unexpected pelvic uptake. SPECT-CT and transvaginal ultrasound identified a 2.6×2.5 cm left ovarian cystic mass. Tumor markers were normal. Laparoscopic cystectomy was performed. Histopathology confirmed benign struma ovarii arising within a mature cystic teratoma. The patient's postoperative course was uneventful, she resumed thyroid hormone replacement, and follow-up showed normalization of parathyroid hormone levels without recurrence. Concurrent presentation of papillary thyroid carcinoma, normocalcemic primary hyperparathyroidism, and struma ovarii constitutes a novel endocrine triad not previously described. Normocalcemic primary hyperparathyroidism requires a high index of suspicion and rigorous biochemical and imaging evaluation, since normal serum calcium may mask a significant parathyroid adenoma. Pelvic radioiodine uptake outside the thyroid bed can also be seen in benign struma ovarii, not only metastasis, underscoring the need to correlate functional and anatomical imaging. Accurate diagnosis and tailored management of such complex endocrine neoplasms depend on a multidisciplinary approach and strict long‑term surveillance. This report provides important educational insights for endocrinologists and surgeons managing concurrent endocrine pathologies. Normocalcemic primary hyperparathyroidism may mask a significant parathyroid adenoma and requires high clinical suspicion despite normal serum calcium. Critically, in thyroid cancer surveillance, unexpected extra-thyroidal radioiodine uptake - particularly in the pelvis - must include struma ovarii in the differential diagnosis to prevent inappropriate treatment escalation. Multimodal imaging and thorough histopathological evaluation are essential to distinguish benign struma ovarii from metastatic disease and guide appropriate management.

Thyroid tissue is a relatively frequent component of mature teratoma and can occur in 5-20 % of cases. Struma ovarii is defined as ovarian goiter which comprises either entirely or predominantly thyroid tissue (>50 %). This also includes cases of mature teratoma with less than 50 % thyroid tissue but harboring thyroid-associated malignancy. A total of 118 patients with mature teratoma containing thyroid tissue were identified at our institution (1989 to 2014). Ninety-six cases were diagnosed struma ovarii, including 10 cases of papillary thyroid carcinoma, 1 case of highly differentiated follicular carcinoma of ovarian origin (HDFCO), 5 cases of strumal carcinoid, and 80 cases of struma ovarii (53 cases of thyroid-only struma ovarii). Six cases had diffuse adenomatous hyperplasia, and seven cases had focal adenomatous hyperplasia. There was no recurrence on follow-up except one of the papillary thyroid carcinomas. Concurrent primary ovarian lesions included: serous cystadenoma--3, mucinous cystadenoma--4, Brenner tumor--3, thecoma--2, ovarian fibroma--1, and focal hilus cell hyperplasia--4 cases. In this series, papillary thyroid carcinoma and strumal carcinoid were the most common well-differentiated neoplasm/malignancies arising in struma ovarii; these demonstrate a minimal or no aggressive clinical behavior.

P2.01-40 Normalization of Carcinoembryonic Antigen Levels Is Associated with Survival Improvement in Patients with Advanced Non-Small Cell Lung Cancer

IntroductionStruma ovarii is a subtype of mature teratoma characterized by the presence of predominantly thyroid tissue (>50%) [1]. This condition is usually benign, with malignant transformation occurring in only 0.5-5% of cases, requiring management similar to that of thyroid cancer. The most common malignancy found in struma ovarii, similar to the thyroid gland, is papillary thyroid carcinoma (PTC) [2]. Here, we report a case of a 73-year-old woman with papillary thyroid cancer in struma ovarii.Clinical CaseA 73-year-old female patient, who was admitted with abdominal pain, underwent bilateral salpingo-oophorectomy due to 4 and 5 cm lesions thought to be hemorrhagic cysts on her right and left ovaries. Pathology result revealed a 2.2 cm teratoma in the left ovary. In the sections, in addition to struma ovarii (>90%), areas of mature teratoma differentiated in the direction of the ectoderm were observed. Two papillary carcinoma foci of 1 cm and 0.5 cm in diameter were detected within the struma ovarii, but no lymphovascular invasion or capsular involvement was observed (Picture 1). In the right ovary, only areas of mature teratoma (struma ovarii) consisting of benign thyroid tissue were seen. Her comorbidities included Type 2 Diabetes Mellitus, Stage 3 Chronic Kidney Disease and Hepatitis B virus carriage. Thyroid ultrasonography result showed normal thyroid gland size and heterogeneous parenchyma with decreased echogenicity. PET/CT scan showed no pathological FDG uptake in the body in favor of malignancy. Laboratory results were given in Table 1. The patient was evaluated by the thyroid council; the stage was calculated as T1a(m)N0M0, AGES and MACIS scores were considered as low risk and a follow-up decision was made for the patient. Routine thyroid and neck ultrasonography along with abdominal and lung imaging were recommended. TSH level was planned to be maintained between 0.5-1 uU/mL and annual thyroglobulin follow-up was planned.ConclusionThe primary treatment for malignant struma ovarii is the surgical removal of the tumor. Additional therapies, such as thyroidectomy and radioiodine, may be required depending on the presence of metastatic disease and the risk of recurrence [2]. In cases with a low risk of recurrence, as in our patient (no extraovarian extension or distant metastases), most authors recommend levothyroxine to suppress TSH to the lower limit or slightly below normal, along with annual serum thyroglobulin monitoring. Severe elevations in thyroglobulin may indicate recurrence or metastatic disease. Long-term monitoring (at least 10 years) of serum thyroglobulin is necessary for patients with malignant struma ovarii. If the biochemical evidence of persistent or recurrent disease is found, appropriate imaging, including the pelvis, should be performed [3].Financial disclosures: NoneFunding resources: NoneFigure 1:Histological and radiological findings of the patient Table 1:Laboratory results

Struma ovarii is a very rare histological entity among ovarian tumors. We report the case of a 35-year-old woman presenting with pelvic pain associated with dysmenorrhea. Radiologic examination revealed a left ovarian mass with no signs of metastasis. The patient underwent surgical treatment, which confirmed the presence of thyroid tissue in the left ovary, suggestive of invasive follicular carcinoma. The aim of this case is to highlight this exceptional histological type, which first requires an appropriate diagnostic strategy to rule out metastatic involvement from a primary thyroid tumor before confirming the diagnosis of struma ovarii.

7181 Background: Elevated preoperative serum carcinoembryonic antigen (CEA) level has been reported to be a poor prognostic factor in non-small cell lung cancer (NSCLC). Surgical indication remains controversial in clinical (c-) stage I NSCLC patients with very high CEA levels. Methods: Between Jan. 1985 and Dec. 2000, 1502 patients with c-stage I NSCLC underwent surgical resection at the National Cancer Center Hospital, Tokyo, Japan. They were retrospectively analyzed for preoerative CEA level, pathologic (p-) stage and postoperative prognosis. Patients were divided into three groups according to CEA levels: Group A (n=1077, CEA< 5.0ng/ml), Group B (n=394, 5.0 ≤ CEA < 50ng/ml), and Group C (n=31, 50ng/ml ≤ CEA). Results: The p-stages of the 1502 patients were: stage I in 909 patients (60.5%), stage II in 464 (30.9%), stage III in 52 (3.5%) and stage IV in 64(4.3%). Group C patients were significantly (P < 0.0001) upstaged post-operatively; among the 31 patients in Group C, 4 (12.9%) had p-stage II disease, 12 (38.7%) stage III, and 4 (12.9%) stage IV. Among the 1077/394 patients in Group A/B, 259 (24.0%) /175 (44.4%) were upstage to p-stage II or more, respectively. The 5-year survival was 81.8% in Group A (n=1077), 63.5% in Group B (n=394) and 28.2% in Group C (P < 0.0001). There were 7 long-term survivors (> 5 years) in Group C. Conclusions: Patients with high CEA levels (50ng/ml ≤) significantly had advanced disease in terms of p-stage. High CEA level was a poor prognostic factor. However, we did observe long term survivors in this group, and high CEA per se is not a contraindication for surgical resection after intensive preoperative evaluation. No significant financial relationships to disclose.

Malignant struma ovarii in an 11-year-old girl

Disclosure: C.A. Onuegbu: None. R. Lopez Fanas: None. M. Aziz: None. N. Suda: None. Background: Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome characterized by solid tumors secreting incompletely processed insulin-like growth factor-2 (IGF-2), exerting insulin-like effects. We report a rare case of malignant struma ovarii as the probable source of excess IGF-2, resulting in recurrent hypoglycemia. Case Presentation: A 68-year-old woman presented with abdominal discomfort, 60-pound unintentional weight loss and early satiety for a year. Imaging revealed a 9.8 cm right adnexal mass and a known benign pancreatic head intraductal papillary mucinous neoplasm. During her hospitalization, she experienced recurrent symptomatic fasting hypoglycemia, with serum glucose nadir of 59 mg/dL with symptoms of fatigue, lightheadedness, and dizziness consistent with level 2 hypoglycemia. Her symptoms resolved after administration of intravenous (IV) dextrose. She had a prior admission with stroke-like symptoms and a serum glucose of 51 mg/dL, with resolution of symptoms after IV dextrose. She had no history of bariatric surgery and was not taking hypoglycemic agents. Laboratory tests revealed: glucose 63 mg/dL, insulin &amp;lt;3 μIU/mL, C-peptide 1.49 ng/mL (0.81-3.85), HbA1c 4.2%, random cortisol 19.3 μg/dL (4-20), albumin 1.9 g/dL (3.5-5), TSH 1.05 μU/mL (0.3-4.2), IGF-2 320 ng/mL (267-616), IGF-1 16 ng/mL (34-194), IGF-2:IGF-1 ratio of 20, IGF-binding protein-2 (IGFBP-2) 333 ng/mL (47-350). Liver and kidney function were normal. She underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. The pathology revealed malignant struma ovarii with stromal carcinoid component demonstrating thyroid and neuroendocrine features. Immunohistochemistry was positive for neuroendocrine markers chromogranin and synaptophysin, and calretinin (a marker for mesothelioma). Postoperatively, her blood glucose levels normalized, ranging from 77-126 mg/dL. Unfortunately, she died from septic shock secondary to aspiration pneumonia. Discussion: NICTH presents with fasting hypoglycemia and suppressed insulin levels, typically due to tumor overproduction of IGF-2. IGF-2 increases glucose uptake via insulin receptor activation and impairs counter-regulatory hormones glucagon and growth hormone. Diagnosis can be made despite normal IGF-2 levels, as normal IGFBP-2 with hypoalbuminemia suggests elevated free IGF-2. Struma ovarii is a rare ovarian tumor containing thyroid tissue; the presence of carcinoid features is even rarer and may confer more aggressive behavior. To our knowledge, struma ovarii has not been previously reported as a source of IGF-2. Although IGF-2 staining was unavailable, resolution of hypoglycemia post-resection, and an IGF ratio of 20 implicates the tumor as the source. Surgery is curative, though corticosteroids, growth hormone, or somatostatin analogues are utilized when surgery is not feasible. Presentation: Saturday, July 12, 2025

To describe the sonographic features typical of struma ovarii. Twenty-five women diagnosed as having a struma ovarii at histopathological examination were recruited from databases available in the participating hospitals (Bologna, Rome, Leuven, Malmö) in the period between May 1997 to March 2006. Thirteen patients had pure struma ovarii, while in 12 cases an adjacent dermoid was found comprising less than 50% of the mass. Preoperative transabdominal and transvaginal sonographic findings were obtained, together with clinical/surgical reports. The diameters of the masses were measured, and morphology, content, presence of septa and solid portions were analyzed. Vascularization of the masses was evaluated in a semiquantitative manner. Subjective assessment after sonographic examination was recorded and compared to the final histological diagnosis. At surgery, 23/25 patients (92%) had a unilateral adnexal mass; two cases were bilateral. Mean diameter ranged from 25 to 214 mm (median, 60 mm). Sonographically, struma ovarii were multilocular–solid in 14 (59%) cases, multilocular in six (22%), unilocular–solid in three (11%) and purely unilocular or purely solid in one case each. Cystic content was anechoic in 11 (41%), ‘ground-glass’ in three (11%) and mixed in four (15%), while low-level echoes were present in eight (30%) cases. Color or power Doppler found no vascularization of the mass in five (19%) patients, minimal in six (22%), moderate in 14 (52%) and strong in two (7%). Subjective assessment of the risk of malignancy was correct in 19/27 cases (70%), but in no patient was struma ovarii suspected at transvaginal sonography. Low-level or anechoic multilocular and multilocular–solid tumors can indicate the possibility of a struma ovarii, especially when found with a minor part resembling a typical dermoid. Minimal/moderate vascularization of the mass should strengthen such diagnostic suspicion. Clinical symptoms are vague and unspecific, and so of no value in the diagnosis.