Extensive peritoneal implant metastases of malignant struma ovarii treated by thyroidectomy and 131I therapy: A case report.

RATIONALE: Malignant struma ovarii is extremely rare in the clinic. The diagnosis and modalities of treatment are still controversial. Here we describe a case of extensive peritoneal implant metastasis originating from malignant struma ovarii discovered 14 years after ovariectomy and chemotherapy. PATIENT CONCERNS: A 48-year-old female was admitted to our clinic due to hematochezia with a past history of left malignant struma ovarii. Enhanced computed tomography (CT) examination suggested multiple metastasis nodules in the abdomen and pelvic cavity. DIAGNOSES: Laparoscopy biopsy results of intraperitoneal nodules showed a metastasis of papillary thyroid carcinoma. While pathological examination after total thyroidectomy showed no definite malignant tumor component in the thyroid tissue. Finally, combined with the patient's past history of malignant struma ovarii, peritoneal implantation metastasis derived from the malignant struma ovarii was diagnosed. INTERVENTIONS: The patient was treated by total thyroidectomy and iodine 131 (I) therapy. Post-therapy iodine scan and the single-photon emission computed tomography/computed tomography (SPECT/CT) fusion image showed iodine uptake in the distal descending colon, sigmoid colon, rectal lesions, and a larger lesion in the liver. OUTCOME: After treatment, although the thyroid globulin remained at a high level 3 months after treatment, the patient's hematochezia was relieved. LESSONS: Therefore, thyroidectomy followed by adjuvant I treatment should be recommended in patients with malignant struma ovarii as metastatic risk is difficult to predict based on histopathologic examination.

METASTATIC RADIOIODINE AVID STRUMA OVARII ASSOCIATED WITH PSEUDO-MEIGS' SYNDROME.

We report a case of 21 years old lady who presented with ascites, left adnexal mass and elevated CA-125. With suspicion of ovarian malignancy, she underwent left salpingo-oophorectomy with omental biopsy. Histopathology revealed: 'follicular variant of papillary thyroid carcinoma arising in struma ovarii' with metastatic papillary thyroid carcinoma in omental and peritoneal nodules. Patient underwent total thyroidectomy followed by radioactive iodine therapy for metastatic omental and peritoneal disease. Post-therapy whole body scan, revealed extensive I-131 avid disease metastatic disease involving the chest, abdomen, pelvis and the musculoskeletal system. Patient was treated with multiple doses of high dose radioactive iodine. She became symptom free on supra-physiologic doses of oral thyroxin however her high thyroglobulin levels and residual radioiodine avid metastatic disease required further treatment. In literature a few cases of struma ovarii have been reported with elevated CA-125 and associated pseudo-Meigs' syndrome. The treatment for this rare disease is still not standardized and poses a therapeutic challenge. Our case emphasizes the need for a multidisciplinary approach for managing struma ovarii.

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.