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Struma ovarii associated with hyperthyroidism, elevated CA 125 and pseudo‐Meigs syndrome may mimic advanced ovarian cancer

2008; Wiley; Volume: 32; Issue: 2 Linguagem: Inglês

10.1002/uog.5399

1469-0705

D. Paladini, M. Vassallo, G. Sglavo, Carmine Nappi,

Intraperitoneal and Appendiceal Malignancies

A 42-year-old woman was referred to our unit because of ascites, fever, diarrhea, vomiting and significant weight loss. During the year preceding her admission she had undergone total thyroidectomy for Basedow syndrome that was unresponsive to medical treatment, and was treated with tapazole because of the persistent symptoms of hyperthyroidism. At that time, a total body 131I scan had revealed intense tracer activity in the neck area and this finding was considered to be the cause of her thyrotoxicosis. The patient then discontinued the therapy owing to the significant side effects and, following the onset of profuse diarrhea and significant dehydration and weight loss, she was admitted to the gastroenterology unit of our hospital, where an ultrasound scan confirmed the presence of gross ascites and revealed the existence of a large mass in the right adnexal region. The patient was thus referred to our department. On transvaginal ultrasound examination, the presence of a large (11 × 7.3 × 8.0-cm), solid and moderately hyperechogenic mass, originating in the right ovary, was confirmed (Figure 1a). Its surface was irregular and there were weak acoustic stripes in the lower part of the mass, but without frank evidence of complete shadowing. The mass showed a characteristic pearl-like echogenicity. Power and pulsed-wave Doppler imaging revealed moderately high blood flow (Figure 2). Frank ascites was present. The serum CA 125 level was 2548 U/mL. Although the ultrasound appearance of the mass was not typical for epithelial ovarian cancer, the association of clinical findings was highly suggestive of malignancy and led to the decision to perform surgery. At laparotomy, 8 L of fluid was drained from the abdominal cavity and a sample sent for cytology. The large mass originating from the right ovary was excised and intraoperative pathological examination was performed, revealing a mature teratoma with high prevalence of thyroid tissue (struma ovarii) (Figure 1b). Intraoperative examination of all abdominal and pelvic organs did not reveal any additional lesion. Cytology was negative for malignant cells and the final pathology report confirmed the diagnosis of benign mature teratoma with a 95% struma ovarii component. Six weeks after surgery, serum CA 125 levels and thyroid function tests had completely normalized, and the patient is now disease free and receiving thyroid replacement therapy with levothyroxine. (a) Transvaginal ultrasound image demonstrating a large (11 × 7.3 × 8.0-cm), solid, hyperechogenic mass, originating in the right ovary. Note the irregular surface, as outlined by the fluid in the pelvis (arrows). There were also weak acoustic stripes in the lower part of the mass, but without frank evidence of complete shadowing. Note also the pearl-like hue of gray, characteristic of most of the mass. (b) The specimen after surgery. Note the whitish capsule, the irregular surface and the purplish aspect of the inner component. Doppler examination of the mass revealed moderately high blood flow (not evident here due to the high pulse repetition frequency needed to sample the vessel with the highest peak velocity of 25 cm/s) and low resistance and pulsatility indices. Note the ample diastolic flow component. Struma ovarii accounts for only 2.7% of germ cell tumors of the ovary and represents a rare form of mature ovarian teratoma composed entirely or predominantly of thyroid tissue1. It is generally a benign lesion, although a malignant form has been described in 5–37% of reported cases2. Most cases are asymptomatic and, despite the fact that these tumors contain a large amount of thyroid tissue, only 5% of them present signs of hyperthyroidism1. Ascites has been reported in 15–20% of all cases3, and in a few of these hydrothorax was also present, leading to pseudo-Meigs syndrome4-8. The association of struma ovarii with high titers of CA 125 is also rare, with only a few cases described recently in the literature7-9. The fact that struma ovarii may actually mimic an ovarian carcinoma, considering the clinical features of a prevalently solid ovarian mass and high titers of CA 125, has already been reported8, 9. In particular, as far as ultrasound imaging is concerned, the large size of the mass, its prevalently solid echostructure, the irregular walls and the low-resistance blood flow are all features seen more frequently in malignant than in benign ovarian lesions10; this has led to the inclusion of struma ovarii in a group of ovarian masses that are considered difficult to characterize on ultrasound examination, even when carried out by an expert10. In the index case, the other two clinical features, significant weight loss and diarrhea, increased even further the likelihood of an advanced ovarian cancer being present, with the latter possibly being considered as a paraneoplastic symptom. In conclusion, we confirm that struma ovarii is difficult to characterize on ultrasound examination and that it should be considered in the differential diagnosis of ovarian epithelial cancer whenever a solid, typically hyperechogenic mass is found on transvaginal ultrasound imaging in the presence of frank ascites, elevated CA 125 level and weight loss. D. Paladini*, M. Vassallo*, G. Sglavo*, C. Nappi*, * Fetal Cardiology Unit, Department of Obstetrics and Gynecology, University Federico II of Naples, Naples, Italy