The largest reported papillary thyroid carcinoma arising in struma ovarii and metastasis to opposite ovary: case report and review of literature

Abstract

BackgroundMalignant struma ovarii (MSO) is a very rare, germ cell tumor of the ovary, histologically identical to differentiated thyroid cancers. Struma ovarii (SO) is difficult to diagnose on clinical basis or imaging and is mostly discovered incidentally, with few published cases in the literature.Case presentationA 42-year old primiparous woman presented with abdominal pain and midline pelvic palpable firm mass arising from the pelvis. Imaging showed pelvic solid cystic mass. Total abdominal hysterectomy, bilateral salpingo-oopherectomy (TAH BSO) and infracolic omentectomy were performed. Histopathology revealed left ovary papillary thyroid carcinoma (PTC) arising in SO (11 cm) and metastatic papillary thyroid carcinoma in the right ovary. Thyroid functions tests were all normal, ultrasound thyroid showed two complex nodules in the left thyroid lobe. Total thyroidectomy was decided, but the patient refused further surgical management and was lost to follow up as she left the country. We undertook a comprehensive literature search, and MSO and thyroid management data from 23 additional publications were analyzed and tabulated. This PTC MSO is probably the largest reported in the literature.ConclusionsAmong the different surgeries for MSO, TAH + BSO appears to have the best clinical outcome. However, unilateral salpingo-oopherectomy/ unilateral oophorectomy and bilateral salpingo-oopherectomy also seem effective. Ovarian cystectomy alone seems associated with higher recurrence. There remains no consensus on the associations between MSO tumor size and potential extent of metastasis, and about the management of thyroid gland. However, surveillance and thyroid gland work up to detect concurrent thyroid cancer are recommended.

Papillary Thyroid Cancer in a Struma Ovarii in a 17-Year-Old Nulliparous Patient: A Case Report

“…Struma ovarii can occur in women of all ages, but it is most common in women in the fourth to sixth decades of life [3,6,7]. Although tumors are usually benign, <5% of all struma ovarii undergo neoplastic transformation, and the underlying mechanism remains unclear [8][9][10]. Similar to cancers of the thyroid gland, the most malignant type of struma ovarii is well differentiated thyroid cancer, and the most common is the papillary type (70%), whereas the follicular type (30%) is less common [2,7].…”

“…Malignant struma ovarii metastasis occurs in 5-23% of cases and spreads via lymphatic and blood pathways. It mainly occurs in the abdominal cavity, although blood-borne metastasis can occur in the liver, lungs, brain, bones, and the opposite ovary [10,14,15]. The tumor is often accidentally diagnosed during an abdominal/pelvic ultrasound/computed tomography (CT) scan or during surgery for other reasons [11][12][13].…”

Papillary Thyroid Carcinoma in Struma Ovarii

“…It is uncommon for a patient with struma ovarii to present with hyperthyroidism features. There is a small chance of the presence of a tumor in the peritoneum [6].…”

An unusual case of struma ovarii

“…Traditionally, struma ovarii does not secrete thyroid hormones, however, in 8% of cases clinical and biochemical features of hyperthyroidism have been described ( 4 ). Around 40% of cases are asymptomatic and are accidentally discovered by routine ultrasound ( 5 ). In symptomatic cases of struma ovarii, common symptoms include palpable abdominal mass, abdominal pain or vaginal bleeding as well as tachycardia and ascites ( 5 ).…”

“…Around 40% of cases are asymptomatic and are accidentally discovered by routine ultrasound ( 5 ). In symptomatic cases of struma ovarii, common symptoms include palpable abdominal mass, abdominal pain or vaginal bleeding as well as tachycardia and ascites ( 5 ). Biochemical features of patients with struma ovarii and hyperthyroidism are similar to those of patients with hyperthyroidism of the orthotopic thyroid gland, showing low thyroid-stimulating hormone (TSH) and elevated peripheral thyroid hormones.…”