Background: Struma ovarii is a variant of mature cystic teratoma or monodermal teratoma predominantly composed of mature thyroid tissue. Struma ovarii accounts for approximately 5 percent of all ovarian teratomas. The majority are benign tumours; however, malignant tumours of this type is found in a small percentage of cases. It is most common between the ages of 40 and 60 years .
Case details: 28 year old Female, presented with complaints of lower Abdominal pain – 6 months. Her menstrual cycles were regular with the normal flow with no dysmenorrhea. On bimanual pelvic examination, a mobile mass of 8 cm × 7 cm was found. Rest of the systemic examination was normal. Ultrasonography shows complex Right Ovarian Cyst. CA – 125 was normal. Patient underwent Laparotomy, Right Ovariatomy &Right Salphingectomy.Histology reported as Struma ovarii.
Conclusion: Struma ovarii is a rare tumor of the ovaries and its clinical appearance may vary: it may be asymptomatic, mimic malignant ovarian tumor, or present with symptoms of hyperthyroidism and, in rare cases, it can even be a malignant tumor. We present this case of benign struma ovarii for its rarity .