Struma ovarii is a rare tumor that is defined as an ovarian teratoma with a thyroid tissue component exceeding 50%. Most of these tumors are benign, with malignant struma ovarii occurring in <1% of patients. Here, we describe the case of a 49-year-old female patient with malignant struma ovarii who developed thoracic spine metastasis. She had undergone an oophorectomy and was diagnosed with struma ovarii 10 years previously. She had remained recurrence-free thereafter. At 49 years of age, she developed low back pain and was admitted to our hospital for evaluation of a spinal tumor at the Th7 level. An emergency bone biopsy led to a diagnosis of metastasis from malignant struma ovarii. External beam radiotherapy inhibited further tumor growth and there was no resulting muscle weakness. This is the first report of spinal metastasis occurring 10 years after resection of struma ovarii, indicating the need for long-term follow-up.
Biopsy ; Diagnosis ; Emergencies ; Female ; Humans ; Low Back Pain ; Middle Aged ; Muscle Weakness ; Neoplasm Metastasis* ; Ovariectomy ; Radiotherapy ; Recurrence ; Spinal Neoplasms ; Spine ; Struma Ovarii* ; Teratoma ; Thyroid Gland

The purpose of the present study was to examine the validity and reliability of the stages of change for sedentary behavior scale among workers. The participants were 2400 Japanese workers aged 20-59 years (male: 50.0%, mean age: 40.4±10.8 years) recruited from research company. With an internet-based survey, the stages of change for sedentary behavior, total sitting time (min/day), socio-demographic characteristics, health-related characteristics and work-related characteristics were obtained. “Too much sitting” was defined as sitting or lying down for a total of 8 hours or more per day on average. Participants were categorized into one of 5 stages based on their present status for “too much sitting” and motivational readiness for reducing sedentary behavior. For the criterion validity, a one-way analysis of variance was utilized to compare the total sitting time among the 5 stages. To assess the test-retest reliability, randomly-selected 200 workers answered the scale again two weeks later. Then, the Kappa index (k) was calculated. As results, the means of total sitting time were significantly distinguished across the stages [F (4, 2395) =111.5, p<0.001, η2=0.16]. Participants in early stages (precontemplation, contemplation, preparation) had significantly longer sitting time than those in the Maintenance (Precontemplation>Contemplation, Preparation>Action, Maintenance) (p<0.001). The scale to assess the readiness to reduce sedentary time has shown good 2-week test-retest reliability (k=0.64). These results suggest that the developed scale presented good validity and reliability to assess the motivational readiness for reducing prolonged sedentary behavior among Japanese workers.