Endocrine Abstracts

Introduction: Although the most common cause of thyrotoxicosis is Graves’ disease, identification of other causes is important to establish appropriate management. The diagnosis of factitious thyrotoxicosis often presents a difficult challengebut should not be overlooked. We report a case of a patient with treated thyroid carcinoma who presented with factitious hyperthyroidism.

Observation: 50-year-old patient, followed for papillary thyroid microcarcinoma under L-Thyroxin 125µg, halted for 3 months, admitted for hyperthyroidism. The patient was then put on Carbimazol 90 mg/day + corticotherapy for 1 month. As the hyperthyroidism persisted and did not improve, he was given radioactive iodine therapy at a rate of 100mCi. All this evolved in a context of weight loss of 24 kg in 4 months. The clinical examination found a patient in general good condition, BMI: 17 kg/m², Burch Wartofsky score at 10, free thyroid compartment, no gynecomastia, testicles in place, not swollen, normal size. On biological test T4L: 3051 pmol/l vs 50 pmol/l (8.5-34.90), T3L: 30.43 ng/l vs 6.22 pg/ml (2-4.40), TSHus:0.05 µIU/ml, Tgus: 0.1 ng/ml, BHCG:< 5IU/l (< 5), CEA: 0.99 ng/ml (< 4.30), AFP:5.5 ng/ml (<8.8), LDH: 144 IU/l (125-220), cervical-thoracic-abdominal-pelvic CT scan objectified an anterosuperior mediastinal mass of thymic appearance with adenolymphitis of the ileo-coecal region, F-FDG PET-CT did not show a hypermetabolic processes at the thyroidectomy lodge, locoregional lymph node, or distant suspicious processes for dedifferentiated recurrence of papillary microcarcinoma. The diagnosis of factitious thyrotoxicosis was retained in view of the degression of thyroid hormones during his hospitalization with clinical improvement of the patient during the hospitalization: degression of symptoms, and weight gain of 3 kg. The diagnosis was confirmed after a psychiatric evaluation.

Conclusion: Thyrotoxicosis has a wide spectrum of etiologies. Patients with factitious thyrotoxicosis are extremely difficult to identify because they do not appear to be different from patients with thyrotoxicosis of other causes.