Endocrine Abstracts

Introduction: Multiple myeloma (MM) is a lethal hematological malignancy with an incidence of 6.1/100 000 per year. The association of thyroid autoimmune diseases and MM is rare and has not been fully investigated. Also, it is well known that agranulocytosis is a potential lethal adverse reaction of antithyroid treatment.

Case report: We present the case of a 59-year-old female patient that presented with symptoms of hyperthyroidism. Objectively: Mild bilateral proptosis and a slightly enlarged thyroid gland. She had a partial left lobectomy in 2006 (euthyroid, before and after the intervention without any thyroid medication) and was diagnosed with MM and osteoporosis in 2016. Without significant family history. The laboratory tests revealed low TSH level, high (FT4, FT3 and TSH-R Antibodies) level. The thyroid ultrasound: Increased volume and vascularization. The Technetium 99 scintigraphy: Increased uptake throughout the thyroid. Her CBC test was normal (WBC were at the low level of the norm). The myelogram: Complete remission of MM. The diagnosis of hyperthyroidism due to Graves’ disease in a patient with MM was concluded. The patient started treatment with a low dose of methimazole but the first days, in the afternoon, she had temperature of 38°C. We repeated everyday CBC, which had no changes from the previous lab tests. She continued the methimazole and in the next few days, her temperature was within normal range and CBC was also normal. After 9 days of admission, the patient got discharged under treatment with low dose of methimazole. It was planned to be treated with radioactive iodine 131 as a definitive treatment, after she achieved euthyroidism. A week after discharge, the patient came back with severe sore throat, tiredness, and temperature of 39°C. Methimazole was discontinued immediately and the lab tests revealed agranulocytosis. After several days, her state improved with supportive therapy and got discharged from the hospital. Two weeks later she was treated with radioactive iodine 131, under treatment with Prednisone before and after taking iodine. Two months later, she was euthyroide and in a good general condition.

Conclusion: Based on available literature, patients with MM appear to be at increased risk for thyroid autoimmune conditions, our case, confirms that. By the other hand, maybe the condition of MM increases the risk of the agranulocitosis caused by antithyroid drugs. Every physician must be careful in using them, in patient with Graves’ disease and MM, even if it is in complete remission of multiple myeloma.