Endocrine Abstracts

Introduction: The Marine–Lenhart syndrome is a rare cause of hyperthyroidism that is associated with the simultaneous or sequential presence of characteristics related to Graves’ disease and toxic nodular or multinodular goiter. It’s validity as a disease is controversial and some authors believe that these are cases of hyperthyroidism where both etiologies coexist. The presence of hyperfunctioning nodules in Graves’ disease patients ranges between 0.8 and 4.3%.

Clinical case: We present three cases of Marine–Lenhart syndrome, all in female patients, aged 40–57 years old at the time of diagnosis. All cases had positive titers of anti-thyroid antibodies and thyrotropin receptor antibodies (TRAbs). The thyroid scans showed diffuse uptake with one or more hyperfunctioning nodules, without attenuation of the surrounding areas. One of the cases represents the occurrence of hyperthyroidism after treatment of toxic nodular goiter with radioactive iodine.

Discussion: The described cases present criteria for the diagnosis of Marine–Lenhart syndrome. Graves’ disease is more frequent in younger individuals, while Marine–Lenhart syndrome occurs in older ones, as occurs in Plummer’s disease. As these are cases that tend to recur, total thyroidectomy is the treatment of choice.

Conclusions: Marine–Lenhart syndrome is a controversial cause of hyperthyroidism. The importance of its diagnosis resides in the preference for surgical treatment.