Endocrine Abstracts

We present the case of a patient with a diagnosis of thyroid cancer who has developed multiple, sequential autoimmune conditions. Our patient, a now 41 year-old female, was initially diagnosed with Follicular Thyroid Cancer in the context of pre-existing autoimmune hypothyroidism evidenced by serum Anti-Thyroid Microsomal antibodies as well as lymphocytic thyroiditis on post-operative histopathology. The association between autoimmune thyroid disease and Thyroid Cancer has been previously described. Following total thyroidectomy, she underwent radioactive iodine ablation at our centre and in the years post-treatment, she has maintained a sustained response to therapy although she has developed new Thyroglobulin Antibody positivity. 3 years post initial presentation, she developed Parietal-cell Antibody-positive pernicious anaemia, requiring parenteral B12 replacement. 9 years post-treatment, she developed seizures and memory loss prompting neurological assessment and diagnosis with Autoimmune Temporal Lobe Epilepsy secondary to Glutamic Acid Decarboxylase (GAD) Antibody-positivity. She demonstrated a high tire GAD >2000 (Reference range: 0.00-9.99). GAD autoimmunity has been linked to a number of conditions which include but are not limited to: Stiff-Man-Syndrome and Type 1 Diabetes Mellitus (T1DM), autoimmune hypothyroidism and pernicious anaemia. Given her initial endocrinopathy, we have opportunistically screened this patient for the emergence of T1DM with Islet Cell Autoantibodies which have been positive but HbA1c and C-peptide levels have consistently been normal. This case illustrates a unique sequence of clinical manifestations of multiple autoimmune conditions in a predisposed individual. While the autoimmune linkages are well recognised, this clinical pattern has not been previously described.