1. IntroductionLymphoma of the thyroid gland constitutes 3% of all non-Hodgkin’s lymphoma and 5% of all thyroid malignancies. Autoimmune disease, including systemic lupus erythematosus, increases the risk of lymphoma, (1-2) in particular, the risk of developing thyroid lymphoma in patients with Hashimoto’s thyroiditis is 40 to 80 times greater than that of the general population. (3) The incidence of pre-existing autoimmune thyroiditis or Hashimoto’s thyroiditis in patients with thyroid lymphoma has been reported at 27-100% in previous studies. (4-6) Diffuse large-cell lymphoma is the most common type of thyroid lymphoma. Patients usually present with a rapidly growing mass in the neck, causing local obstructive and infiltrative symptoms such as hoarseness, dysphagia, or dyspnea. Review of the histopathology reveals lymphoid cells that can be difficult to distinguish from autoimmune thyroiditis which can cause misdiagnosis due to the low yield of fine needle aspiration. We present a rare case of primary thyroid diffuse large B cell lymphoma initially felt to have lymphocytic thyroiditis in a patient with Hashimoto’s thyroiditis and SLE.

1. Introduction:Postpartum autoimmune thyroiditis typically presents within one year following delivery and exhibits a prevalence of 8% in the general population. However, this incidence significantly escalates to 20% among individuals with a history of type 1 diabetes or a familial predisposition to thyroid disorders.(1) Lymphocytic hypophysitis (LH) is a rare condition characterized by inflammation of the pituitary gland that usually affects women during the last trimester of pregnancy or the first six months after delivery. (2) Two autoimmune conditions prominently manifest in connection with pregnancy: postpartum autoimmune thyroiditis and autoimmune hypophysitis. We present an extremely rare incidence of thyroid storm due to postpartum thyroiditis followed by the surprising diagnosis of lymphocytic hypophysitis, leading to panhypopituitarism.