Primary Thyroid Lymphoma Arising in a Background of Hashimoto Thyroiditis, A Rare Case of Marginal Zone B Cell Lymphoma

Primary thyroid lymphoma (PTL) is very rare and as per definition it is a lymphoma involving the thyroid gland alone or non-contiguous lesions involving thyroid gland and lymph nodes. (1) Localized thyroid lymphomas have a good outcome. The outcome depends also on the type of the lymphoproliferative disorder. We present a case of an 83-year-old lady who presented with diffuse neck swelling for 2 years with a recent increase in size over the past 3 months. Total thyroidectomy was done and the histopathology revealed Hashimoto thyroiditis with lymphoproliferative disorder. IHC was done and a diagnosis of Marginal zone B cell lymphoma was made.