Concurrent Abdominal and Thyroid Lymphoma: A Case Report

Objective: Thyroid lymphoma constitutes a rare presentation of extranodal, diffuse, large B-cell lymphoma (DLBCL) and represents a small proportion of thyroid cancers. In this article, we present a case report of extranodal DLBCL presenting with simultaneous thyroid, abdominal, and retroperitoneal involvement. We also review the relevant epidemiologic literature and treatment modalities of thyroid lymphoma as well as providing a potential pathophysiologic mechanism. Methods: A literature search was conducted using the databases PubMed and Google Scholar for primary thyroid lymphoma and extranodal lymphoma involving the thyroid. Publications were selected based upon size of patient cohorts, treatment modalities investigated, quality of the data, as well as subsequent citation frequency. Articles most recently published, and therefore belonging to the post-rituximab era, were favored. Results: Thyroid lymphoma in the presence of concurrent abdominal disease usually presents with goiter with or without symptomatic hypothyroidism and some combination of early satiety, dysphagia, dyspepsia, or weight loss. Disease limited to the thyroid is typically treated with surgery and radiation, while extensive disease is typically treated with chemoimmunotherapy. The shared embryologic origin between lymphocytes in the thyroid and those in the abdomen may contribute to simultaneous development of lymphoma in the setting of autoimmune lymphocytic thyroiditis and resulting alterations in systemic cytokines. In this case, the patient had a complete response to chemoimmunotherapy and remains in remission. Conclusion: This case highlights an unusual presentation of concurrent abdominal and thyroid DLBCL. Higher stage disease portends a worse prognosis, though our patient is without evidence of residual disease 2 years after diagnosis.