Coexistence of tuberculosis and extranodal marginal zone lymphoma of the thyroid gland: Case report and literature review.

Introduction: Primary thyroid tuberculosis (TB) is rare even in countries where TB disease is endemic, with the prevalence ranging from 0.1 to 1.15%. Primary thyroid lymphoma is uncommon, and the majority of lymphomas arising in the thyroid gland are non-Hodgkin's lymphomas of B-cell origin, of which about 25% is extranodal marginal zone B cell lymphoma (MALToma). Case presentation: An 86-year- old Turkish female patient with thyroid nodules and cervical lymphadenopathies presented with large multinodular goiter and compressive symptoms. Total thyroidectomy and central lymph node dissection were performed. The revised histological and immunohistochemical revealed the coexistence of thyroid TB and MALToma. The patient received an anti-TB treatment for six months before a revised histopathological examination. About seven months after anti-TB treatment, the patient died due to an unknown cause. Clinical discussion: Although six cases of thyroid TB and papillary thyroid cancer have been documented in the medical literature, no cases of TB and MALToma coexistence have been published so far, to our knowledge. Another essential feature of this study is that the initial pathological examination was reported as thyroid TB. A subsequent re-examination revealed that the patient had both TB and MALT lymphoma. Conclusion: We discuss this rare association and the dilemma encountered in the diagnosis and management of this patient with a review of the literature.