Synchronous Occurrence of Papillary Thyroid Carcinoma and Mucosa-Associated Lymphoid Tissue Lymphoma: a Single Case Report

ABSTRACT

Papillary thyroid carcinoma (PTC) is a common lesion, accounting for 70-80% of all thyroid cancers, whereas mucosa-associated lymphoid tissue (MALT) lymphoma of thyroid gland is rare. A simultaneous occurrence of both malignancies is extremely rare. 57 years old Korean woman diagnosed with Hashimoto's thyroiditis at left lobe of thyroid gland where atypical cells of undetermined significance at right lobe. Later, left lobe was confirmed with malignant lymphoma during series of fine-needle aspiration biopsy. Right lobe was interpreted as malignant lesions, such as papillary thyroid carcinoma based on ultrasonography images and previous biopsy results. Total thyroidectomy was performed. Pathology reported papillary thyroid carcinoma at right lobe and MALT lymphoma at left lobe. There were no post-operative complications and no recurrence yet reported. Since an association between Hashimoto's thyroiditis and development of MALT lymphoma has been reported previously, a history of Hashimoto thyroiditis should be suspected MALT lymphoma.