Endocrine Abstracts

Introduction: Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy (80%), while primary thyroid lymphomas (PTL) occur in only 0.6–5% of cases. A significant number of PTCs, as well as PTLs, arise in the setting of Hashimoto’s thyroiditis (HT), however the simultaneous occurrence of these two malignancies is extremely rare.

Case report: We present a 34-year-old female patient with thyroid MALT lymphoma and coexisting papillary microcarcinoma (PMC) in the setting of HT in the contralateral lobe that was admitted to our Institution for thyroid surgery. Patient had no compressive symptoms or lymphoma-related symptoms. Physical and ultrasonical examination in our Institution showed euthyroid multinodal goitre with pre-laryngeal medial neck mass (position of pyramidal lobe) and negative regional lymph nodes. Additionally, patient had increased antibodies’ level. Preoperative fine-needle aspiration biopsy of pyramidal lobe tumour showed HT. Patient was submitted to total thyroidectomy with sentinel lymph node biopsy of jugulo-carotid regions after 1%-methylene blue dye injection. Histopathology analysis showed MALT lymphoma in the right lobe and HT with incidental PMC in the left lobe. Lymph nodes were diagnosed as benign, with reactive sinus histiocytosis. Postoperative whole body scintigraphy with radioiodine 131 was negative and substitutional-suppressive therapy with levothyroxine was initiated. Complete multidisciplinary diagnostic evaluation for MALT lymphoma was performed with confirmation of PTL stage IE, thus no further therapy was conducted. Ten months after surgery, presented patient is without recurrence.

Conclusions: Optimal management of coexisting PTC and MALT lymphoma depends on stage of both diseases at the initial presentation. In patients with HT, attention should be focused on frequent concomitant PTCs and possible occurrence of lymphomas, thus total thyroidectomy represents a therapy of choice.