Endocrine Abstracts

Primary Thyroid Lymphoma is rare comprising less than 5% among all thyroid malignancies. It is historically associated with Hashimotos thyroiditis. It typically presents as a rapidly enlarging, painless goitre resulting in compression symptoms. Thyroid ultrasound and FNA cytology, using flow cytometry and immunohistochemistry, remain the primary modalities to confirm the presence of lymphoma. Treatment depends on the immunohistology. The prognosis is subtype depended and is generally good. A 53 years old female was seen in the Endocrine clinic with a right sided neck lump. On examination a smooth enlarged right thyroid lobe was noted. Her history suggested Hashimoto’s thyroiditis but she has an enlarged right thyroid lobe. Biochemically her TSH was 11.87 with a FT4 being low/normal at 13. She had positive TPO antibodies. She was referred for a Fine needle aspiration of the right lobe demonstrated lymphoid cells consistent with lymphocytic thyroiditis and was started on Levothyroxine 50mcg as she was symptomatic and an interval scan was recommended in 3 months’ time. She was seen in a 4 months’ time with her scan results and her right sided thyroid swelling appeared to have increased in size. A repeat ultrasound scan confirmed an increase in size compared to previous scans with level 6 and 4 lymph nodes. A core biopsy showed features consistent with an Extranodal marginal zone lymphoma (MALT-type). A staging CT showed stage 2E with FDH avid right thyroid lobe and 4 cervical lymph nodes of 10mm. A bone marrow aspiration showed no lymhomatous infiltrate. She underwent a radical radiotherapy with 24 Gy in 12 fractions with good effect. A repeat PET CT scan showed no residual disease. This case demonstrates that a rapidly enlarging thyroid lump should be investigated urgently to facilitate early diagnosis of the underlying cause, Thyroid lymphoma being one of them.