An important treatable differential for anaplastic thyroid carcinoma.
A Abbara, M Reddy, S Partridge, D Darko, WM Kong, D Devendra
Central Middlesex Hospital.
A 68 year old polish gentleman was referred to the Ear Nose and Throat department with a progressive history of dysphagia and dysphonia over the previous month. He described a choking sensation whilst swallowing food and noted a change in the quality of his voice, but denied weight loss or night sweats. He also reported an enlarging swelling in the region of the right supra-clavicular fossa. His past medical history included a previous shoulder dislocation and varicose vein surgery. His thyroid function tests were normal.
In view of his dysphagia a barium swallow was arranged. This demonstrated deviation of the oesophagus due to extrinsic compression in the region of the thoracic inlet, suggestive of a right para-tracheal mass. An ultrasound of the neck established a markedly enlarged thyroid gland, which was hypoechoic and heterogenous, although without increased vascularity, calcification or focal nodules. A CT scan of the neck, thorax, abdomen and pelvis confirmed that the thyroid was grossly enlarged (8.3x5.5x11.4cm) and that normal thyroid tissue had been replaced by abnormal solid tissue. The trachea was deviated to the left and was compressed at the mid-cervical level. There was bilateral lymphadenopathy in the neck (levels 4 and 5), supraclavicular, pre- and para-tracheal regions of the mediastinum. However no liver or intra-abdominal spread was noted.
An FNA demonstrated numerous intermediate and large atypical lymphocytes with occasional intermingled small mature lymphocytes. No colloid or follicular epithelial cells were identified. The appearances were consistent with high-grade Non Hodgkins lymphoma (Thy 5).
Primary thyroid lymphoma is an uncommon malignancy, accounting for less than 5% of thyroid malignancies and ~2% of extra-nodal lymphomas. It has a peak incidence in the sixth decade and is more common in females (3:1). Thyroid lymphoma (especially MALT-oma) occurs 40-80 times more commonly in patients with previous Hashimoto’s thyroiditis. It commonly presents with a rapidly enlarging mass, which may lead to compressive symptoms. The vast majority are of B cell origin with 70% of cases being Diffuse Large B cell Lymphomas, with the second most common type being MALT-oma (1). Treatment is determined by the histology of thyroid lymphomas, but usually comprises of chemotherapy with or without radiotherapy. This presentation represents an important differential diagnosis for anaplastic carcinoma of the thyroid which may be more amenable to therapeutic interventions.
(1) A Rare Case of Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma Presenting in the Thyroid GlandJoyce Shin, Deborah Chute, Mira Milas, Jamie Mitchell, Allan Siperstein, Eren Berber Thyroid. September 2010, 20(9): 1019-1023