Rapidly Growing Goitre: Not Always A Carcinoma.

Primary thyroid lymphoma (PTL) is a rare malignancy of the thyroid gland which should be considered in patients with a rapidly growing cervical mass, especially in those with a history of Hashimoto's thyroiditis. We present the case of a 53-year-old woman with a rapidly growing goitre with compressive symptoms. Computed tomography (CT) imaging was performed to examine the extent of disease and a biopsy showed B-cell non-Hodgkin lymphoma, stage I according to the Ann Arbor classification. The patient was immediately treated with high-dose prednisone for her compressive symptoms and after the diagnosis she received six cycles of R-CHOP (rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone) chemotherapy. The patient has now been in remission for 12 months. We present this case to demonstrate the importance of awareness of PTL. Up to 10% of cases can be missed with fine needle aspiration cytology (FNAC), making it important to obtain a histological biopsy in rapidly growing goitres. In addition, establishing the correct diagnosis can in most cases prevent unnecessary surgical intervention. The preferred treatment with the best overall survival is chemotherapy with or without radiation therapy. LEARNING POINTS: Primary thyroid lymphoma is a rare malignancy of the thyroid gland which should be considered in rapidly growing goitres, especially when there is a history of Hashimoto's thyroiditis.A histological biopsy is preferred to minimize misdiagnoses.Surgical intervention can typically be avoided with correct diagnosis and with the use of corticosteroids to reduce compression symptoms.