E-Poster Presentation ESA-SRB-ANZBMS 2021

An unusual growth in the thyroid (#367)

Lauren Burrage 1 , Brett Sillars 1
  1. Endocrinology , Sunshine Coast Health Service, Sunshine Coast, Queensland, Australia

A 69-year-old female with a background of Hashimoto’s thyroiditis presented to endocrinology clinic with a rapidly enlarging neck mass. She had no B symptoms of malignancy. On examination she had an unusually firm goitre. Ultrasound and computed tomography demonstrated an enlarged thyroid with abnormal diffuse spongiform appearance without discrete nodules. Thyroid lymphoma was suspected clinically and FNA with flow cytometry and subsequent core biopsy confirmed the diagnosis of high-grade B-cell lymphoma. Bone marrow aspirate and trephine (BMAT) was negative, and fluorodeoxyglucose-positron emission tomography (FDG-PET) excluded advanced disease (see Figure 1a). Treatment with four cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone followed by adjuvant radiotherapy resulted in complete metabolic response. Figure 1b demonstrates the post-treatment FDG-PET which reveals minor residual thyroid uptake, likely related to underlying Hashimoto’s disease.

 

Primary thyroid lymphoma has an incidence of 2 cases per million persons and accounts for 2% of extra-nodal lymphomas and <5% of thyroid malignancies.1,2 It is more common in females and has a median age of diagnosis of 65 years.2 The only established risk factor is Hashimoto’s thyroiditis which confers a 60-fold increased risk.1 The majority of primary thyroid lymphomas are diffuse large B-cell lymphomas.1,3 Diagnosis is made with core biopsy and staging requires BMAT and FDG-PET.2,3 80% of patients have limited disease with 5-year overall survival of >80%.2 Treatment is typically with chemotherapy and radiotherapy which improves survival compared with chemotherapy alone.2 The addition of rituximab also significantly improves survival.2,4 Surgery is seldom required and does not affect outcomes.2,5 Even patients with severe obstructive symptoms rarely require surgery as prednisolone rapidly improves such complications, including airway compromise.2,3

 

Primary thyroid lymphoma is an important diagnosis to consider as rapid growth can result in significant compressive complications. Prognosis is favourable but treatment is distinctly different from the usual management of thyroid malignancy.

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  1. Bai Z, Li L, Guan T, Wang J, Zhao J, Su L. Clinical prognosis and bioinformatic analysis of primary thyroid lymphoma. Medicine. 2021. 12;100(6):e24598.
  2. Yi J, Yi P, Wang W, Wang H, Wang X, Luo H and Fan P (2020) A Multicenter Retrospective Study of 58 Patients With Primary Thyroid Diffuse Large B Cell Lymphoma. Front. Endocrinol. 11:542. doi: 10.3389/fendo.2020.00542.
  3. Kesireddy M, Lasrado S. Thyroid Lymphoma. 2021. StatPearls Publishing.
  4. Watanabe N, Narimatsu H, Noh JY, Kunii Y, Mukasa K, Matsumoto M, Suzuki M, Sekiya K, Ohye H, Yoshihara A, Iwaku K, Kobayashi S, Kameyama K, Kobayashi K, Nishikawa Y, Kami M, Sugino K, Ito K. Rituximab-including combined modality treatment for primary thyroid lymphoma: an effective regimen for elderly patients. Thyroid. 2014 Jun;24(6):994-9.
  5. Pyke CM, Grant CS, Habermann TM, Kurtin PJ, van Heerden JA, Bergstralh EJ, Kunselman A, Hay ID. Non-Hodgkin's lymphoma of the thyroid: is more than biopsy necessary? World J Surg. 1992;16(4):604-609.