Introduction: Lymphomas account for <5% of thyroid malignancies. The vast majority of them are non-Hodgkins lymphomas (NHL), especially mucosa-associated lymphoid tissue lymphomas (MALT) and diffuse large B-cell lymphomas (DLBCL). However, Hodgkins lymphoma affecting thyroid gland is very rare. Worldwide has been reported <50 cases so far and we describe another one.
Case report: A 22-year-old woman was referred to our department of endocrinology for a rapid enlargement of thyroid gland. Prior short therapy of corticosteroids soothed the growth, but after its cessation the goitre enlarged causing dysphagia, dry cough and stridor. The patient also suffered with night sweats and intermittent fever. Both physical and ultrasound examination found unilaterally large hypoechoic right thyroid lobe, deviating trachea to the left and at least two suspicious supraclavicular lymph nodes along the right sternocleidomastoid muscle. According to laboratory the patient was euthyroid, thyroid antibodies were negative, no significant changes in blood count. Elevated was lactate dehydrogenase (LDH 6 μkat/l), C-reactive protein (CRP 53 mg/l), erythrocyte sedimentation rate (ESR 76 mm/first hour). The fine-needle aspiration cytology (FNAC) was highly suspicious of lymphoma, but the flow cytometry did not prove any abnormal population of lymphocytes consistent with non-Hodgkins lymphoma. Therefore a diagnostic excision from the right thyroid lobe was performed. Final diagnosis of classical Hodgkins lymphoma, nodular sclerosing subtype was established. The department of haematology classified our patient for advanced stage IIB+E (extranodal involvement). The patient was treated with six cycles of eBEACOPP chemotherapy, reaching total remission according to PET/CT scan, further radiotherapy was not indicated.
Conclusion: Hodgkins lymphoma of thyroid is rare, rapid growth can mimic primary thyroid carcinoma, FNAC can mimic thyroiditis, lacking diagnostic Reed-Sternberg cells. Flow-cytometry is not helpful in Hodgkins disease. A biopsy is usually necessary to confirm the right diagnosis.