Endocrine Abstracts

Thyroid nodules are very common findings in clinical practice. Only a fraction of these thyroid nodules are malignant and reliably differentiating those remains a challenge. We present a case of a man who presented with an enlarging neck mass causing compressive symptoms. This was diagnosed as a multinodular goitre (MNG). However, histopathological analysis revealed it to be diffuse large B-cell non-Hodgkin lymphoma (DLBCL). A 50-year-old male was referred to our endocrinology service by primary care through the 2-week-wait referral system. He had a background of congenital deafness, asthma and retinitis pigmentosa for which he was registered as blind. He had an 8-week history of a neck lump with compressive symptoms including dyspnoea and dysphagia. A collateral history from his mother confirmed the sub-acute onset of the neck lump. He was seen by primary care and an ultrasound (US) scan was done prior to referral to endocrinology. This revealed multiple thyroid nodules, the largest measuring 49 × 37 × 35 mm and graded as U3 indeterminate. He was seen in our service within 2 weeks of the referral. On examination of the neck, there was a large irregular goitre which was rather firm and moved only slightly on swallowing. His thyroid function tests were normal. He had a repeat US neck done that revealed a large hypoechoic mass involving both thyroid lobes measuring 4.7 × 5.5 cm on the left and 2.3 × 3.4 cm on the right side in axial diameter. The mass showed only minor internal vascularity on colour Doppler. There was US evidence of right sided lymphadenopathy measuring at least 1.4 cm in short axis diameter. The mass was extending into the isthmus with tracheal deviation. This was graded as a U5 nodule and hence a fine needle aspiration cytology (FNAC) was performed using an aseptic technique. Given the extent of the mass, a computed tomography (CT) was arranged and revealed a lobulated homogenous cervical mass surrounding the thyroid gland and supraclavicular fossae, extending into the anterior mediastinum. The FNAC was reported as CD-20 positive lymphoid cells, suggesting DLBCL. He was referred to haematology and has since received 6 rounds of chemotherapy and 15 rounds of radiotherapy. Although there have been case reports of non-Hodgkin’s lymphoma of the thyroid, we present a unique case where DLBCL presented as MNG which, on further investigation, was found to be a cervical mass encircling the gland and masquerading as MNG.