A 66-year-old woman with a history of Hashimoto's thyroiditis and thyroid nodules initially presented for fine needle biopsy (FNB). Patient had no symptoms of hypothyroidism or hyperthyroidism. Her initial TSH was 5.9 IU/L (ref 0.27–4.20) with FT4 1.2 ng/dL (ref 0.89–1.76) (Fig. ) and thyroperoxidase (TPO Ab) and thyroglobulin (TG Ab) antibodies were 18,290 IU/mL (ref 0–34) and >2,250.0 IU/mL (ref 0.0–0.9) (Fig. ), respectively. Additionally serum thyroid stimulating immunoglobulin (TSI) level was 88% (ref 0–139) and thyrotropin receptor blocking antibody (TBRAb) (Fig. ) was also in the normal range (<10%, ref <10). Physical examination revealed normal vital signs and patient had no evidence of thyroid orbitopathy. Examination of the thyroid gland confirmed a 2-cm right lower lobe thyroid nodule and a 6-cm left thyroid nodule almost replacing the left lobe. Thyroid ultrasound showed multiple thyroid nodules bilaterally with a dominant hypervascular left thyroid mass 5.9 × 2.7 × 4.4 cm (Fig. ) and a right lower lobe nodule 2.4 × 2.4 × 2.2 cm. Additionally an ultrasound of the neck confirmed bilateral abnormal cervical lymphadenopathy. FNB of the thyroid nodules revealed a population of large lymphocytes with irregular nuclei (Fig. ). Fluorescence in situ hybridization (FISH) revealed a translocation t(14;18), fusing the immunoglobulin heavy chain gene at chromosome 14q32 with BCL2 gene at chromosome 18q21.3. Positron emission tomography computerized axial scan (PET-CT) of the chest and abdomen revealed a large retroperitoneal and mesenteric soft tissue mass, measuring 16 × 14 cm in greatest trans-axial dimension. The retroperitoneal mass encased the aorta and inferior vena cava as well as mesenteric vessels and both renal arteries. The mass also displaced the kidneys peripherally (Fig. ). She was diagnosed with stage-IVE diffuse large B-cell lymphoma (DLBCL) and underwent six cycles of R-CHOP chemotherapy. Patient also received subdiaphragmatic external radiation directed to the retroperitoneal mass. Following chemotherapy, and radiation therapy, PET-CT scan showed resolution of retroperitoneal mass, resolution of fluorodeoxy-glucose (FDG) avid thyroid nodule (Fig. ) as well as no evidence of thyroid nodules on repeat ultrasound. Following chemotherapy her thyroid functions normalized (serum TSH 3.9 IU/L and free T4 1.4 ng/dL). A moderate decrease in thyroid peroxidase Ab (range 8,432 to 11,288 IU/mL) and thyroglobulin Ab (range 1,268 to 1,600 IU/mL) were noted. Additionally TSI 88% and TBRAb <10% (ref <10) (Fig. ) continue to remain in the normal range. She remained euthyroid without any symptoms of hypo or hyperthyroid and her serum TSH and free T4 remained normal for the next 2 years (Fig. ). Additionally she had no evidence of lymphoma recurrence.\nTwo years later, patient reported significant unintentional weight loss and persistent fatigue over the past couple months. Physical examination revealed a heart rate of 120/min, fine tremors of outstretched fingers, and no thyroid orbitopathy. Thyroid was 40 g in size with no palpable nodules and deep tendon reflexes were brisk. Repeat laboratory testing revealed: TSH 0.005 IU/L, FT4 6.73 ng/dL and TSI 535% (Fig. ). Serum TBRAb was also mildly elevated (28%). TPOAb and TGAb levels were 7,976 and 1,088 IU/mL respectively (Fig. ). Additionally, an HLA DQB1*03 was positive. Further evaluation confirmed the diffuse large B-cell lymphoma (DLBCL) lymphoma was in remission. A thyroid uptake and scan showed diffuse uptake with no photopenic areas and the I131 uptake was elevated (4 h: 61.0%, reference 5–15%, at 24 h 70.3%, reference 10–30%).\nSince patient received CAT scan with iodine load she was treated with methimazole for 3 months and following this, the patient was treated with 19.4 millicuries of radioactive iodine for thyroid ablation. Following radioactive iodine treatment patient developed hypothyroidism and this was treated with levothyroxine (Fig. ). Patient remained euthyroid for the next 4 years and during these 4 years the lymphoma continues to remain in remission.
A 60-year-old lady, presented with tremulousness of hands for 1 month and palpitation with excessive sweating for 3 months. She had a history of weight loss for 6 months, and gradually enlarging neck swelling for 3 years. She was nervous, irritable, and emotionally labile. Her weight was 46 kg, BMI 17, afebrile, pulse rate: 110/min/regular, blood pressure: 140/56 mm of Hg. Her thyroid gland was symmetrically enlarged, firm in consistency, nodular/lobular surface and mildly tender without any bruit. Palms were warm and sweaty with fine tremor in hands. All reflexes were exaggerated. There were no occular manifestations.\nInitial thyroid function tests (TFT) revealed high T3: 3.80 ng/ml (0.80-2.10), T4: 12.40 ug/dl (5.10-12) with a low TSH: 0.20 mU/L (0.70-5). Her TSH receptor antibody (TSAb): 25 U/L (Normal [nl.] <1), anti TPO antibody: 374 IU/ml (nl. <35) and thyroglobulin antibody: 268 IU/ml (nl. <65) were all strongly positive. Complete hemogram and ESR-18 mm/h (nl.-1-25) were normal. Ultrasonogram of thyroid revealed an enlarged gland with hypoechoic parenchyma with fibrous septa.99mTc pertechnetate scan (Tc99m scan) revealed enlarged thyroid gland with diffusely increased uptake of radiocontrast: 17% (nl. 0.4-4%) with some patchy defects in both lower poles. Thyroid FNAC showed sheets of Hurthle cells with abdunce of lymphocytes and sheets of regular follicular cells, indicating HT. She was observed on beta blockers. Repeat TFT, 3 months later showed: T3: 4.20 ng/ml, T4: 14.40 ug/dl, TSH: 0.001 μU. Repeat 99mTc pertechnetate scan was done, which again revealed enlarged thyroid gland with diffusely increased uptake of radiocontrast: 21% (nl. 0.4-4%) with same patchy defects in both lower poles. Antithyroid medication carbimazole was started.