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 43 year old obese female, married, mother of 4 children was diagnosed as having hypothyroidism in the beginning of year 2011 when she felt lethargic and her TSH level was raised to 72 uIU/ml. She was started on thyroxine 150 mcg/day which was later on decreased to 100 mcg when her TSH level was suppressed to 0.5 uIU/ml after 1 month. After further 4 weeks her serum TSH came out to be further suppressed at <0.005 uIU/ml so thyroxine was stopped. The patient came for follow up after 8 weeks with serum TSH of 0.2 uIU/ml and T4 of 16.20 ng/dl (4.5-11.3). She then lost to follow up and returned in September 2011 with Thyroid function test showing serum TSH of <0.005 uIU/ml and FT4: 2.36 ng/dl. Thyroid antibodies were strongly positive. At this time she also had complained of palpitations, increased appetite, increased bowel movements, decreased sleep and tremors of hands. On examination she had no goiter and eye signs but had fine tremors of hands. She was advised to start carbimazole.