Normalization of lymphocyte count after high ablative dose of I-131 in a patient with chronic lymphoid leukemia and secondary papillary carcinoma of the thyroid. Case report

Abstract

The authors report the case of a 70-year-old male patient with chronic lymphoid leukemia who presented subsequently a papillary carcinoma of the thyroid with metastases to regional lymph nodes. The patient was treated with surgical thyroidectomy with regional and cervical lymph node excision and radioiodine therapy (I-131). The protocolar control scintigraphy 4 days after the radioactive dose showed I-131 uptake in both axillae and even in the inguinal regions. PET/CT showed faint FDG-F-18 uptake in one lymph node of the left axilla. An ultrasound guided fine needle biopsy of this lymph node identified by I-131 SPECT/CT and FDG-F-18 PET/CT revealed lymphoma cells and was negative for thyroid tissue and thyroglobulin content. The sequential blood counts done routinely after radiation treatment showed a marked fall until return to normal values of leucocytes and lymphocytes (absolute and relative), which were still normal in the last control 19 months after the radioiodine administration. Chest computed tomography showed a decrease in size of axillary and paraaortic lymph nodes. By immunohistochemistry, cells of the lymphoid B lineage decreased from 52% before radioiodine therapy to 5% after the procedure. The authors speculate about a possible sodium iodide symporter expression by the cells of this lymphoma, similar to some other non-thyroid tumors, such as breast cancer cells.

Diffuse Bone Uptake of 131I and Effect on Blood Counts in a Patient With Papillary Thyroid Carcinoma and Chronic Lymphocytic Leukemia

“…[4][5][6][7][8] A case of untreated CLL with differentiated thyroid cancer was reported in 2014. 9 A 70-year-old patient was administered a single dose of 200 mCi of 131 I after total thyroidectomy for remnant ablation. Postdose whole-body scintigraphy revealed axillary and inguinal CLL-related nodes.…”

“…As iodine uptake is mediated by the sodium-iodine symporter in thyroid and breast cancer, 10 it is hypothesized that some lymphoma cells may as well express sodium-iodine symporter. 9 Moreover, using primarily antibody vectors, leukemic cells were shown be sensitive to beta emission when exposed to 131 I, 11 thus explaining the drop of white blood cells after exposure. To our knowledge, this is the first presentation of diffuse accumulation of 131 I inside bone marrow in a posttherapeutic scintigraphy in relation with CLL, acting as a challenging and rare pattern during routine interpretation.…”

“…White blood cells and platelets are known to decrease significantly during the year following irradiation 4–8 . A case of untreated CLL with differentiated thyroid cancer was reported in 2014 9 . A 70-year-old patient was administered a single dose of 200 mCi of 131 I after total thyroidectomy for remnant ablation.…”

“…Our case shows an additional and undescribed diffuse osteomedullary and splenic uptake, as well as a similar trend of lymphocyte count over time. As iodine uptake is mediated by the sodium-iodine symporter in thyroid and breast cancer, 10 it is hypothesized that some lymphoma cells may as well express sodium-iodine symporter 9 . Moreover, using primarily antibody vectors, leukemic cells were shown be sensitive to beta emission when exposed to 131 I, 11 thus explaining the drop of white blood cells after exposure.…”