Thyroid nodule: first manifestation of chronic lymphocytic leukaemia

Ana Gonçalves, Sara Vale, Ema Nobre, Ana Paula Barbosa, Ema Piloto, Ana Wessling, Mário Mascarenhas

The presence of chronic lymphocytic leukaemia (CLL) cells in the thyroid gland is most likely due to a secondary involvement by a systemic disease. The reported incidence of CLL involving the thyroid is extremely low, representing about 3-4% of all thyroid lymphoproliferative neoplasm. We report a rare case of CLL presenting initially in the thyroid gland. Systemic disease was detected as a result of thyroid investigation. An 85 years old woman, with multinodular goiter without adenophaties, was referred to our department, carrying a fine needle aspiration biopsy (FNAB) report of a private institution referring "lymphoid monomorphic proliferation" and suggesting a "Core-needle biopsy" for further investigation. She was euthyroid (TSH-0.5 uU/mL (0.4-4.0), thyroid antibodies negative, including TRab). The patient denied systemic symptoms and at physical examination there were no adenophaties or organomegalies. FNAB analysis was repeated. Although the patient denied constitutional symptoms and there were no relevant findings in physical examination, technetium 99m thyroid gamagraphy (GG) and blood count were additionally asked. FNAB analysis concluded lymphocytic tiroiditis, but thyroid GG revelled global hypocaptation and blood count showed 173.4 x 109 leukocyte/L with 94% lymphocyte. An ecoguided FNAB with flow cytometry identified thyroid infiltration by monotonous population of blasts with phenotype consistent with CLL/malignancy of mature B-cells. CLL/malignancy of mature B-cells was also detected in peripheral blood analysis, suggesting systemic disease with secondary thyroid involvement. The patient started chemotherapy with rituximab and chlorambucil with good response. Pos-treatment GG revelled "Increased levels of uptake in the middle third of the right lower lobe, with low uptake of the remaining parenchyma". In conclusion, good communication with the pathologist can improve diagnostic accuracy and dictate appropriate therapy. The use of techniques such as flow cytometry, immunoglobulin gene rearrangements, and immunohistochemistry has improved diagnostic accuracy and obviated more invasive procedures, such as core needle or open surgery biopsy. Apart from chemotherapy, immunochemotherapy with anti-CD20 and anti-CD52 monoclonal antibodies can be used in the treatment of CLL.