Endocrine Abstracts

Introduction: The diffuse large B-cell lymphoma (DLBCL) is known as one of the most common lymphoma worldwide with the prevalence of 25 % of all of non-Hodgkin lymphoma cases [1], but it is very rearly observed in thyroid. Around 30 % of Clinical cases of the DLBCL appear from extranodal organs, the prognosis depends on the site of origin [2].

Case: A 18-year-old man was admitted to endocrinologist, complaining with a palpable nodule in the front neck for about 2 months. Patient has never been diagnosed with any thyroid disease before.Diagnostic tests: Laboratory tests: Euthyroid chronic autoimmune thyroiditis was diagnosed TSH 2.3 (normal range 0.4-3.6) IU/l, FT4 12.2 (9.0-21.07) pmol/l, FT3 5.9 (3.34-5.1) pmol/l, ATPO 823 (0-3.2) kIU/l).Thyroid ultrasound A hypoechoic, ill-defined margin, calcificated nodule was visible in the left lobe of the thyroid gland (EU-TIRADS 5).Microscopic examination A core needle biopsy of the left thyroid lobe identified diffuse large B-cell non-germinal center lymphoma as diffused lymphoid infiltration of mitotically active cells with large irregular-contoured nuclei and sparse cytoplasm with positive LCA immunolabeling and negative MyoD1.

PET/CT scan: A 3.3 x 6.2 x 7.3 cm of polysegmental, FDG - accumulating lymphoma mass was observed in the left lobe of the thyroid gland. There were no visible metabolically active lymph nodes, infiltrative changes in the lungs and pathological foci in the bones.

Treatment: Treatment consisting of immunotherapy with Rituximab and immunochemotherapy with regimen R-CHOP was initiated. Patient received Filgrastim and Prednisolone for neutropenia prophylaxis. No complications have been observed.

Conclusion: The prevalence of lymphoma in thyroid is very rear, still the early diagnosis and specific treatment is crucial for proper management of the disease, as non-germinal center type large B-cell lymphoma is usually associated with a higher mortality rate compared to germinal center large B-cell lymphoma [3].

References1. Freedman SA, Aster CJ. Epidemiology, clinical manifestations, pathologic features, and diagnosis of diffuse large B cell lymphoma. UpToDate. 2022. 2. Ollila TA, Olszewski AJ. Extranodal Diffuse Large B-Cell Lymphoma: Molecular Features, Prognosis, and Risk of Central Nervous System Recurrence. Curr Treat Options Oncol. 2018. 3. Patil N, Girgis M. Outcome of germinal center B-cell type compared to non-germinal center/activated B-cell type diffuse large b-cell lymphoma as determined by immunohistochemistry using the Hans algorithm. 2020.