7008 Challenges in the Management of Thyroid Lymphoma - Case Report

Abstract Disclosure: F. Toloza Bonilla: None. P. Veeraraghavan: None. R. Lakhotia: None. M. Roschewski: None. N. Nilubol: None. S. Gubbi: None. J. Klubo-Gwiezdzinska: None. Introduction: Primary thyroid lymphoma is an extremely rare thyroid malignancy accounting for less than 5% thyroid malignancies. The management depends on the histological subtype and tumor staging, typically involving chemotherapy alone or combined with radiotherapy. Although, surgical intervention is generally not recommended, given the potential surgical risks and the absence of additional benefits compared to chemoradiation therapy, it is reserved to obtain tissue diagnosis and to treat compressive symptoms. Clinical Case: A 66-year-old Caucasian female presented with dysphagia to solid food and acute neck swelling for a few weeks. History was negative for fever, weight loss or nocturnal diaphoresis. The patient had a history of primary hypertension, pre-diabetes, and Hashimoto’s hypothyroidism. A neck computed tomography (CT) scan showed a thyromegaly (8.3 x 5.8 cm) and bilateral cervical lymphadenopathy. Thyroid ultrasound showed sub centimeter nodules in the right mid-gland and a heterogeneous and irregular left thyroid lobe. TSH was normal (0.87 mcIU/mL [0.27-4.2]). She was treated for suspected subacute thyroiditis with prednisone for two weeks, showing initial clinical improvement, but symptoms recurred after steroids were stopped. Subsequently, a CT neck and fludeoxyglucose F18 (FDG) positron emission tomography (PET) scan demonstrated FDG avid thyroid enlargement with local adenopathy and rightward tracheal deviation. Lymph node, FNA, core biopsies and molecular testing were consistent with stage IIE MYC/BCL6 rearranged diffuse large B-cell lymphoma as she had no bone marrow or central nervous system (CNS) involvement. The patient’s treatments included four cycles of etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab with ibrutinib added after the first cycle and intrathecal methotrexate with cycles 3-6, to reduce the risk of CNS involvement. A 6-month post-therapy follow-up showed complete response (CR) on imaging with symptoms resolution. Four months later, she experienced worsening symptoms, including dysphagia with solids and liquids, and hoarseness despite CR to therapy and stable CT imaging. Laryngoscopic evaluation noted left vocal cord paralysis and extrinsic compression of the tracheoesophageal groove. Patient opted for a left hemithyroidectomy, experiencing excellent symptom relief. Surgical pathology showed findings consistent with a necrotic tumor and residual areas of lymphocytic thyroiditis. No active DLBCL was appreciated. The patient remains in remission and continues to be symptoms-free 24 months post-thyroid lymphoma treatment. Conclusion: While thyroidectomy is not typically recommended as the initial treatment for primary thyroid lymphoma, it emerges as a potentially effective option to manage recurrent or persistent compression symptoms following the completion of medical therapy. Presentation: 6/3/2024