Comprehensive analysis of primary thyroid lymphoma: a case report and review of diagnostic and treatment protocols

Background: In clinical practice, primary thyroid lymphoma (PTL) is a rare malignant neoplasm, making up only 2-5% of all thyroid malignancies. The most common type of PTL is diffuse large B-cell lymphoma (DLBCL), which accounts for about 60-70% of thyroid lymphomas. Typically, patients present with a painless progressive growth of neck masses, accompanied by local compressive symptoms. Currently, accurate diagnosis and treatment selection for PTL are significantly challenging. Research on PTL involving the pyramidal lobe is relatively scarce, resulting in persistently high rates of misdiagnosis and missed diagnosis. Additionally, uncertainties remain regarding the optimal surgical resection range and chemotherapy dosage for such combined lesions. Case Description: Here, we report a case involving a 66-year-old woman with a 16-year history of hypothyroidism, who presented with typical compression symptoms. After surgical resection, the patient was diagnosed with DLBCL of the right thyroid and pyramidal lobe, based on pathology and then underwent rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy. Following treatment, there was no recurrence or metastasis observed during the 6-month follow-up period. Conclusions: This case proves that the incidence of pyramidal lobe lymphoma involvement in PTL is extremely low and prone to missed diagnosis. Perioperatively, we should strengthen the awareness of this issue to reduce the possibility of misdiagnosis and missed diagnosis. Meanwhile, with a clear pathological diagnosis, a reasonable and effective chemotherapy regimen can achieve excellent therapeutic effects. Local symptoms can also be effectively alleviated through surgical resection.