Papillary thyroid carcinoma in a patient with long‑standing chronic lymphocytic leukemia: A case report

The synchronous occurrence of papillary thyroid carcinoma (PTC) and chronic lymphocytic leukemia (CLL) is rare and poses diagnostic challenges, particularly in distinguishing metastatic thyroid disease from hematological lymphadenopathy. The present report documents the case of a 64‑year‑old female patient with long‑standing CLL who presented with a malignant thyroid nodule accompanied by multiple enlarged cervical lymph nodes. A diagnosis was established through integrated immunohistochemistry, flow cytometry and multimodal imaging. After the diagnosis of synchronous PTC and CLL/SLL was confirmed, the patient underwent a total thyroidectomy with central compartment lymph node dissection. In addition, a focused review of the literature was conducted to contextualize the clinical presentation, diagnostic strategies and management approaches. Treatment and follow‑up were guided by a multidisciplinary team. No adverse events occurred during follow‑up. At the latest follow‑up in November 2025, the patient remained clinically stable, with no evidence of PTC recurrence or CLL progression, and thyroid function test results showed decreased T3, elevated T4 and free T4, mildly elevated thyroid‑stimulating hormone, and free T3 within the reference range. The present case highlights the importance of a comprehensive diagnostic work‑up and provides practical guidance for the diagnostic and therapeutic management of patients with dual malignancies.