Synchronous cervical lymph node involvement with a papillary thyroid carcinoma and small lymphocytic lymphoma: a case report

The occurrence of multiple malignancies in the same lymph node is rare, and even more so when these malignancies include both papillary thyroid carcinoma (PTC) metastasis and small lymphocytic lymphoma (SLL). We present a unique case of a 58-year-old male with a history of stable, indolent SLL, who developed metastatic PTC within a lymph node previously involved by lymphoma. Despite initial treatment with total thyroidectomy and cervical lymphadenectomy, post-operative surveillance showed elevated thyroglobulin levels and suspicious lymphadenopathy, prompting further investigation. Fine needle aspiration of the lymph node revealed SLL, but the thyroglobulin level in the aspirate was elevated, suggesting metastasis. A subsequent lymph node dissection confirmed PTC metastasis within the lymphomatous background. This case emphasizes the diagnostic challenges in patients with multiple malignancies, particularly when the presence of an indolent lymphoma complicates the assessment of lymphadenopathy.