Elevated Thyroglobulin in Postoperative Follow-up of Metastatic Papillary Thyroid Carcinoma (PTC)

Clinical Presentation:
A 62-year-old male presented for postoperative follow-up after undergoing thyroid surgery in India in 2024 for papillary thyroid carcinoma (PTC), follicular variant, invasive, and non-encapsulated subtype. The pathology report had revealed two foci of the tumor, measuring 2.2 cm and 1.5 cm, with lymphovascular invasion. Additionally, three out of five lymph nodes examined showed metastasis with extranodal extension. The patient had a medical history of hypertension, for which he was on anti-hypertensive medication, and renal cell carcinoma. During the follow-up visit, his thyroglobulin level was found to be elevated, prompting further investigation to assess the possibility of recurrence or metastasis.

Laboratory and Imaging Investigations:
The laboratory investigations revealed significant findings that raised concerns for potential recurrence or metastasis. The Thyroid-Stimulating Hormone (TSH) level was found to be 75.9 uIU/mL, indicating hypothyroidism, which was likely due to inadequate thyroid hormone replacement following the initial thyroid surgery. The Free Thyroxine (FT4) level was 5.20 pmol/L, which was low, further supporting the need for adjustment of the thyroid hormone therapy regimen. Most notably, the Thyroglobulin (Tg) level was markedly elevated at >500 ng/mL, which is a key tumor marker for thyroid cancer and raised significant concerns for possible recurrent or metastatic disease, prompting further investigation and management.

The patient’s vocal cord assessment was normal bilaterally, indicating no evidence of vocal cord paralysis or dysfunction. Following the elevated thyroglobulin levels, the patient was referred for a thyroid ultrasound (US) to investigate further.

The ultrasound showed postoperative changes in both thyroid lobes, with edema and inhomogeneity, especially on the left side, which suggested the need for a re-evaluation once the patient's condition improved. On the right side, a few small lymph nodes were observed, with the largest being 11×3 mm in the right lateral neck (group III), but no suspicious features were seen. On the left side, the ultrasound revealed multiple small lymph nodes, with three large predominantly solid nodules or lymph nodes in the left lateral neck group III. These showed microcalcifications, highly suspicious for secondary lymph nodes originating from thyroid carcinoma. The largest of these nodes measured 32×24×11 mm.

Fine Needle Aspiration (FNA) and Diagnosis:
Due to the suspicious ultrasound findings, particularly in the left lateral neck, the patient underwent fine needle aspiration (FNA) of the lymph nodes. The cytology report confirmed metastatic papillary thyroid carcinoma (PTC), consistent with the patient's known diagnosis of thyroid cancer.

Surgical Procedure and Pathological Findings:
Based on the findings of metastatic lymph nodes, the patient was scheduled for left lateral neck dissection to remove the affected lymph nodes. During the procedure, 42 lymph nodes were dissected, and histopathological examination confirmed metastatic papillary thyroid carcinoma (PTC) in 11 of the 42 lymph nodes. These findings were consistent with the diagnosis of recurrent disease in the left cervical lymph nodes, and the patient was referred for further oncologic management, including consideration of adjuvant therapies like radioactive iodine or radiation therapy.

Head and Neck Surgeon: Prof. Dr. Abdulwahid Mohammed Salih
Co-surgeon: Dr. Yadgar Abdulhameed Saeed
Assistant: Dr Harun Amanj Ahmed