Endocrine Abstracts

Introduction: Occult papillary carcinomas are small thyroid carcinomas (<1 cm) diagnosed after an initial manifestation of lymph nodes or distant metastasis. We report two cases of patients with this pattern of clinical presentation.

Case description: The first case is a 21-year-old woman, with a one-year history of a growing cervical cyst. Fine needle aspiration of the cyst showed metastasis from papillary thyroid cancer. She had no previous history for thyroid pathologies. A thyroid ultrasound was performed and the gland was described as heterogeneous, with no clear evidence of a primary carcinoma site but with too highly hypoechoic areas in the left lobe. Initial blood tests were as follow: TSH, Thyroglobulin and Calcitonin within the normal range, high levels of anti-TPO and anti-TG confirming the diagnose of Hashimoto thyroiditis. Total thyroidectomy and lymph node resection was recommended to the patient. The post-surgery biopsy confirmed multiple papillary focal lesions of papillary carcinoma with maximal diameter 1 cm. The patient received 131-iodine therapy with 100 mCi and is on regular follow up. The second patient is a 45-year-old man, with no medical history who went to the general practitioner for a neck lump. After initial examination, a biopsy of the lymph node was recommended. The result revealed lymph node metastases probable from thyroid papillary carcinoma. Blood test were within normal range. Thyroglobulin 13.54 ng/ml (3.5-77). The patient underwent total thyroidectomy and bilateral neck dissection. Histopathological exam was consistent with a papillary carcinoma of 3 mm in size. Post-surgery thyroglobulin 8.02 ng/ml. In a couple of weeks, the neck lumps reappeared. A computerised tomography was performed and bilateral neck and axillary lymph nodes were observed. The patient underwent a second surgery and later, radioactive iodine therapy with 100 mCi. The second biopsy confirmed once again metastasis from thyroid papillary cancer. Post-second surgery Thyroglobulin 0.01 ng/ml. The patient is still under strict observation because of the recidivist lymphatic disease.

Conclusion: It is important to consider the diagnosis of papillary thyroid carcinoma in every patient that seeks medical evaluation for lymph node swelling. Despite the improvement of ultrasonography, many cases of occult papillary carcinoma remain undetected, emphasizing the role of pathological examination to confirm the diagnosis. The preferred treatment approach remains total thyroidectomy with ipsilateral cervical lymph node resection, usually followed by 131-iodine therapy. Key words: occult carcinoma, cervical lymph node, thyroglobulin, thyroidectomy, biopsy