Some lateral cervical lymphadenopathies may lead to the discovery of papillary microcarcinomas (PMC) of the thyroid that are not radiologically apparent. This relatively rare clinical situation raises questions about the diagnostic approach to chronic cervical lymphadenopathy and the impact of lymph node metastasis on PMC prognosis.

To study the epidemiologic, clinical, and prognostic criteria of cases of lymphadenopathy that signaled PMC.

A retrospective study of 167 consecutive cases of PMC compared with 13 cases where a cervical mass signaled other forms of PMC.

The mean age was 48.5 years, the ratio of men to women was 5:8, and the mean PMC size was 5.5mm. These data did not differently significantly from those of the other PMC cases. The preoperative imaging found fluid content in six cases, with microcalcifications in three cases. All cases were treated by modified radical neck dissection on the side with the lymphadenopathy and total thyroidectomy with central neck dissection. The lymphadenopathy included a ruptured capsule in five cases and was accompanied by central lymph node metastases in three cases. Thyroid capsule involvement was significantly more common in cases of PMC discovered due to lymphadenopathy than in other cases of PMC (69% versus 9.7%, respectively; p<0.001). The mean follow-up was 7.3 years. There were no deaths due to PMC signaled by lymphadenopathy. Two cases of lymph node recurrence after 8 and 10 years were controlled by another surgery and radioactive iodine treatment.

Any chronic cervical mass should suggest the possibility of thyroid origin, especially in cases with cystic content or microcalcifications in subjects with no particular risk factors. An ultrasound of the thyroid should be done, as well as a fine needle aspiration biopsy of the lymphadenopathy with a thyroglobulin assay. Treatment is the same as for any thyroid carcinoma, and results in a good oncological outcome, despite the possibility of lymph node recurrences.