Skip Metastasis in a Pediatric Patient with Medullary Thyroid Cancer: A Case Report and a Review of the Literature.

Skip metastasis in thyroid cancer occurs when there is lateral neck lymph node involvement of tumor without central neck lymph node involvement. Here, cancer spreads to the lateral neck while "skipping" more proximal central neck nodes. While this unusual pattern of spread has been previously described in adults with thyroid cancer, to our knowledge it has never been described in children. Here, we report a case of an adolescent female with medullary thyroid cancer with isolated lateral neck metastatic disease. In summary, a 15-year-old female with no medical conditions presented with an asymptomatic neck mass. A computed tomography (CT) scan of the neck showed a heterogenous nodule in the right thyroid lobe with both cystic and solid components which were also illustrated on ultrasound. There was no CT evidence of metastatic disease, but a thyroid and cervical neck ultrasound showed a <1 cm calcified nodule in right neck level II concerning for metastasis. Fine needle aspiration highlighted medullary thyroid cancer. The patient underwent total thyroidectomy with both central and right lateral neck dissection. Central neck dissection revealed no metastatic lymph nodes, while metastatic nodes were found with right lateral neck dissection, highlighting skip metastasis. The patient had an uneventful postoperative course and was well at 1-month follow-up with a strong voice and no dysphagia.