Upper retropharyngeal node involvement in differentiated thyroid carcinomademonstrated by I-131 scintigraphy

We report four patients with papillary thyroid cancer who had upper retroph aryngeal node involvement demonstrated by I-131 scintigraphy. Three patient s presented with a thyroid nodule and enlarged jugular nodes. Total thyroid ectomy was performed with node dissection. Pathology demonstrated papillary carcinoma with several metastatic nodes. I-131 scanning 4 weeks after surg ery demonstrated increased uptake in an upper retropharyngeal node. In one patient, thyroidectomy had been performed 21 years previously. Increased th yroglobulin level led to I-131 scanning, which showed focal retropharyngeal uptake. All four patients had asymmetrical uptake at mouth level with foca l uptake close to the sagittal plane. A lateral projection showed focal upt ake between the base of the skull and the mandibular angle, behind the regi on of the mouth and nose. CT in all cases and MRI in one case confirmed the presence of an enlarged node. The mass was removed surgically in two patie nts and pathology confirmed the papillary nature of the metastatic node. Tw o patients were treated by I-131. Focal uptake of I-131 in the region of th e mouth is ambiguous, since salivary uptake of I-131 is a common finding on scintigraphy. In cases of asymmetrical uptake in the region of the mouth, a lateral projection of the head therefore allows the correct diagnosis.