Nasopharyngeal Soft Tissue Fullness

FDG-avid nasopharyngeal soft tissue fullness is not an uncommon finding, and is usually inflammatory in nature.

• If the soft tissue fullness is mild, midline, posterior and symmetric, it is typically inflammatory in nature – even if intensely avid.  In these cases, we generally report:
  • “While a neoplastic process cannot be entirely excluded, this is typically physiologic or inflammatory in nature.” 
• If FDG-avid nasopharyngeal soft tissue density is prominent, eccentric or mass-like in CT appearance, we must raise a suspicion for malignancy. In such cases, we generally report:
  • Ill-defined and intensely avid soft tissue density is noted to involve the left aspect of the nasopharynx, measuring up to 1.8 x 1.2 cm (SUV 4.1). While this can be inflammatory in nature, direct visualization is recommended to exclude a neoplastic process.”
• Caveat: The presence of associated hypermetabolic cervical nodes dramatically increases the likelihood of malignancy (and the confidence of your reporting). 
• Lateral Pharyngeal Recess: Intense uptake in the lateral pharyngeal recess (bilateral or unilateral), without an accompanying soft tissue density, is typically inflammatory.
• Longus Colli Muscles: Uptake within the longus colli muscles (unilateral or bilateral) reflects normal “muscle activation/strain” and should not be mistaken for malignancy.