FIGURE 3.  Algorithm for evaluation of unknown primary malignancy with cervical lymph node metastases. ^*Ipsilateral base of tongue, tonsillar fossa (TF), nasopharynx, and, in some cases, pyriform sinus and other TF. ⁺PET/CT may be helpful in this setting for detecting distant metastatic disease, additional regional lymph nodes with metastatic disease, and synchronous tumors. Bx+ = biopsy positive; Bx– = biopsy negative; FNA = fine-needle aspiration.