Fig. 2

Corresponding contrast-CT, PET-CT and post-RCT neck specimen. Corresponding axial contrast-CT (a), PET-CT (b) and hematoxylin and eosin stained histopathology of ND specimen (c) of a 32-year-old male patient with oral HNSCC, initially staged cT2 cN2b cM0. While both, contrast-CT- and PET-CT-report found no persistent neck disease, post-RCT ND revealed vital tumor cells in 3 of 48 lymph nodes, all of which showed extracapsular spread. The index LN, which was classified negative for persistent neck disease (a, b) and the site of extracapsular spread in the post-radiotherapy ND specimen (c) are indicated with black arrows. For the index LN, the maximum short axis diameter was 1.6 mm and the maximum SUV 2.4. Despite post-RCT ND, the patient developed further tumor recurrences and died 6 months after treatment