Core classification of head and neck squamous cell carcinomas: correlations between morphology, DNA ploidy and HPV infection

Abstract

Aims: The study intended to reveal whether HPV infection is reflected by nuclear morphology and DNA cytometry parameters in head and neck squamous cell carcinomas (HNSCC).

Methods: In total, 39 HNSCC were selected for reanalysis by histomorphology applying the core classification, DNA cytometry and HPV detection. For the core classification, HE sections were assessed by a score system to evaluate the nuclear size, the mitosis size, their variabilities and the presence of tripolar or tetrapolar mitoses. HPV was analyzed by consensus PCR followed by a hybridization method for virus typing. Static DNA cytometry was applied on single cell suspension focusing particularly on the parameters DNA modal value, DNA index peak, DNA index mean, 2c deviation index and 5c exceeding rate. Statistical analysis was done by T-test or Fisher's exact test.

Results: The analysis revealed that HPV positive HNSCC had significantly smaller nuclei than HPV negative cases. Increasing values of the nuclear size and mitosis size were significantly associated with higher indices of the DNA cytometry analysis.

Conclusions: The study confirms that the core classification can provide information on the ploidy of HNSCC and that HPV positive tumors represent a distinct morphological and genetic carcinoma subtype.