Correlation between MRI (DWI and DCE) and cellularity of parotid gland pleomorphic adenomas

• Published in: European archives of oto-rhino-laryngology Vol. 281; no. 5; pp. 2655 - 2665
• Main Authors: Monestier, Laura, Del Grande, Jean, Haddad, Ralph, Santini, Laure, Michel, Justin, Varoquaux, Arthur, Fakhry, Nicolas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2024
• Subjects: Head and Neck; Head and Neck Surgery; Medicine; Medicine & Public Health; Neurosurgery; Otorhinolaryngology; Recurrence; Histological subtype; Parotid; MRI; Pleomorphic adenoma
• ISSN: 0937-4477; 1434-4726
• DOI: 10.1007/s00405-024-08562-8

Purpose
Parotid pleomorphic adenomas present a risk of recurrence, higher when the tumour is a hypocellular subtype. The aim of the study was to determine whether it is possible to characterize this histological subtype with diffusion and perfusion sequences of the preoperative MRI.
Methods
This retrospective study included 97 patients operated between 2010 and 2020. Histologic slides review was performed to classify tumours into three histologic subtypes: hypocellular, classical and hypercellular. Univariate and multivariate analyses studied the correlation between histology and diffusion and perfusion MRI parameters obtained with OleaSphere® software.
Results
The hypocellular subtype had higher apparent diffusion coefficient values than the other two subtypes: 2.13 ± 0.23, 1.83 ± 0.42, and 1.61 ± 0.4 × 10
–3
 mm
2
/s for hypocellular, classical and hypercellular subtype respectively (
p
 < 0.0001). Multivariate analysis showed that an ADC
mean
> 1.88 × 10
–3
 mm
2
/s was suggestive of a hypocellular pleomorphic adenoma in 79% of the cases, with a specificity and PPV of 94 and 96% (
p
 < 0.001), respectively.
Conclusion
The histological subtype of a pleomorphic adenoma can be predicted preoperatively with ADC values. A prospective and multicentric study on a larger cohort is needed to confirm our results.