Pleomorphic adenoma: the great mimicker of malignancy.

Authors :: Hernandez-Prera JC
Skálová A
Franchi A
Rinaldo A
Vander Poorten V
Zbären P
Ferlito A
Wenig BM
Source :: Histopathology [Histopathology] 2021 Sep; Vol. 79 (3), pp. 279-290. Date of Electronic Publication: 2021 Apr 22.
Publication Year :: 2021
Abstract: Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and its diagnosis is straightforward in the majority of cases. However, not infrequently, PA shows unusual and uncommon histological features that can be confused with those of malignancy. The difficulties in diagnosing PA arise from its ability to mimic invasion, show atypical or metaplastic cytomorphology, and show morphological features that overlap with those of established salivary gland carcinomas. In addition, recognising early malignant transformation to carcinoma ex-pleomorphic adenoma continues to be a frequent challenge. This review describes the diagnostic pitfalls of PA, and offers a systematic approach to avoid them by combining classic histopathology with novel immunohistochemical and molecular tests.<br /> (© 2021 John Wiley & Sons Ltd.)