Pleomorphes Adenom

pleomorphic

adenoma of parotid (cytology confirmed) in ultrasound

Imaging of

parotid anomalies in infants and children. Pleomorphic adenoma or mixed tumor. Axial T2-weighted image showing the hypointense capsule well delineating the tumor (a). At a different slice level, axial T1-weighted image (b), diffusion weighted image (c) and apparent diffusion coefficient map (d) showing a homogeneous tumor with a very high apparent diffusion coefficient

insightsimaging.springeropen.com • CC-by-4.0

Imaging of

the sublingual and submandibular spaces. Pleomorphic adenoma of the submandibular gland. a Axial and b coronal contrast-enhanced CT images demonstrate an enhancing well-circumscribed round mass within the inferior aspect of the right submandibular gland (arrow)

insightsimaging.springeropen.com • Open Access

RETRACTED

ARTICLE: The diagnostic value of combined dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) in characterization of parotid gland tumors. Male patient, 62 years old presented with large Rt. Parotid swelling. a Axial T2 WI and b coronal T2 fat sat MRI showed large well-defined mass of high SI involving superficial and deep lobes of the Rt. parotid gland. It shows medial displacement of the Rt. parapharyngeal space. It is seen compressing and medially displacing the right CCA. The mass is seen contacting the right ramus of the mandible anteriorly and the right sternomastoid muscle posteriorly. c Coronal post contrast T1 fat sat MRI showed heterogeneous enhancement of the mass with cystic areas inside. d DWI the lesion appeared hypointense. e ADC map with mean ADC value = 2.2 × 10−3 mm2/s. f TIC showing type A curve (TTP = 140 s). Pathological diagnosis: pleomorphic adenoma

ejrnm.springeropen.com • CC-by-4.0

Orbital mass

• Pleomorphic adenoma of the lacrimal gland - Ganzer Fall bei Radiopaedia

Gaillard, F. Pleomorphic adenoma of the lacrimal gland. Case study, Radiopaedia.org. (accessed on 21 Oct 2022) https://doi.org/10.53347/rID-9064 • CC by-nc-sa 3.0 (modified)

Pleomorphic

adenoma • Pleomorphic adenoma - parapharyngeal - Ganzer Fall bei Radiopaedia

Morgan, M. Pleomorphic adenoma - parapharyngeal. Case study, Radiopaedia.org. (accessed on 21 Oct 2022) https://doi.org/10.53347/rID-92075 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

Pleomorphic adenomas, also known by the misnomer benign mixed tumors (BMTs), are benign epithelial neoplasms related to glandular tissue. They have a small but real risk of malignant transformation.

For a discussion of specific sites of pleomorphic adenoma, please refer to

Terminology

Historically pleomorphic adenomas have also been called benign mixed tumors, however this name is now discouraged. It was previously thought that these were a form of teratoma, however it is now clear that the neoplasm forms from a single layer of germ cells and is purely epithelial in nature .

Pathology

Location

Pleomorphic adenoma most commonly occurs in salivary glands (especially parotid gland) but can arise in any tissue that has glandular myoepithelial tissue. Other reported sites include lacrimal glands, external auditory canal, skin, breast, and vulva .

Microscopic appearance

These tumors characteristically have a mix of epithelial and mesenchymal tissues . There is a spectrum of histological appearances (thus the term pleomorphic) but commonly includes ductal epithelium, myoepithelial cells, and myxoid stroma.

Treatment and prognosis

A large pleomorphic adenoma can be disfiguring or exert mass effect on important structures. More importantly, they have a proven risk (5-15%) of undergoing malignant transformation (carcinoma ex pleomorphic adenoma, or malignant mixed tumor) . Thus, complete surgical resection is the treatment of choice.

Local recurrent pleomorphic adenoma (RPA) occurs in a small proportion (<5%), up to 20 years after excision .