Co-expression of Myoepithelial and Melanocytic Features in Carcinoma Ex Pleomorphic Adenoma

Costantino Ricci,Maria Pia Foschini,Ottavio Piccin,Tiziana Balbi,Francesca Ambrosi,Ernesto Pasquini,Barbara Corti,Federico Chiarucci

doi:10.1007/s12105-021-01299-4

Costantino Ricci, Maria Pia Foschini + Show 6 more

Open Access

https://doi.org/10.1007/s12105-021-01299-4

Copy DOI

Abstract

The presence of melanin pigment and melanocytic markers expression have been rarely reported in salivary gland tumors. Herein, two cases of carcinoma arising in pleomorphic adenoma of the parotid gland and showing diffuse expression of myoepithelial and melanocytic markers are described. The clinical-pathological clues useful in the differential diagnosis with melanoma are discussed. In addition, a review of the pertinent literature is also proposed, discussing the pathologic mechanisms potentially involved in this phenomenon.

Highlights

Multi-lineage differentiation can be observed in salivary glands carcinomas, especially in myoepithelial cell carcinoma [1]
Case#1 In April 2020, a 77-years-old man was referred to our institution for a PET-FDG documented a hyperaccumulation in the right parotid gland (SUVmax = 29), highly suspicious for malignancy
The carcinomatous component gradually merged with the pleomorphic adenoma (PA) and the PA’s capsule was diffusely infiltrated

Summary

Introduction

Multi-lineage differentiation can be observed in salivary glands carcinomas, especially in myoepithelial cell carcinoma [1]. Based on melanoma history and the immunohistochemical features of the salivary gland lesion, a diagnosis of “suspicious for MM metastasis” was rendered, and the. In August 2015, a 63-years-old man underwent radiological work-up for the rapid onset of a left parotid gland swelling with facial nerve palsy. CT scan showed a 22 × 19 mm nodular lesion of the left parotid gland with infiltration of the facial nerve and suspicious for carcinoma; besides, multiple nodular lesions, radiologically suspicious for metastasis, were detected in the liver and both lungs. At 4 months follow-up, a CT scan showed a size increase of the lungs and liver lesions; repeated second dermatologic examination did not reveal skin melanoma. The patient died of widespread metastatic disease seven months later

Pathologic Findings

Discussion

Conclusions