Myoepithelial Carcinoma Arising in a Plasmacytoid Myoepithelioma of the Parotid Gland Synchronized with Melanoma: A Case Report and Review of the Literature

Abstract

Myoepithelial carcinoma, also known as malignant myoepithelioma, is considered an extremely rare (0.45–1%) malignant salivary gland neoplasm. Approximately 100 cases have been reported in the English-language literature on myoepithelial carcinoma. The majority of the myoepitheliomas described in the literature have been benign, and the malignant counterpart is considered rare (<1%). Such a tumor may appear de novo or rarely develop from a preexisting pleomorphic adenoma (<20%), and in exceedingly rare cases (<0.5%), it has arisen from a benign myoepithelioma (i.e., plasmacytoid myoepithelioma). To our knowledge, no case of myoepithelial carcinoma of the parotid gland arising in a plasmacytoid myoepithelioma synchronized with melanoma has been reported to date. The treatment of myoepithelial carcinoma has been mainly surgical, including wide excision with free margins, with or without nodal dissection. The roles of chemotherapy and radiotherapy have not yet been established. We report a case of myoepithelial carcinoma of the parotid gland arising in a plasmacytoid myoepithelioma synchronized with melanoma in a 40-year-old woman. In our case, a complete response was achieved with surgery followed by adjuvant chemotherapy based on carboplatin and paclitaxel concurrent with radiotherapy.

Myoepithelial Carcinoma of Soft Tissue

“…Currently, there is no standardized protocol for the treatment of myoepithelial carcinoma. The mainstay is wide excision or amputation, with or without nodal dissection 2,24 . However, recurrence rates are 40% to 45%, prompting the consideration of additional treatment options 14 .…”

Effects of Low Power Laser Radiation on Rat Submandibular Gland Tumors: Histopathological and Histomorphometric Studies

“…Los resultados histomorfométricos de este trabajo demostró a través del análisis estadístico de las medias, desviación estándar y mediana de ambos grupos estudiados que: los grupos control y experimental expresaron en todos los casos valores mayores en el grupo experimental siendo las diferencias estadísticamente significativas (p<0,0061) lo que está indicando que las RLBP indujeron de manera altamente significativa a la apoptosis de las células tumorales. El mismo autor propone en cuanto al tratamiento, la cirugía con amplios márgenes de seguridad como el más efectivo en el manejo de los carcinomas mioepiteliales Diferentes investigadores 19,20,21,22 afirman que en general el tratamiento de tumores de glándulas salivales es quirúrgico debiendo realizarse la recesión de alguna de ellas. La radioterapia constituye una importante alternativa terapéutica en circunstancias en que los márgenes quirúrgicos son positivos, cuando el grado de malignidad es elevado, cuando hay compromiso de algún nervio o se detectan ganglios positivos y también cuando puede producirse siembra del tumor durante la cirugía por ruptura de la cápsula.…”

Myoepithelioma of parotid gland: a case report

“…4 The recurrence rate of ME is described as 15-18%, with possible malignant transformation associated to long term cases or recurrences, which has been attributed to the overexpression of c kit receptors and mutation of the gene p-53. 1,2,10 Thus, even after complete excision of the lesion, follow-up of these patients for an extended period of time is recommended.…”