Myoepithelial carcinoma arising in recurrent pleomorphic adenoma in maxillary sinus

Abstract

Myoepithelial carcinoma is characterized by nearly exclusive myoepithelial differentiation and evidence of malignancy. It may arise de novo or in preexisting benign tumors including pleomorphic adenoma and benign myoepithelioma. A 39-year-old lady presented with painless progressive swelling on the right cheek and right side of palate. On surgery, there was a mass in right maxillary sinus which was surgically excised and diagnosed on histopathology as pleomorphic adenoma. Subsequently, there were two recurrences. The first recurrence was in the right maxilla after 2 years that was removed surgically and diagnosed as pleomorphic adenoma. One year later, she came with rapidly progressive swelling in bilateral cheeks and face. Intraoperatively, there was a large tumor in both maxillary sinuses with extensive local infiltration. Histologically, it was diagnosed as myoepithelial carcinoma. Carcinoma ex pleomorphic adenoma is usually a high grade malignancy. It occurs most commonly in parotid gland followed by submandibular glands, minor salivary glands and occasionally in sublingual gland. To the best of our knowledge, this is the first case of myoepithelial carcinoma arising in a recurrent pleomorphic adenoma in the maxillary sinus.

Pleomorphic adenoma in the nasal cavity: a clinicopathological study of ten cases in Finland

“…In this series the reported carcinoma ex pleomorphic adenoma patient was male and all the other three carcinoma patients in their literature review were females [8]. In the study by Toluie and Thompson [13] 80 % (12/15) of patients with malignant transformation were women and in the other two reports all the three patients were also women [12][13][14]. It seems that a clear gender difference exists among the reported patients with a carcinoma arising from pleomorphic adenoma.…”

“…In addition to their own case, three other cases with a malignancy ex sinonasal pleomorphic adenoma were found in the literature. Myoepithelial carcinomas arising in recurrent pleomorphic adenomas in the maxillary sinus have also been described and this case report was included in the above-mentioned review by Kuan et al [8,14].…”

“…Further, infrequent malignant transformations have been reported [7,8,[12][13][14]. Toluie and Thompson [13] reviewed a series of nine of their patients with sinonasal tract adenoid cystic carcinoma ex pleomorphic adenoma (between 1970 and 2000) and six patients from the literature (publications in English (MEDLINE 1966(MEDLINE -2012 [13].…”

Myoepithelioma of Parotid: A diagnostic dilemma

“…malignant myoepithelioma is also crucial as it has a more aggr essive clinical behaviour, may recur even after adequate treatment or metastasize. 8 Histopathologically, presence of cellular atypia, cellular pleomorphism, necrosis, increased mitotic figures and infiltrative growth pattern favour the diagnosis of malignant myoepithelioma. 2,5 Myoepitheliomas show variable results on immunostaining.…”

Sinonasal and skull base pleomorphic adenoma: a case series and literature review

“…Previous reports of primary PA originating from within the nasal cavity and paranasal sinuses have been limited to individual case reports or, at most, case series of several patients. An even fewer number of reports have been made of PA or related neoplasms of the skull base .…”