Carcinoma Ex Pleomorphic Adenoma of the Palate Composed of Invasive Micropapillary Salivary Duct Carcinoma and Adenoid Cystic Carcinoma Components

Abstract

Carcinoma ex pleomorphic adenoma (CXPA) is an unusual epithelial malignancy that develops from a primary or recurrent pleomorphic adenoma (PA), the most common tumor of salivary glands, and constitutes about 11.5% of all carcinomas that affect these glands. Intraoral minor salivary glands and seromucous glands of the oropharynx are uncommon locations of CXPA. On histopathological examination, the tumor comprises a wide morphological spectrum with a variable proportion between the benign and malignant components with the latter often predominating and overlapping the PA, which may cause misdiagnosis. Here, we report a case of palatal minor salivary gland CXPA composed of invasive micropapillary salivary duct carcinoma and adenoid cystic carcinoma components with multiple nodal metastases in a 74-year-old woman. Neoplastic cells showed heterogeneous immunohistochemical profile with both luminal and myoepithelial differentiation. The invasive micropapillary salivary duct carcinoma component demonstrated overexpression of the oncoprotein human epidermal growth factor receptor-2. This feature should be considered and evaluated as a possible target for adjuvant therapy in case of metastatic disease.

Pedunculated carcinoma ex pleomorphic adenoma of the nasal cavity

“…In the present case, we identified both undifferentiated and squamous carcinomatous components in the surgical specimen. CXPAs with double differentiation of the carcinomatous component have also been reported in minor salivary gland CXPAs arising from the palate [7] and buccal mucosa. [29] However, the relevance of this histopathological feature remains unclear.…”

Pleomorphic Adenoma of the Upper Lip: A Rare Presentation in a Young Boy and Differential Diagnosis

“…This subset of tumour mainly arises from major salivary glands, mostly parotid, followed by submandibular glands (Antony et al, 2012). Nevertheless, these occurrences of malignant transformation were reported in PA arising from minor salivary glands mostly on the hard and soft palate (Yoshihara et al, 1995;Damm and Fantasia, 2001) and around 10.5% affects the upper lip (Ellis and Auclair, 2008;Mitate et al, 2013;Sedassari et al, 2014). Due to the long-standing nature of the transformation, it is rarely encountered in children (Lack and Upton, 1988) and more commonly seen in patients in the sixth and seventh decade of life (Olsen and Lewis, 2001).…”