RESUMO
Carcinoma Ex-Pleomorphic Adenoma (CExPA) is a salivary gland carcinoma derived from a primary or recurrent benign pleomorphic adenoma (PA) extremely rare in minor salivary glands. In this paper, we report the case of a male afrodescendant patient, 37 years old, presenting a palatal irregular nodular lesion with approximately 3.5 cm diameter. The lesion had over two years of evolution, but started growing faster and presenting pain and ulceration in the last two months. The incisional biopsy revealed a typical pleomorphic adenoma with focal areas of nests of epidermoid and mucous cells, as well as microcyst formations, resembling the mucoepidermoid carcinoma (MEC). Immunohistochemical analysis revealed positivity for CK7, CK13, CK 14, p63 and Ki67 (about 30%), whereas α-SMA was restricted to the PA component. The diagnosis was CExPA (MEC-type). A discussion on the histopathological and immunohistochemical criteria for differential diagnosis of CExPA is provided in this work, hoping to contribute to a better knowledge and understanding of this rare malignant tumor. Key words:Salivary gland neoplasms, pleomorphic adenoma, adenocarcinoma, mucoepidermoid carcinoma, pathology, differential diagnosis.
RESUMO
Hyalinizing clear cell carcinoma (HCCC) is a rare malignant neoplasm that commonly arises in the palate, whose occurrence in other intraoral sites is extremely uncommon. We present a case of a 74 years old afro-descendant female presenting an asymptomatic swelling in the lingual region of teeth 32, 33 and 34, with four months of Evolution, promoting an area of bone resorption with imprecise margins. Incisional biopsy revealed proliferative nests of clear cells within a hyalinized fibrous connective tissue. Tumor cells showed immunohistochemical positivity for AE1/AE3, CK7, p63 and ki67 (30%), but negativity for CK14, CK19 and α-SMA. The final diagnosis was HCCC. The tumor was subjected to surgical resection and no recurrence was observed after 16 months. CCCH is a low-grade malignant tumor that must be differentiated from other malignant clear cell tumors, including epithelial-myoepithelial carcinoma, myoepithelial carcinoma, mucin-depleted mucoepidermoid carcinoma and metastatic renal clear cell carcinoma. Immunohistochemistry is a useful tool to achieve the correct diagnosis and provide the proper therapy for the tumor.