Ear, Nose & Throat Journal2023, Vol. 102(12) 762–764© The Author(s) 2022Article reuse guidelines:sagepub.com/journals-permissionsDOI: 10.1177/01455613221080074journals.sagepub.com/home/ear
Oncocytic carcinoma (OC) is a pretty rare malignant neoplasm. Oncocytic carcinomas mainly occur in major salivary glands but infrequently occur in minor salivary glands. We report a case of OC occurring in the retromolar glands involving the ipsilateral tonsil, which has not been reported in the English literature. This case may expand the database of OC, and provide diagnosis and treatment ideas for clinicians.
Keywordsoncocytic carcinoma, retromolar area, retromolar gland, tonsil
Oncocytic carcinoma (OC) of salivary glands is a kind of rare malignant epithelial tumor, which accounts for only .18% of all salivary gland carcinomas.1 The salivary gland-derived OC was first described by Baure in 1953,2 and was included for the first time in the World Health Organization (WHO)’s salivary gland tumor classification in 1991.3 Most cases occur in the parotid glands, and a small number of cases involve the submandibular glands, palatine glands, and labial glands.4-6 This article describes a rare case of OC in retromolar glands involving ipsilateral tonsil.
A 56-year-old Chinese female suffered from swelling and pain in the retromolar area for nearly a month. Physical examination showed a tough, irregular mass about 2*3 cm in size with telangiectasia on the surface. No dysfunction of the lingual nerve and inferior alveolar nerve was detected. No diseased lymph nodes were touched on both sides of the neck. Doppler ultrasound revealed a solid hypoechoic tumor under the base of the tongue. Computed tomography (CT) showed alveolar bone destruction in the left retromolar area (Figure 1). The patient presented an unremarkable medical history. The preoperative biopsy indicated the lesion was a malignant epithelial-derived tumor. Intraoperatively, we extendedly removed the tumor including part of the mandible and the ipsilateral tonsil. The sentinel lymph node biopsy showed no tumor cells in the lymph node; therefore, no neck dissection was carried out.
Histopathology revealed that carcinoma cells were arranged in alveolar nests, and infiltrated the surrounding glands (Figure 2A). The cells had abundant granular eosinophilic cytoplasm and vehicular nuclei with prominent nucleoli, some cells had binucleate or multinucleate, but mitotic phase was rare. Immunohistochemically, the carcinoma cells reacted positively for cytokeratin 7 (CK7) (Figure 2B), but negative for cytokeratin 5/6 (CK5/6), P63 protein, calponin, S-100 protein, human epidermal growth factor receptor 2 (HER-2), vimentin, and smooth muscle actin (SMA). The positive rate of ki-67 was 5-10%.
Previous acceptable criteria for diagnosis of OC include local lymph node metastases; distant metastases; frequent mitoses and cellular pleomorphism; and intravascular, perineural, or lymphatic invasion.7 In the latest WHO Classification of Head and Neck Tumors, OC is defined as a malignant epithelial neoplasm composed exclusively of neoplastic oxyphilic cells and does not display any histopathological features of other specific salivary gland tumor types.8 The differential diagnosis includes the oncocytic variant of mucoepidermoid carcinoma and salivary duct carcinoma.8 The former displays the features of typical mucous cells and the latter mimics OC but exhibits other patterns, especially comedonecrosis. In addition, it is also essential to identify OC from oncocytoma. Generally speaking, the rate of ki-67 positive cells is higher in OC in comparison with that in oncocytomas, except for the classic appearance of malignancy.9
In the present case, swelling and pain in the retromolar area were the initial symptoms. The lesion occurred in retromolar area and involved the ipsilateral tonsil. The bone destruction was found, indicating malignancy, although no obvious neurological symptom was complaint of or detected. Histopathological findings of large polyhedral cells with abundant granular eosinophilic cytoplasm and local invasion suggested the characteristics of OC. Intense positive CK7 staining indicated that the carcinoma cells are of epithelial origin. Therefore, the diagnosis of OC was made based on above features, though the positivity rate of ki-67 was 5-10%.
To our best knowledge, this is the first report of OC in the retromolar area. Because of the rarity of the disease, it is difficult to obtain sufficient data to develop guidelines for treatment. According to Goode and Corio’s theory, tumors larger than 2 cm seem to have a worse prognosis than those smaller ones.10 In this case, therefore, the patient was treated with enlarged resection, with partial mandibular resection and total ipsilateral tonsil excision. Neck dissection was not performed because no tumor cells were seen in the sentinel lymph node. The patient is undergoing postoperative radiotherapy for better prognosis, and is still under close follow-up.
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Not applicable
Qilin Liu https://orcid.org/0000-0002-9622-1881
1 Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Jilin University, Changchun, Jilin, China
2 Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, Jilin, China
Received: January 2, 2022; revised: January 19, 2022; accepted: January 24, 2022
Corresponding Author:Qilin Liu, Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Jilin University, Changchun, Jilin 130021, China.Email: qlliu@jlu.edu.cn
