Lymphoepithelial Carcinoma—Review of the Treatment Modalities and Report of a Rare Case in the Sublingual Gland

Malignant sublingual gland tumors: A single-center retrospective analysis of 79 patients

OBJECTIVES

To analyze and summarize the clinicopathological features, risk factors for cervical nodal metastasis, and prognostic factors of malignant sublingual gland tumors (MSLGT).

METHODS

Patients diagnosed with MSLGT were retrospectively reviewed from January 2005 to December 2017 at Shanghai Ninth Hospital. The clinicopathological features were summarized, and the correlations between clinicopathological parameters, cervical nodal metastasis, and local-regional recurrence were evaluated using the Chi-square test. Kaplan-Meier method and Cox regression analysis were performed to assess the survival and independent prognostic factors.

RESULTS

Seventy-nine patients were included, and the 5-year overall survival and disease-free survival rates was 85.7% and 71.7%, respectively. Gender and clinical tumor stage were risk factors for cervical nodal metastasis. Tumor size and pathological lymph node (LN) stage were independent prognostic factors for adenoid cystic carcinoma (ACC) of the sublingual gland; while age, pathological LN stage, and distant metastasis were prognostic factors for patients with non-ACC of the sublingual gland. Patients with higher clinical stage were more likely to undergo tumor recurrence.

CONCLUSIONS

Malignant sublingual gland tumors are rare, and neck dissection should be performed in male MSLGT patients with higher clinical stage. Among patients with both ACC and non-ACC MSLGT patients, pN+ indicate a poor prognosis.

Lymphoepithelial Carcinoma of the Sublingual Gland: A Case Report

Lymphoepithelial carcinoma (LEC) of the salivary gland is a rare squamous cell carcinoma. LEC commonly presents in the parotid and submandibular glands and rarely in the sublingual gland. While salivary gland LEC has a predilection for Inuit-Yupik and Chinese populations, few cases have been reported in the Hispanic population and none for sublingual glands in the English language literature. Here, we present the seventh case report in the English language literature for sublingual LEC and the first case observed in a Hispanic patient.

Uncommon Sites of Lymphoepithelial Carcinoma in Head and Neck Region

We present two cases of Lymphoepithelial carcinoma (LEC) which were found in uncommon sites, the first at the right parotid salivary gland and the second at the base of the tongue. Both patients presented with painless neck masses and were diagnosed with histologic analysis. There is an association with Epstein-Barr virus (EBV) infection in the first case, but none was found in the second case. The primary and metastatic LEC are indistinguishable through histological studies. Therefore, examination of nasopharynx and neck imaging is vital to differentiate primary and metastatic LEC in non-nasopharyngeal sites. A collaboration between surgeons and pathologists is essential for accurate diagnosis of LEC. Radiotherapy is the main choice of treatment for LEC, similar to the cases in the nasopharynx.

Lymphoepithelial carcinoma in the sublingual gland

Lymphoepithelial carcinoma is rare in the salivary glands, with an incidence of 0.4%. The most commonly affected site is the parotid gland, followed by the submandibular gland. Lymphoepithelial carcinoma in the sublingual gland has been reported only four times in the existing English-language literature. Such tumours are characterized by the presence of a poorly differentiated carcinoma that is surrounded and infiltrated by lymphocytes, and they are strongly associated with Epstein-Barr virus infection, patient ethnicity, and prominent radiosensitivity. Wide surgical excision combined with adjuvant therapy has been suggested as the first-choice therapeutic regimen. This report describes the case of a 34-year-old Indonesian woman who was evaluated and treated in Taipei Medical University Hospital. She had a tumour that presented as a painless swelling on the floor of the mouth. The diagnosis was confirmed by conducting an incisional biopsy, and a wide surgical excision with bilateral supraomohyoid neck dissection and free flap reconstruction was performed. The patient also underwent adjuvant chemoradiotherapy. No evidence of local recurrence or distant metastasis was detected during the 6 months of follow-up. Subsequently, the patient returned to her home country, and further follow-ups were not conducted.

NUT Midline Carcinoma of the Sublingual Gland: Clinical Presentation and Review

NUT midline carcinoma (NMC) is a rare and aggressive disease encountered in the midline of the head and neck or mediastinum. Due to its sparse incidence and subtle pathologic features, we aim to increase knowledge and awareness for this pathologic entity. We present an exemplary case of a young, healthy male presenting with oral cavity pain and cervical lymphadenopathy. This patient was initially diagnosed with an unspecified, highly aggressive sublingual gland malignancy and underwent locoregional resection with free flap reconstruction however suffered a rapid local recurrence and widely extensive metastasis within just 1 month. After rigorous analysis, final pathologic diagnosis revealed a poorly differentiated carcinoma with evidence of squamous differentiation that eventually, post-mortem tested positive for NMC. Only one prior case of sublingual gland NMC has been previously reported as we discuss the literature regarding all sublingual gland malignancies as well as the pathologic features and treatment options for NMC. We recommend consideration of testing for the NUT proto-oncogene at the time of biopsy in the clinical setting of a poorly differentiated midline carcinoma, especially with squamous differentiation, of the head or neck in order to identify patients for clinical trial enrollment and appropriately counsel on the poor clinical prognosis. Improving clinician awareness is critical to increase diagnostic accuracy and need to study prospective treatment outcomes as the first step toward improving management of this difficult disease.