A retrospective multicenter study of sublingual gland carcinoma in Japan

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.

Prognostic factors for sublingual gland carcinoma: a population-based Surveillance, Epidemiology and End Results database study

OBJECTIVE

To identify the clinical features and prognostic factors for sublingual gland carcinoma.

METHODS

This was a case-control study. Patients with surgically treated sublingual gland carcinoma were retrospectively included in the Surveillance, Epidemiology and End Results database and divided into adenoid cystic carcinoma (ACC) and non-ACC groups. Primary outcome variables were disease-specific survival (DSS) and overall survival (OS). Prognostic factors for each group were analyzed using Cox models.

RESULTS

We included 251 patients (115 men and 136 women). Compared with the non-ACC group, the ACC group had a larger average tumor size and received more adjuvant radiotherapy. In patients with ACC, the pathologic grade had an independent impact on DSS and OS, and patients who were undergoing adjuvant chemotherapy had worse DSS than those who were not receiving chemotherapy. In the non-ACC group, pathologic grade IV, lymph node metastasis, and adjuvant chemotherapy were associated with poor DSS and OS, and tumor extension predicted worsening DSS.

CONCLUSIONS

In sublingual gland carcinoma, the pathologic grade and adjuvant chemotherapy were the most important prognostic factors, whereas lymph node metastasis had a negative impact in non-ACC patients but not in ACC patients.

A torus-like sublingual adenoid cystic carcinoma in a 35-year-old male: Review of literature and case report

Key Clinical Message

The case report describes an adenoid cystic carcinoma occurring at a rare location and the diagnostic pathway. Swellings of the floor of the mouth, whether painful or without subjective symptoms and regardless of consistency, should be taken seriously.

Abstract

Adenoid cystic carcinoma (ADCC) of the sublingual salivary gland only accounts for 2% of all ADCCs. In this study, we report a rare case of ADCC with sublingual salivary gland origin in a 35-year-old man and a comprehensive review of articles published over the past 62 years.

Adenoid cystic carcinoma of the sublingual gland developing lung metastasis 20 years after primary treatment: A case report and literature review

RATIONALE

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that primarily occurs in the salivary glands. Distant metastases can develop despite favorable local control. Moreover, distant metastasis of ACC can occur after a long time interval without local recurrence. We report the first case of ACC of the sublingual gland that developed lung metastasis 20 years after primary treatment.

PATIENT CONCERNS

A 52-year-old man was referred to our department with a 1-year history of painful swelling on the right oral floor.

DIAGNOSIS

An incisional biopsy was performed, and histopathological examination revealed malignancy.

INTERVENTIONS

Surgical excision of the right oral floor and right supra-omohyoid neck dissection with postoperative chemoradiation therapy were performed, and ACC of the sublingual gland was diagnosed. Left pulmonary metastasis was detected 20 years after the primary treatment. Metastasectomy was performed; however, subsequently, skin and bone metastases developed.

OUTCOMES

After receiving palliative care, the patient died of multiple organ failure.

LESSONS

As late distant metastasis of salivary ACC can develop, patients who undergo primary treatment need a long-term, strict follow-up plan even if locoregional control is favorable.

Diagnosis and management of malignant sublingual gland tumors: a narrative review

OBJECTIVE

In this article we review the literature on the malignant sublingual gland tumors from a surgical perspective.

BACKGROUND

Sublingual gland tumors occur with a very low incidence and most are malignant tumors. The extent of treatment, clinical outcomes and prognosis of malignant sublingual gland tumors have not been well defined, due to the rarity of this disease.

METHODS

A database search using Web of Science (https://webofknowledge.com/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/) was conducted. The following keywords were used in the search: "sublingual gland tumor", AND "malignancy".

CONCLUSIONS

Although the sublingual glands are among the major salivary glands, they share common anatomical characteristics with minor salivary gland tumors. Therefore, the tumors from the sublingual gland may have different clinical behaviors from the other major salivary gland tumors. The sublingual glands are small without a true surrounding capsule of the glands; the extra-parenchymal extension is very common in sublingual gland tumors. Furthermore, the sublingual glands are located in close proximity to the lingual nerve, the submandibular gland-duct system and the mandible. Thus, the surgical approach to the malignant sublingual gland tumor should include the adequate management of neighboring structures. In addition, adjuvant radiation therapy provides a survival benefit for patients with malignant sublingual gland tumors, which have adverse features. This article summarizes the clinical characteristics and unique features of malignant sublingual gland tumors based on previous reports, and provides clinical information regarding the sublingual gland tumors to increase awareness of primary physicians as well as patients.

Analysis of local invasion and regional spread in malignant sublingual gland tumour: Implications for surgical planning

Malignant tumours arising from the sublingual glands are very rare, and the extent and frequency of local invasion or regional spread in malignant sublingual gland tumour (MSLT) has not been fully studied due to the disease rarity. To provide comprehensive features of local and regional spread of MSLT, we reviewed 20 surgical cases for detailed pathological analyses among 26 cases diagnosed as having primary MSLT. Adenoid cystic carcinoma (ACC) was the most common pathological subtype, followed by mucoepidermoid carcinoma. Disease-free and overall survivals at 5 years were 76.1 % and 77.7 %, respectively. High-grade malignant tumours and grade 2-3 ACC accounted for 41.7 % and 85.7 %. Clinical and pathological extraparenchymal extensions were found in 34.6 % and 80.0 %, respectively. Tumour invasion to the lingual nerve and submandibular gland/ductal system were also detected in 40.0 % and 28.6 %. The incidences of lingual nerve invasion in ACC and ACC ≥4 cm were 30.8 % and 42.9 %. Regional nodal involvement occurred in seven of 26 cases, and all metastatic lymph nodes were found in neck levels Ib and IIa. In summary, a significant portion of MSLT cases consisted of high-grade tumours and grade 2-3 ACC; therefore local invasion into adjacent structures should be cautiously evaluated in cases of MSLT.