Palisading adenocarcinoma is a morphologically distinct salivary gland neoplasm that has been recently described with predilection to the sublingual gland. We report our experience with this neoplasm to corroborate and enrich the literature and further clarify its phenotype.

BACKGROUND: Hyalinizing clear cell carcinoma (HCCC) of the salivary glands is a rare low-grade malignant tumor. This type of tumor is particularly uncommon in the sublingual glands.
METHODS: A 57-year-old female with a mass on the left side of the floor of the mouth that had been present for 2 months. The computed tomography scan of the neck revealed a nodular abnormal density shadow in the left sublingual area, measuring approximately 2.6 cm × 1.9 cm.
METHODS: Primary HCCC of the sublingual gland.
METHODS: The patient underwent surgical treatment and reconstruction using a left anterolateral femoral free flap, which showed immunohistochemical positivity for CK 5/6, CK 7, CK (AE1/AE3), and Ki-67 (<5%), but negative for SMA and S-100.
RESULTS: No recurrence was observed during the 12-month postoperative follow-up period.
CONCLUSIONS: The absence of characteristic clinical manifestations makes HCCC highly susceptible to misdiagnoses. This case presents a rare instance of HCCC in the sublingual gland, providing a reference for the clinical diagnosis and treatment of the disease.

Ranula is a mucous cyst that occurs in the sublingual gland (SLG) in the floor of the mouth. It can be classified into two types based on origins: One is the the lesser sublingual gland (LSLG) in the anterior segment and the Rivini duct, which is connected to it, and the other is the greater sublingual gland (GSLG) in the posterior segment. Because of the anatomical characteristics, surgical resection of the cysts carries the risk of damaging adjacent tissues and has a high recurrence rate. Intralesional injection of sclerotherapy may be a better alternative treatment. We summarized 65 cases of ranula treated with intralesional injections of bleomycin(BML). According to the origin of the ranula, 60 cases were from the LSLG and the Rivini duct, and 5 cases were from the GSLG. The results showed that 60 cases of ranula from LSLG and Rivini ducts were 100% cured during the follow-up period. The median number of injections for all patients was 1.16. All 5 cases of ranula from the GSLG did not wholly recover. This study confirmed that BLM intralesional injection is a safe and effective treatment modality for cysts from LSLG or the ducts of Rivini rather than GSLG. Therefore, before treatment, it is necessary to determine the type and origin of the cyst by characterizing its morphology to ensure the effectiveness of the treatment.

Adenoid cystic carcinoma (AdCC) is a malignant salivary gland neoplasm that presents as an indolent but aggressive neoplasm. AdCC histogenesis is linked to the intercalated ducts of the salivary glands, equally affecting the major and minor glands. AdCC is associated with distant metastasis, most commonly to the lungs, and a high recurrence rate. AdCC accounts for 4.2% of all tumors. About 55% of all reported cases affect the submandibular gland, and around 50% of AdCC cases occur in the minor salivary glands. The present review describes a case of AdCC which presented a single nodular swelling on the right side involving the floor of the mouth. It also consolidates the histopathological profile of a case of AdCC with all the relevant histopathological features.

Adenoid cystic carcinoma is a rare malignant tumor that primarily occurs in the salivary glands. There are few reports of sublingual gland adenoid cystic carcinoma with lung metastases on which 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) was performed. We report the case of a 57-year-old Japanese woman with an adenoid cystic carcinoma of the sublingual gland with lung metastases in whom the FDG uptake of the lung metastasis was low despite high FDG uptake in the primary lesion. The pathological examination revealed that solid components were more visible and the Ki-67 index was more positive in the primary lesion compared to the metastatic lesion. We speculate that differences in tumor growth ability might have resulted in the differences in FDG uptake. This case demonstrates that significant differences might occur in the FDG uptake between primary and metastatic tumors.

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.

Saliva is vital to oral health, fulfilling multiple functions in the oral cavity. Three pairs of major salivary glands and hundreds of minor salivary glands contribute to saliva production. The secretory acinar cells within these glands include two distinct populations. Serous acinar cells secrete a watery saliva containing enzymes, while mucous acinar cells secrete a more viscous fluid containing highly glycosylated mucins. Despite their shared developmental origins, the parotid gland (PG) is comprised of only serous acinar cells, while the sublingual gland (SLG) contains predominantly mucous acinar cells. The instructive signals that govern the identity of serous versus mucous acinar cell phenotypes are not yet known. The homeobox transcription factor Nkx2.3 is uniquely expressed in the SLG. Disruption of the Nkx2.3 gene was reported to delay the maturation of SLG mucous acinar cells. To examine whether Nkx2.3 plays a role in directing the mucous cell phenotype, we analyzed SLG from Nkx2.3-/- mice using RNAseq, immunostaining and proteomic analysis of saliva. Our results indicate that Nkx2.3, most likely in concert with other transcription factors uniquely expressed in the SLG, is a key regulator of the molecular program that specifies the identity of mucous acinar cells.

OBJECTIVE: The objective was to investigate the details of the attachments of the mylohyoid muscle to the mandible anterior to the hyoid and mylohyoid lines to understand the positional relationship between the sublingual space and the mylohyoid, knowledge that is essential for dental implant surgery in the incisal region, as well as the routes of communication between the sublingual space and other spaces.
METHODS: While evaluating the presence or absence of an anterior mylohyoid muscle fiber attachment to the mandible, sublingual gland herniation, spaces between muscle fascicles were also recorded as sites of penetration. The mean muscle thickness in each of these areas was also calculated.
RESULTS: In all specimens, the mylohyoid originated not only from the mylohyoid line but also from the lingual surface of the center of the mandibular body (the mandibular symphysis) below the mental spines. The mylohyoid muscle fascicles were thickest in the posterior region, and further anterior to this, they tended to become thinner. Sublingual gland herniations passing through the mylohyoid were noted in the anterior and central regions, but not in the posterior region. Penetration between the muscle fascicles was most common in the central region, and no such penetration was evident in the posterior region.
CONCLUSIONS: These results suggest that the mylohyoid functions only incompletely as a septum, and that routes of communication from the sublingual space to the submandibular space may be present in both the anterior and central muscle fascicles of the mylohyoid. Therefore, bleeding complications during dental implant placement in the anterior mandible can be serious issues. There is a potential for sublingual hematoma that could compromise the airway by pressing the tongue against the soft palate into the pharynx.

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.

Plunging ranula, a subtype of ranula, commonly presents as a submandibular or submental cystic mass without oral counterpart, and its clinical management remains challenging. Herein, the authors report an extremely rare case of 30-year-old female patient with plunging ranula involving the root of the left anterior neck.