Diagnostic Difficulties of Plunging Ranula: A Review of 18 Cases

OBJECTIVE(S)

Despite advancements in imaging techniques and cytological analysis, plunging ranula remains a challenging surgical, radiologic, and pathologic phenomenon. Of the 18 patients we evaluated at our institution, we highlight three cases that illustrate the high rate of misleading imaging and cytological results when assessing plunging ranula.

METHODS

Imaging results, biopsy findings, operative techniques, and pathological reports were reviewed from patients who had either a preoperative or postoperative diagnosis of ranula and underwent surgery by a single head and neck surgeon at a tertiary care center.

RESULTS

Of the 18 identified patients, computed tomography was correct on preoperative imaging 73% of the time and magnetic resonance imaging was correct on preoperative imaging 71% of the time. Two patients underwent preoperative ultrasound and their ultrasound reports did not accurately diagnose the presence of a ranula. Two patients underwent preoperative fine needle aspiration biopsy due to inconclusive preoperative imaging, in which results suggested either a ranula or epidermal cyst. Both ultimately did not match the final pathology. Three of eighteen patients (17%) underwent an inappropriate initial surgery due to incorrect imaging diagnoses and/or biopsy findings.

CONCLUSION

Despite use of preoperative modalities to distinguish plunging ranula from other cystic floor of mouth lesions, surgeons must be aware that no workup modality is fully precise. The potential for revision surgery must be included in all preoperative discussions for presumed plunging ranula.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2689-2696, 2024.

Extraoral type of intraductal papilloma in sublingual gland: A case report

INTRODUCTION

It is rare for intraductal papilloma (IDP), a benign papillary tumor, to occur in the sublingual gland (SLG).

CASE SUMMARY

A 55-year-old man incidentally found a painless mass in his left submandibular region (SMR). He had a history of two surgeries for bilateral SLG cyst. Contrast enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) were performed. The patient received trans-cervical excision of left residual SLG in combination with excision of left submandibular gland (SMG). The postoperative course was uneventful and no signs of recurrence during 5 months of follow-up.

DISCUSSION

For a SMR mass, extraoral type of IDP in SLG should be considered in the differential diagnosis.

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.

Tlx1 regulates acinar and duct development in mouse salivary glands

Tlx1 encodes a transcription factor expressed in several craniofacial structures of developing mice. The role of Tlx1 in salivary gland development was examined using morphological and immunohistochemical analyses of Tlx1 null mice. Tlx1 is expressed in submandibular and sublingual glands but not parotid glands of neonatal and adult male and female C57Bl/6J (Tlx1+/+ ) mice. TLX1 protein was localized to the nuclei of terminal tubule cells, developing duct cells and mesenchymal cells in neonatal submandibular and sublingual glands, and to nuclei of duct cells and connective tissue cells in adult glands. Occasionally, TLX1 was observed in nuclei of epithelial cells in or adjacent to the acini. Submandibular glands were smaller and sublingual glands were larger in size in mutant mice (Tlx1-/- ) compared to wild-type mice. Differentiation of terminal tubule and proacinar cells of neonatal Tlx1-/- submandibular glands was abnormal; expression of their characteristic products, submandibular gland protein C and parotid secretory protein, respectively, was reduced. At 3 weeks postnatally, terminal tubule cells at the acinar-intercalated duct junction were poorly developed or absent in Tlx1-/- mice. Granular convoluted ducts in adult mutant mice were decreased, and epidermal growth factor and nerve growth factor expression were reduced. Along with normal acinar cell proteins, adult acinar cells of Tlx1-/- mice continued to express neonatal proteins and expressed parotid proteins not normally present in submandibular glands. Sublingual gland mucous acinar and serous demilune cell differentiation were altered. Tlx1 is necessary for proper differentiation of submandibular and sublingual gland acinar cells, and granular convoluted ducts. The mechanism(s) underlying Tlx1 regulation of salivary gland development and differentiation remains unknown.

Single-Cell RNA-Seq Analysis Identifies Angiotensinogen and Galanin as Unique Molecular Markers of Acinar Cells in Murine Salivary Glands

The submandibular gland (SMG) and sublingual gland (SLG) are two of three major salivary glands in mammals and comprise serous and mucous acinar cells. The two glands share some functional properties, which are largely dependent on the types of acinar cells. In recent years, while ScRNA-seq (single-cell sequencing) with a 10 × platform has been used to explore molecular markers in salivary glands, few studies have examined the acinar heterogeneity and unique molecular markers between SMG and SLG. This study aimed to identify the molecular markers of acinar cells in the SLG and SMG. We performed ScRNA-seq analyses in 4-week-old mice and verified the screened molecular markers using reverse transcription-quantitative real-time PCR, immunohistochemistry, and immunofluorescence. Our results showed prominently heterogeneous acinar cells, although there was great similarity in the cluster composition between the two glands at 4 weeks. Furthermore, we demonstrated that Agt is a specific marker of SMG serous acinar cells, whereas Gal is a specific marker of SLG mucous acinar cells. Trajectory inference revealed that Agt and Gal represent two types of differential acinar cell clusters during late development in adults. Thus, we reveal previously unknown specific markers for salivary acinar cell diversity, which has extensive implications for their further functional research.

The sublingual branch of the lingual nerve: Anatomical study and suggestion for a new terminology

The lingual nerve carries somatosensory fibers from the anterior two-thirds of tongue. The parasympathetic preganglionic fibers arising from the chorda tympani also travel with the lingual nerve in the infratemporal fossa to synapse in the submandibular ganglion to innervate the sublingual gland. However, only a few studies have investigated the specific nerve that innervates the sublingual gland and surrounding tissue i.e., the so-called sublingual nerve. Therefore, this study aimed to clarify the anatomy and definition of the sublingual nerves. Thirty sides from formalin fixed cadaveric hemiheads underwent microsurgical dissection of the sublingual nerves. The sublingual nerves were found on all sides and categorized into three branches, i.e., branches to the sublingual gland, branches to the mucosa of the floor of the mouth, and gingival branches. Additionally, branches to the sublingual gland were subcategorized into types I and II based on the origin of the sublingual nerve. We suggest that the lingual nerve branches should be categorized into five branches, i.e., branches to the isthmus of the fauces, sublingual nerves, lingual branches, posterior branch to the submandibular ganglion, and branches to the sublingual ganglion.

Amylase as a Diagnostic Tool for Plunging Ranula: Clinical Series and Description of the Technique

OBJECTIVES

This study describes a technique of measurement for neck cyst amylase content and reviews the experience of a tertiary referral center for cases of suspected plunging ranula.

METHODS

A retrospective study was performed at the Manukau Surgical Center in Auckland, New Zealand. Patients with a possible diagnosis of plunging ranula based on clinical presentation and diagnostic aspiration of the cyst contents were included. Demographic data, imaging and laboratory findings were collected, along with findings from surgery and histology. The technique for measuring the amylase of the aspirated cyst contents was also carefully recorded.

RESULTS

The 37 cases of confirmed plunging ranula included in this study had a submandibular cystic swelling that was aspirated. Imaging features consistent with a plunging ranula were seen in 89% of the study group. All cases had detectable levels of amylase of ≥3 U/L in the ranula contents. There was large variability (range: 5-560 U/L) in the concentration of amylase, with 70% of the cases demonstrating an amylase concentration below 200 U/L. Aspirates were typically described as viscous (87.5%) and yellow or straw-colored.

CONCLUSION

The combination of clinical presentation, imaging and the presence of amylase in the cyst contents is diagnostic for plunging ranula.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:535-538, 2023.

Functional Differences in the Role of Ductal Stem Cells in Mouse Major Salivary Glands

Salivary gland (SG) stem cells are the only cell population capable of extended growth in organotypic cultures, and thus they are considered a source for cell-based therapies aimed at SG regeneration. Studies in the mouse submandibular gland have identified only one population of tissue stem cells capable of salisphere formation in culture. These cells are actively dividing ductal cells that express epithelial progenitor markers keratin (K) 5/14 and normally function as lineage-restricted stem cells for differentiated ductal cells. In response to severe injury, however, these cells undergo a multipotency switch and contribute to regeneration of multiple cell lineages, including secretory units or acini. Little is known about the mechanism of cell renewal and regeneration in the other major SGs and whether comparable stem cell populations exist in the parotid (PG) and sublingual (SLG) glands. Using in vivo and ex vivo models, we show that both the PG and SLG contain a small population of K14-expressing ductal cells. Although they do not cycle frequently, K14-expressing ductal cells are the source of salisphere-forming cells in these glands. Long-term lineage tracing studies in adult mouse PGs showed a progenitor-progeny relationship between the K14-expressing ductal cells and the K19-expressing ductal cells in the striated ducts. In the SLGs, however, K14-expressing ductal cells did not generate a differentiated cell progeny for a 6-month period of observation and did not make a significant contribution to regeneration of gland after severe injury. These studies reveal the functional similarities and differences in tissue stem cells among the major SGs and have implications for developing strategies for SG regenerative therapies.

Adamantinoma-like Ewing sarcoma of the salivary glands: a case report and systematic literature review

Adamantinoma-like Ewing sarcoma (ALES) of the salivary glands is an exceedingly rare malignancy defined by the t(11,22) EWSR1::FLI1 fusion, with complex epithelial differentiation. To identify features that can allow for better recognition of this disease entity, we reviewed all published reports of molecularly confirmed ALES of the salivary glands and explored epidemiological, clinical, radiological, pathological, and therapeutic characteristics of a population of 21 patients including a single newly reported patient from our group. We searched the English-language literature indexed in PubMed, Medline, Scopus, and Web of Science using the keyword 'Adamantinoma-like Ewing sarcoma' published up to June 2022. The median age at diagnosis was 46 years, and a slight female sex predilection was observed. Most tumors originated in the parotid gland (86%) and presented as a painless palpable mass with a median diameter of 3.6 cm. Metastatic dissemination was reported only in one patient (5%), and after a median follow-up of 13 months the 1-year overall survival rate was 92%. Salivary gland ALES were frequently misdiagnosed at presentation (62% of cases) and were pathologically characterized by the presence of highly monomorphic small round blue cells with infiltrative pattern and positive immunostaining for CD99 and high- and low-molecular weight cytokeratins. Epidemiological and clinical features of salivary gland ALES raise questions on the incorporation of this malignancy in the Ewing sarcoma family tumor group.

Solitary Extrapleural Fibrous Tumor in Salivary Glands: Our Experience-Case Series and Literature Review

(1) Background: Extrapleural solitary fibrous tumors (ESFTs) are rare oncological entities occurring in the head and neck, and even more so in the salivary glands. The clinical presentation and histologic features are usually unspecific, resulting in frequent misclassification. As an unusual tumor, ESTFs have an unpredictable clinical behavior. (2) Methods: We present two clinical cases referred to our Maxillofacial Surgery Unit for the onset of a symptomless mass involving, in one case, the parotid gland, and in the other case, the sublingual gland. (3) Results: Solitary fibrous tumors could be considered as neoplasms with intermediate biological behavior that are not entirely predictable on the basis of morphological features, as these are mostly still unknown. However, a few histologic, immunohistochemical, and imaging features, such as a hypodense signal at the T1 sequence in an MRI, or positivity for CD34, bcl2, and CD99, and the NAB2-STATS6 fusion gene, could be useful for an early differential diagnosis of ESTFs. (4) Conclusions: All patients were alive at follow-up with no evidence of disease. Surgical management should always be considered as the first choice for oncological radicality, and clinical behavior should always be defined with the help of the study of radiological and anatomopathological features.

Application of Diffusion Kurtosis Imaging in Evaluating Acute Xerostomia in Nasopharyngeal Carcinoma Treated With Induction Chemotherapy Plus Concurrent Chemoradiotherapy

Purpose

The aim of this study was to identify the efficacy of diffusion kurtosis imaging (DKI) in tracking and monitoring the dynamic change of parotid glands (PGs), submandibular glands (SMGs), sublingual glands (SLGs), and acute xerostomia in nasopharyngeal carcinoma (NPC) patients treated with induction chemotherapy (IC) plus concurrent chemoradiotherapy (CCRT).

Methods

The prospective study recruited 42 participants treated with IC+CCRT. All patients underwent DKI scanning six times: before IC, before RT, in the middle of the RT course, immediately after RT, and 1 and 3 months post-RT. Mean diffusion coefficient (MD) and mean kurtosis (MK) of PG, SMG, SLG, saliva flow rate measured under resting (uSFR) and stimulated condition (sSFR), and xerostomia questionnaire (XQ) scores were recorded.

Results

At each time point, sSFR was significantly higher than uSFR (p < 0.05 for all). MD of the salivary glands and XQ scores increased over time while MK, uSFR, and sSFR decreased. After IC, the significant differences were detected in MD and MK of bilateral SMG and MK of the left SLG (p < 0.05 for all), but not in MD and MK of PG, uSFR, sSFR, and XQ scores. After RT, sSFR at 1m-RT decreased significantly (p = 0.03) while no significant differences were detected in uSFR and XQ scores. Moderate-strong correlations were detected in ΔMD-PG-R%, ΔMK-PG-R%, ΔMD-PG-L%, ΔMK-PG-L%, ΔMD-SMG-R%, ΔMK-SMG-R%, ΔMD-SMG-L%, ΔMK-SMG-L%, and ΔMD-SLG-R%, with correlation coefficients (p < 0.05 for all) ranging from 0.401 to 0.714. ΔuSFR% was correlated with ΔMD-SMG% (p = 0.01, r = -0.39), ΔMD-SLG% (p < 0.001, r = -0.532), and ΔMK-SMG% (p < 0.001, r = -0.493). ΔsSFR% correlated with ΔMD-PG% (p = 0.001, r = -0.509), ΔMD-SMG% (p = 0.015, r = -0.221), and ΔMK-PG% (p < 0.001, r = 0.524). ΔXQ% was only correlated with ΔMK-PG% (p = 0.004, r = 0.433).

Conclusion

DKI is a promising tool for tracking and monitoring the acute damage of PG, SMG, and SLG induced by IC+CCRT in NPC patients.

Sublingual Gland Carcinoma Revealed by Choroidal Metastasis

A 65-year-old man presented with a 1-week history of left eye distortion. An elevated choroidal lesion covering 6 disc diameters was found in the posterior retina of the left eye. Systemic examination revealed sublingual gland carcinoma and multiple lung metastases, and the diagnosis was choroidal metastasis from sublingual gland carcinoma. Following chemotherapy and radiation therapy, the choroidal lesion shrunk and the patient's visual acuity improved. The patient died 23 months after his first visit. To the best of our knowledge, this is the first reported case of choroidal metastasis from sublingual gland carcinoma.

Transoral Complete vs Partial Excision of the Sublingual Gland for Plunging Ranula

OBJECTIVES

Plunging ranula is a pseudocyst of saliva extravasated from the sublingual gland (SLG) to the submandibular space. This is treated by transoral excision of the SLG or transcervical cyst excision that might differently affect surgical morbidity and recurrence. This study compared the clinical outcomes of complete vs partial excision of the SLG for plunging ranula.

STUDY DESIGN

A nonrandomized comparative study.

SETTING

Academic medical center.

METHODS

This study included 42 patients with plunging ranula who underwent complete or partial excision of the SLG with the evacuation of cystic content. Two surgical methods of complete or partial SLG resection were alternatively allocated to consecutive patients without randomization. The primary outcome was a postoperative recurrence. Secondary outcomes were operation time and complications.

RESULTS

Complete and partial excision of the SLG was performed in 22 and 20 patients, respectively, without injury to the Wharton's duct or the lingual nerve. Postoperative complications in 42 patients were minor with temporary events: hematoma, 1 (5%); tongue numbness, 2 (5%); dysgeusia, 4 (9%); and dysphagia, 2 (5%), which did not differ between patients with complete and partial excision of the SLG (P > .1). However, recurrence occurred in only 5 of 20 patients with partial SLG excision but none of 22 patients with complete SLG excision for a median follow-up of 36 months.

CONCLUSIONS

Complete SLG excision is preferred over partial SLG excision to treat plunging ranula for reducing postsurgical risks of complications and recurrence.

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.

Basal cell adenoma of sublingual salivary gland: A rare entity

Monomorphic adenoma or Basal cell adenoma (BCA) is a benign epithelial tumor of glandular origin. It has very unique histological characteristic and its diagnosis is mainly established by histological examination. Most common occurrence is in parotid gland and rarely reported in submandibular and sublingual salivary glands. In this case report, we are presenting a case of basal cell adenoma of sublingual gland.

Carcinoma Showing Thymus-Like Differentiation (CASTLE) Arising in the Sublingual Gland

Carcinoma showing thymic-like differentiation (CASTLE) is a rare tumor most commonly occurring in the thyroid and soft tissues of the neck. We report the first case of CASTLE occurring in the sublingual gland. The patient, a 35-year-old healthy man, presented with a submucosal lesion located in the anterior right floor of the oral cavity and an ipsilateral neck mass. The lesion had been previously investigated by neck computed tomography and ultrasound-guided fine needle aspiration cytology and diagnosed as metastatic squamous cell carcinoma. After oral cavity magnetic resonance imaging, positron emission tomography, and a non-diriment, fine needle aspiration cytology of the sublingual mass, the patient was treated as affected by a sublingual gland malignancy with removal of primary tumor and neck dissection. Morphological and immunohistochemical findings were diagnostic for primary sublingual gland CASTLE. The patient received adjuvant radiotherapy and is free of disease 2 years after treatment. We describe the pathological features of the lesion and discuss the possible differential diagnoses.

Systemic Effects of Photobiomodulation on the Morphology of the Thyroid and Sublingual Glands: A Study in Rabbits

Objective: To investigate whether photobiomodulation (PBM) applied in a clinical situation with the purpose of improving the healing process of implants placed in the rabbit mandible would cause any morphological change in the thyroid and sublingual glands as a systemic effect of laser irradiation. Methods: Thirty-two New Zealand rabbits were randomly divided into four groups of eight animals each, one control group (CI, nonirradiated animals) and three experimental groups (EI, EII, and EIII) that received PBM postoperatively with an aluminum/gallium/arsenide laser diode (Theralase^®) at a wavelength of 830 nm (infrared) and 50 mW output power applied to two irradiation fields per session, for a total of seven sessions. All rabbits underwent surgical extraction of the mandibular left incisor, followed by immediate placement of an osseointegrated implant in the fresh socket. The experimental groups EI, EII, and EIII received PBM at an energy density of 5, 2.5, and 10 J/cm², respectively, per irradiation field. Results: There was no histomorphometric change in any of the groups. Conclusions: PBM, based on the irradiation protocol used in this study, does not cause morphological changes in the thyroid and sublingual glands when used to stimulate peri-implant bone healing in the rabbit mandible.

AHNS series: Do you know your guidelines? Diagnosis and management of salivary gland tumors

This article is the next installment of the series "Do you know your guidelines" presented by the Education Committee of the American Head and Neck Society. Guidelines for the workup and management of tumors of the major and minor salivary glands are reviewed.

Pediatric Salivary Cancer: Epidemiology, Treatment Trends, and Association of Treatment Modality with Survival

Objective To characterize the epidemiology of pediatric salivary cancer and associate patient, tumor, and treatment factors with treatment modality and survival. Study Design Cross-sectional analysis. Setting US national database. Subjects and Methods We identified 588 patients 19 years or younger diagnosed with salivary cancer in the National Cancer Database 2004-2013. We characterized patient, tumor, and treatment factors as proportions and associated these factors with treatment modality and overall survival via multivariable logistic regression and multivariable Cox proportional hazards regression, respectively. Results In total, 588 patients were included. Mucoepidermoid carcinoma was identified in 234 of 588 patients (40%) and acinar cell carcinoma in 215 of 588 (37%). Parotid tumors were seen in 504 (86%) of patients. Surgery alone was used to treat 351 (60%) of patients; surgery plus adjuvant radiation was used to treat 145 (25%). Overall 5-year survival was 93%. Controlling for patient and tumor characteristics, treatment with surgery and radiation vs surgery alone was associated with improved overall survival (hazard ratio [HR] = 0.15; 95% confidence interval [CI], 0.02-0.92; P = .041). High tumor grade was associated with decreased overall survival (HR = 33.17; 95% CI, 5.89-186.8; P < .001). Treatment with surgery plus radiation remained associated with improved overall survival in the subset of patients with high tumor grade (HR = 0.12; 95% CI, 0.02-0.64; P = .014). Conclusion Tumor grade is an important predictor of survival in pediatric patients with salivary gland cancer. Surgery plus adjuvant radiation vs surgery alone is associated with improved overall survival and may be considered for high-risk patients, particularly those with high-grade tumors.

Surgical management of plunging ranulas: a 10-year case series in South East Queensland

BACKGROUND

Plunging ranulas are rare mucous extravasation pseudocysts that arise in the floor of the mouth and pass into the submandibular space of the neck. The aim of this study was to investigate the diagnosis, surgical management and outcomes of patients with a plunging ranula at our institution in South East Queensland over a 10-year period.

METHODS

A retrospective analysis of adult patients diagnosed with and treated for plunging ranula between 2006 and 2016 at Logan Hospital was conducted. Patient demographics, preoperative investigations, surgical management and post-operative outcomes were collected from medical records.

RESULTS

A total of 18 adult patients were treated for plunging ranula. Of the 18 cases, 17 were treated via transoral excision of the sublingual gland. The mean age at presentation was 28.8 years with a 3:1 female to male predominance. Fifty-six percent of patients were of Polynesian descent. The success rate was 94% with only one patient experiencing recurrence and requiring re-excision of remnant sublingual gland tissue. Three patients (17%) developed complications related to post-operative bleeding. There was a slight predominance for right-sided disease (56%) compared with left and one case of bilateral plunging ranulas in this series.

CONCLUSION

This study demonstrates that excision of the sublingual gland is an effective and safe treatment for plunging ranula. The majority of plunging ranulas occur in patients aged <30 years with a higher incidence in patients of Polynesian heritage, which is consistent with previous studies suggesting a possible underlying genetic predisposition for this condition.

Mucoepidermoid carcinoma of the sublingual gland harboring a translocation of the MAML2 gene: A case report

Among tumors of the major salivary glands, tumors in the sublingual gland are rare. Although mucoepidermoid carcinoma (MEC) represents a histological type of salivary gland tumor, it is occasionally difficult to diagnose due to its histological variation. The present study reports a case of MEC harboring a mastermind-like transcriptional coactivator 2 (MAML2) gene translocation in the sublingual gland. A 76-year-old Japanese woman with a mass in the left submandibular region was referred to Kurume University Hospital (Kurume, Japan). Computed tomography scans revealed that the tumor was predominantly located in the sublingual gland, and tumor resection was performed. Histologically, the tumor was composed of cells that exhibited low-grade nuclear atypia and clear and/or granular eosinophilic cytoplasm, and that were proliferating in solid patterns. Periodic acid-Schiff and alcian blue staining revealed a small number of mucinous cells in the tumor. Immunohistochemically, the tumor cells were positive for p40 and p63. Fluorescence in situ hybridization (FISH) analysis revealed a MAML2 gene split. The definitive pathological diagnosis was low-grade MEC, as the case lacked any factors indicative of high-grade malignancy. To the best of our knowledge, this is the first report of MEC in the sublingual gland with MAML2 gene translocation confirmed by FISH.

Isolated Langerhans cell histiocytosis of the sublingual gland in an adult

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the proliferation of pathologic Langerhans cells. Its clinical presentation is highly variable, that range from single-system, limited disease to severe, multi-organ disease with high mortality. LCH usually affects children and young adults. The most frequent sites for LCH are the bone, skin, lung, pituitary gland, and lymph nodes. Salivary gland involvement by LCH is extremely rare, and only a few cases of LHC involving the parotid glands have been reported in the English literature. To our knowledge, the involvement of the sublingual gland as a part of single or multisystem LCH has not been previously described. Herein we reported the first case of primary LCH of the sublingual gland. A 40-year-old woman presented with a 2-month history of a painless mass on the right sublingual area. Excision of the lesion including the right sublingual gland was performed. Histopathological diagnosis of LCH was rendered. The patient remains free of symptoms 17 months after surgery.

Epithelial-myoepithelial carcinoma of floor of mouth: A case report with cytological, histological and immunohistochemical correlation

A 61-year-old female presented with a 3-year-old swelling in the right floor of mouth. Clinical examination and fine needle aspiration cytology suggested a benign lesion. The mass was excised locally along with the involved sublingual and deep part of submandibular gland and duct. Post-operative histopathological examination revealed features of pleomorphic adenoma. However, on revision of histological sections, features were predominantly of a rare malignancy of the salivary glands, epithelial-myoepithelial carcinoma (EMC), along with focal areas of adenoid cystic carcinoma (Ad CC). The tumor was p-63, s-100 and smooth muscle actin positive but C-kit was negative, which ruled out Ad CC and the possibility of a hybrid carcinoma. The aim of this article is to describe a rare case of EMC in the floor of mouth and the confusing cytological picture that it created.

[Carcinoma ex pleomorphic adenoma occurring in the sublingual gland: a case report]

Carcinoma ex pleomorphic adenoma occurring in the sublingual gland is extremely rare. In this report, a case of adenoid cystic carcinoma ex pleomorphic adenoma of the sublingual gland was presented.

Types of sublingual gland herniation observed during sonography of plunging ranulas

OBJECTIVES

Plunging ranulas have been shown to have a common trio of mylohyoid defects, sublingual gland herniation, and submandibular space fluid collections. The herniated sublingual gland may be susceptible to subclinical trauma. The purpose of this study was to investigate the frequency of occurrence of various types of active sublingual gland herniation observed during diagnostic sonographic studies.

METHODS

Sonographic findings of sublingual gland herniation from 76 patients with a total of 80 plunging ranulas are presented. All sublingual gland herniations, including those on the contralateral side, were documented at the time of the examinations and reviewed later. The sonographic appearances of active sublingual gland herniation were given the names "slide," "wobble," "mushroom," and "retrusion" to reflect the observed movement.

RESULTS

Mylohyoid defects were found in 98% of plunging ranulas. The different types of sublingual gland herniation observed were as follows: slide in 77.8%, wobble in 11.1%, mushroom in 9.7%, and retrusion in 1.4%. The unaffected contralateral side showed a wobble in 44.8% of cases and slide in 8.9%.

CONCLUSIONS

Sublingual gland herniation through mylohyoid defects is easily missed if one is unaware. Prior knowledge of the various types of sublingual gland herniation and their frequencies of occurrence are very helpful during diagnostic sonographic examinations.

Aggressive monophasic synovial sarcoma involving sublingual gland: First case

Synovial sarcoma (SS) of the arising head and neck region is rare. The most common site being the hypopharynx. No case of SS from the sublingual of 35-year old salivary gland has been reported. We report a case of monophasic SS in sublingual gland a female making it the first documented case of English Language literature.

First description of a hybrid tumor of the sublingual gland

BACKGROUND

Hybrid tumours of the salivary glands are rare neoplasms. They are composed of at least two different tumour entities located in the same topographic area and account for only 0.1% of all salivary gland tumours. The most common component is an adenoid cystic carcinoma. There are several possible forms of hybrid tumours, which are most commonly located in the parotid gland.

CASE REPORT

We report on a 59-year-old female, who presented with a lesion of the caruncula of the left sublingual gland. The biopsy showed an adenoid cystic carcinoma in combination with a salivary duct carcinoma. Treatment consisted of tumour resection, bilateral selective neck dissection and adjuvant radiotherapy. Histopathologically, at least 30% of the tumour mass was composed of a salivary duct carcinoma and 70% of an adenoid cystic carcinoma. At 58 months after treatment, the patient is alive without evidence of recurrent disease.

CONCLUSION

To our knowledge, the presented case is the first description of a hybrid tumour of the sublingual gland. Furthermore, the post-therapeutic course is encouraging, as hybrid tumours of the salivary glands usually have a poor prognosis.

Postmortem investigation of mylohyoid hiatus and hernia: aetiological factors of plunging ranula

The mylohyoid hiatus and hernia were discovered in the nineteenth century and were considered to explain the origin of the plunging ranula from the sublingual gland. This formed the rationale for sublingual sialadenectomy for the treatment of plunging ranula. However, a more recent, extensive histological investigation reported that hernias contained submandibular gland, which supported an origin of the plunging ranula from the submandibular gland and submandibular sialadenectomy for the treatment of plunging ranula. We therefore decided to investigate the occurrence and location of the hiatus and the histological nature of the hernia. Twenty-three adult cadavers were dissected in the submandibular region. The locations and dimensions of mylohyoid hiatuses were measured before taking biopsies of hernias. Hiatuses with associated hernias were found in ten cadavers: unilateral in six; and bilateral in four, in one of which there were three hiatuses. Sublingual gland was identified in nine hernias and fat without gland in six. This investigation supports clinical and experimental evidence that the plunging ranula originates from the sublingual gland and may enter the neck through the mylohyoid muscle. It confirms the rationale of sublingual sialadenectomy for the treatment of plunging ranula.

Multiple sialolithiasis in sublingual gland causing dysphagia

Background:

Sialolithiasis is a common disease of the major salivary glands, but it is rarely seen in the sublingual gland. Patients commonly experience pain and/or swelling, but dysphagia is presented in extended lesions.

Case Report:

In this report we present a 67-year-old woman who had 268 sialoliths in the sublingual gland, forming a huge mass and causing dysphagia. The diameter of the largest sialolith was approximately 4 mm. The diagnosis of sialolithiasis was confirmed pathologically.

Conclusions:

Multiple sublingual gland sialoliths are considered rare; they may cause symptoms like dysphagia and speech difficulty. To our knowledge our patient had more sialoliths in a sublingual gland than any previous reports in the literature.

Mouth floor enlargements related to the sublingual glands in edentulous or partially edentulous patients: a microscopic study

Mouth floor enlargements (MFE) are observed in edentulous and partially edentulous patients, impairing denture fitting, and have recently been described in the literature as hyperplasias of the sublingual glands.

OBJECTIVE

This study aims at describing the microscopic aspects of MFE that contribute to their final diagnosis.

METHODS

Twenty-four specimens were surgically removed from the enlarged mouth floor of 19 patients (15 females and 4 males). Patient age ranged from 48 to 74 years, with a mean of 57 years. The main surgical indication was to permit or improve the fitting of dentures. Six patients were completely edentulous and 13 were partially edentulous. The material was processed for microscopic examination and stained with hematoxylin-eosin, Mallory's trichrome and periodic-acid Schiff (PAS).

RESULTS AND CONCLUSIONS

The epithelium of the mouth floor was normal in 17 cases, hyperplastic in 4 and atrophic in 3. Six of the 24 sublingual glands removed were microscopically normal, while the other specimens presented acinar atrophy with hyperplasia of duct-like structures. Interstitial fibrosis was observed in 18 cases and was accompanied by adipose tissue infiltration in 15. Decreased lymphoid tissue was observed in 16 samples and oncocytosis was present in 5 cases. We suggest that MFE in edentulous or partially edentulous patients should be considered as an entity for the text books.