Sublingual salivary gland enlargement

When examining the mouth floor, sublingual salivary gland enlargement, or hypertrophy, is commonly seen by dentists. It represents an innocuous, asymptomatic lesion that tends to proliferate into edentulous areas. It is often mistaken for a pathologic entity. Recognition avoids concern, misdiagnosis and unnecessary surgery.

The diagnosis and surgical management of major salivary gland pathology

BACKGROUND

Major salivary gland pathology is an uncommon but important finding which may initially present to general dental and medical practitioners. The consequences of misdiagnosis are important, as acute obstruction and neoplasia are the main pathological lesions diagnosed. The purpose of this study was to analyze a consecutive series of major gland pathologies treated surgically to determine diagnostic and treatment problems.

METHODS

A retrospective analysis of all cases of the major salivary glands treated on an inpatient surgical basis over a five-year period by the Oral and Maxillofacial Surgery Unit of the Royal Adelaide Hospital was performed. Particular emphasis was placed on the referring diagnosis as compared to the final diagnosis.

RESULTS

Fifty-four patients had surgical management of 62 major salivary glands over the five-year period. By gland, 18 (33.3 per cent) were parotid, 35 (51.1 per cent) submandibular and nine (16.6 per cent) were sublingual. Fifty-one (82 per cent) of all lesions were inflammatory and 11 (18 per cent) neoplastic. The most common presentations were swelling (72 per cent) and pain (33 per cent). Most patients were referred by general dentists (37 per cent), followed by general medical practitioners (32 per cent) and specialists (28 per cent). The referring diagnosis was correct for only 45 per cent of the dentists but 76 per cent for the general medical practitioners and 87 per cent for the specialists. Only two of the 11 gland neoplasms were correctly identified as neoplasms, both by specialists. The morbidity of the surgical treatment was low.

CONCLUSION

The general dental practitioner is often the first health professional with the opportunity to assess salivary gland pathology, and therefore needs to be aware of the presenting signs and symptoms of major salivary gland lesions.

Ultrasonography of salivary glands in primary Sjogren's syndrome. A comparison with magnetic resonance imaging and magnetic resonance sialography of parotid glands

OBJECTIVES

To evaluate ultrasonography (US) of salivary glands in primary Sjögren's syndrome (SS) and to compare US with parotid magnetic resonance (MR) imaging and MR sialography.

METHODS

US examination of parotid, submandibular and sublingual glands was performed on 27 patients with primary SS, 27 healthy controls and 27 symptomatic controls without SS. The results were compared with parotid MR imaging and MR sialography and the clinical features of the patients.

RESULTS

Salivary gland abnormalities, parenchymal inhomogeneity or adipose degeneration, were visualized in 21 (78%) SS patients, in one healthy control and in two symptomatic controls by US. Eighteen (67%) patients had changes in the parotid and submandibular glands and 8 (30%) changes in the sublingual glands. In the comparison, MR sialography was found to be the most sensitive method (96%), followed by MR imaging (81%) and US (78%), in detecting glandular changes. The specificity of US was 94%. The US and MR results were related to anti-Ro/SSA positivity but not to saliva secretion. The focus scores were related only to parotid MR imaging findings.

CONCLUSIONS

US, MR imaging and MR sialography with modern technology have reached such a good accuracy in visualizing glandular structural changes that they are promising alternatives to the conventional invasive examinations in the diagnostics of SS.

Adenoid cystic carcinoma associated with salivary duct cyst in the sublingual gland

We described an extremely rare case of adenoid cystic carcinoma associated with salivary duct cyst in the sublingual gland of a 40-year-old Japanese woman. The tumor was growing from the cyst wall and almost occluded the cyst lumen. The epithelium lining the cyst lumen contained both keratin 19-positive cells and alpha-smooth muscle actin-positive cells, indicating the cyst being derived from the acinus/intercalated duct of the sublingual gland. Therefore, our case has presented for the first time a direct evidence that adenoid cystic carcinoma arises from acinus/intercalated duct.

[Cervical ranula]

Three patients, 2 men aged 21 and 39 years, respectively, and 1 woman aged 29 years, presented with a unilateral swelling of the neck, with no accompanying symptoms. In the youngest man the diagnosis of a 'plunging ranula' was made after repeated fine needle aspiration yielded viscous yellowish mucus with a high amylase content. In the oldest man the diagnosis was made during the operation and in the woman the diagnosis was finally made after two surgical explorations in the neck. In all 3, no recurrence occurred after removal of the involved salivary glands. A cervical ranula is an extension of a pseudocyst of the glandula sublingualis. Important clues for the diagnosis of a 'plunging ranula' are: the simultaneous presence of a ranula in the floor of the mouth (or a history of one), a characteristic cystic mass in the submandibular space with an extension into the sublingual space on CT and/or MRI, and the aspiration of amylase-containing mucus. Excision of the sublingual gland as the source of salivary leakage is the therapy of choice in a case of 'plunging ranula', with drainage of mucus from the ranula into the oral cavity. As the 'plunging ranula' represents a pseudocyst without an epithelial lining, excision is not indicated.

Effect of thyroidectomy on the histology of rat sublingual gland

This study was carried out to investigate the effect of thyroidectomy on the histology of rat sublingual gland. Twenty-eight male Wistar albino rats, aged 4 weeks and weighing between 45-55 g, were used. The rats were divided into two experimental groups (control and thyroidectomy), each containing 14 animals. Total thyroidectomy of rats was performed under ether anesthesia in thyroidectomy group. The rats in the control group were sham operated without having the thyroidectomy. Seven rats randomly selected from both groups were fixed using the perfusion fixation technique 2 and 6 weeks after thyroidectomy, and their sublingual glands were harvested for histological investigation. No histological difference was observed between the two groups 2 weeks after thyroidectomy. However, 6 weeks after thyroidectomy considerable cytoplasmic vacuolization of the epithelial cells of the mucous tubules was seen in the thyroidectomy group compared to the controls. Enlargement of mucous tubules was also observed, and the lumina in most of the tubules was quite dilated. In the stroma surrounding the parenchymal tissues, increased lipid tissue mass was observed. In addition, increased connective tissue mass and mononuclear cell infiltrations were evident. Furthermore, the number of mast cells was significantly higher in the thyroidectomy group than in the controls 6 weeks after thyroidectomy. It was concluded that the thyroid gland and hormones might have an influence on the histology of the sublingual gland.

A basal cell adenoma of the sublingual gland

To the knowledge of the authors, only one case of a basal cell adenoma of the sublingual gland has ever been reported. We report a second case of a basal cell adenoma arising from the sublingual gland in this paper.

Morphological changes in mouse sublingual gland parenchyma subjected to chorda tympani resection

Morphological changes in the mouse sublingual gland parenchyma subjected to parasympathetic nerve block were investigated. Mice were subjected to unilateral resection of the chorda tympani, near its point of joining with the lingual nerve. After 1, 2, 3, 5, 10 or 20 weeks, the mice were killed and their sublingual glands were removed and processed for light and electron microscopy. Two weeks after resection, the space between the adjoining lobules of the glands on the treated side began to be expanded, and by 10 weeks were 10 times the size of the spaces in the glands of the untreated mice. Three weeks after resection, the lobule area decreased to about 72% of the area of glands in the untreated mice and the acinus area to about 52%. However, no significant difference was seen between the numbers of acini in each group. Electron microscopy showed that the glands on the treated side contained fewer secretory granules than the glands in the untreated mice, though there was no difference in size. Neither the lobules of the glands on the treated side nor those of the glands of the untreated mice contained many TUNEL-positive cells. These findings suggest that following parasympathetic nerve resection, mouse sublingual gland acinar cells undergo atrophy with a reduction size rather than cell death.

The roles of apoptosis and mitosis in atrophy of the rat sublingual gland

The roles of apoptosis and mitosis of acinar and duct cells in the atrophy of the sublingual gland of rat induced by double duct ligation was investigated using immunohistochemistry for proliferating cell nuclear antigen (PCNA), terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick end labeling (TUNEL), and transmission electron microscopy (TEM). Many PCNA-positive duct cells were observed 3 days after duct ligation, and the numbers decreased thereafter. At 3 and 5 days, several TUNEL-positive acinar cells were observed and typical apoptotic acinar cells were identified by TEM. Necrotic acinar cells were also observed ultrastructurally. After 7 days, there were few acini but many ducts, as well as many structures representing transition from acinus to duct. These observations demonstrate that acinar cell loss by apoptosis and duct cell proliferation by mitosis occur in atrophic sublingual glands as well as in other atrophic salivary glands. In addition, it appears that the transition from acinar to duct cell and the necrosis of acinar cells play important roles in the atrophy of the sublingual gland.

Activation of peroxisome proliferator-activated receptor gamma impedes Porphyromonas gingivalis lipopolysaccharide interference with salivary mucin synthesis through phosphatidylinositol 3-kinase/erk pathway

Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the superfamily of nuclear receptor transcription factors, plays a critical role in the regulation of the expression of genes associated with inflammation. Using mucous acinar cells of sublingual salivary gland, we investigated the effect of PPARgamma activation on the disturbances in salivary mucin synthesis evoked by lipopolysaccharide (LPS) of periodontopathic bacterium, P. gingivalis. Exposure of the acinar cells to the LPS led to a dose-dependent decrease (up to 58.4%) in mucin synthesis, accompanied by a massive enhancement in apoptosis and NO production, and an induction in inducible nitric oxide synthase (NOS-2) activity. Activation of PPARgamma with a specific synthetic agonist, ciglitazone, prevented in a dose-dependent fashion the LPS-induced reduction in mucin synthesis, and the effect was reflected in a marked decrease in apoptosis, NO generation, and the expression of NOS-2 activity. The impedance by ciglitazone of the LPS-induced changes in mucin synthesis was blocked by PD98059, an inhibitor of extracellular signal regulated kinase (ERK), as well as wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K). Moreover, both agents caused further enhancement in the LPS-induced nitric oxide generation and countered the inhibitory effect of ciglitazone on the LPS-induced upregulation in NOS-2. The findings suggest that the impedance of P. gingivalis LPS inhibition of salivary, mucin synthesis by PPARgamma agonist, ciglitazone, involves activation of ERK pathway by PI3K.

Hemangioma with phleboliths in the sublingual gland: as a cause of submental opacity

Hemangiomas are the most common lesions of the major salivary glands during infancy and early childhood. Changes in blood flow dynamic within hemangioma results in thrombus and phleboliths. There have been a number of reports of hemangiomas with phleboliths in parotid and submandibular glands. We present the first case of a hemangioma with multiple phleboliths in the subligual gland as a cause of submental opacity, and discussed the diagnosis of radiopaque masses in the sublingual and submental regions.

Proliferation and distribution of myoepithelial cells during atrophy of the rat sublingual gland

BACKGROUND

The present study was aimed to determine the proliferation and distribution of myoepithelial cells during atrophy of rat sublingual glands.

METHODS

The excretory duct of the right sublingual gland of rats was doubly ligated with metal clips to induce atrophy in the gland. The atrophic sublingual glands were taken from 1 to 28 days after duct ligation and examined with single immunohistochemistry for actin as a marker of myoepithelial cells and with immunohistochemical double staining for actin and proliferating cell nuclear antigen (PCNA) as a marker of proliferating cells.

RESULTS

In unligated sublingual glands, myoepithelial cells embraced acini and intercalated ducts, but not striated and interlobular excretory ducts. In the early stages of atrophy, myoepithelial cells surrounded small ducts but not large ones. However, in the later stages of atrophy, myoepithelial cells were also observed at the periphery of the large ducts. The immunohistochemical double staining showed that there were PCNA-positive myoepithelial cells in the normal as well as in the atrophic sublingual glands. However, the PCNA labeling indices of myoepithelial cells were low in the unligated and atrophic sublingual glands, and there were no statistically significant differences in these labeling indices.

CONCLUSION

The observations suggest that the distribution of myoepithelial cells change during atrophy of rat sublingual glands and that myoepithelial cells have low proliferative activity in both the normal and atrophic condition of rat sublingual glands.

Solitary fibrous tumor with malignant potential arising in sublingual gland

A rare case is described of a solitary fibrous tumor (SFT) with malignant potential arising in the sublingual gland. A 59-year-old man presented with a 4-month history of a slowly enlarging painless mass in the center of the floor of the mouth. The tumor was a well-demarcated, firm mass with a multicystic lesion. The tumor exhibited highly cellular areas of spindle cells with patternless architecture alternating with hypocellular areas. The tumor cells were positive for CD34 and bcl-2 as well as vimentin, and negative for epithelial, myogenic, neurogenic and histiocytic markers. The tumor cells formed multiple satellite nodules around dilated ducts in the multicystic lesion, indicating infiltrative growth. In addition, areas exhibiting higher cellularity with increased mitoses were noticed in the satellite nodules, although cellular atypia was not obvious. These findings led to a final diagnosis of SFT with malignant potential. There has been no recurrence or metastasis for 27 months after the surgery. Solitary fibrous tumor of the salivary gland must be differentiated from various spindle cell neoplasms including myogenic, peripheral nerve sheath, fibroblastic and fibro-histiocytic spindle cell neoplasms, hemangiopericytoma and myoepithelioma. In addition to characteristic morphological features, an immunohistochemical positivity for CD34 and bcl-2 may aid in the diagnosis of SFT.

Anterior lingual mandibular salivary gland defect (Stafne defect) presenting as a residual cyst

Lingual mandibular salivary gland inclusion (Stafne defect) is a developmental anomaly represented by a bone concavity usually containing submandibular gland tissue. The posterior mandible region, particularly at the angle and below the mandibular canal, is the common location, and the anterior mandibular variants occur rather seldom. The latter is usually observed in the premolar and cuspid region, or more rarely in the symphysis, as a round or ovoid radiolucency sometimes appearing superimposed over the teeth's apices, resembling a true cystic lesion or an odontogenic tumor. We report an additional case of anterior lingual mandibular salivary gland defect occurring in a 42-year-old white man. It presented as an asymptomatic radiolucency located on the left side of the mandible, in the region of an absent second premolar and first molar, above the alveolar canal, mimicking a residual cyst. Histopathologic examination of the "cyst" content revealed the absence of a cyst lining and the presence of normal sublingual gland tissue.

Multiple sialoliths in sublingual gland: report of a case

We describe a 28-year-old woman with multiple sialoliths in the left sublingual gland. The sialoliths were removed by transoral sublingual sialadenectomy. A total of 22 calculi were found.

[An uncommon clinical manifestation of the sublingual salivary gland cyst]

A female patient with ranula (cyst of the sublingual salivary gland) without characteristic clinical signs of ranula in the oral cavity is described. The diagnosis was made only during intervention.

Sublingual gland involvement in systemic Wegener's granulomatosis: a case report

Wegener's granulomatosis is a systemic vasculitis characterized by necrosis, granulomatosis and inflammation. The usual targets are extra-oral, although salivary gland involvement has been recognized, usually confined to parotid and submandibular glands. A case report is presented of sublingual gland presentation, confirmed on biopsy, which proceeded to systemic involvement. Some evidence suggests that salivary gland involvement, if recognized, may lead to an early diagnosis and the potential for earlier therapeutic intervention.

Recurrent congenital bilateral ranula: a case report

A case of congenital bilateral ranula in a one-week-old male baby is reported. At presentation the cyst measured 3.5 x 2.5 cm but did not interfere with feeding. Initial marsupialisation resulted in recurrence of the cyst. It was subsequently re-excised completely together with the associated sublingual salivary gland. The cyst has not recurred six months after treatment. The usually large size of the cyst and its bilateral presentation makes this an interesting case.

Relationship between sialoadenitis and periductal laminin expression in the submandibular salivary gland of NZBxNZWF(1) mice

This study was designed to investigate the relationship between cellular infiltration and periductal laminin expression of the submandibular salivary gland in female autoimmune NZBxNZWF(1) mice, which are used as an animal model for secondary human Sjögren's syndrome. In NZBxNZWF(1) mice, but not in non-autoimmune control (BALB/c) mice, early submandibular salivary gland lesions were characterized by infiltration of mononuclear cells around vessels and ducts in the interstitial tissues, increasing with age. Destruction and hyperplasia of ductal epithelial cells occurred, with extensive local infiltration of mononuclear cells. Laminin expression around the ducts was significantly higher in young NZBxNZWF(1) mice than that in control (BALB/c and DBA/1) mice. Periductal laminin expression increased in NZBxNZWF(1)mice with age. In addition VLA-6, which is a ligand for laminin, was expressed by the infiltrating cells. These results suggest that laminin expression is associated with the cellular infiltration of the submandibular salivary gland of NZBxNZWF(1) mice.

Variation in the response to ductal obstruction of feline submandibular and sublingual salivary glands and the importance of the innervation

A variable response following ductal ligation of feline salivary glands corresponds to the human condition but contrasts with a predictable atrophy in obstructed salivary glands of rodents popularly used as a model for human salivary problems. The present investigation is concerned with a possible reason for the variable response, namely the preservation of the innervation. Ducts of feline submandibular and sublingual salivary glands were ligated with or without the inclusion of the chorda tympani. Inclusion led to a delayed initial response followed by progressive atrophy until the parenchyma was extremely atrophic, whereas avoidance of the chorda led to the variable response in which variable numbers of acini of a similar form to normal persisted. The results establish the atrophic effect of inclusion of the chorda tympani in ductal ligation and indicate the caution that should be exercised in the extrapolation of the rodent model to the human condition.

Cellular compartmentation of lysozyme and alpha-amylase in the mouse salivary glands. Immunogold approaches at light and electron microscopy level

The research was planned to study the subcellular distribution of enzymatic secretory products within the secretory structures of the mouse major salivary glands at light and electron microscopy level by immunogold silver stain (IGSS) technique and double-sided post-embedding immunogold binding and silver amplification in order to speculate about their compartmentation. In particular, we experimented the above immunogold labeling approaches to localize the lysozyme and to verify its distribution patterns in relation to another secretion enzyme, alpha-amylase. Co-presence of lysozyme and alpha-amylase was observed in the convoluted granular tubule cells of the submandibular gland and in the demilunar cells of the sublingual gland as well as in the electron-dense regions of the mottled secretory granules in the parotid gland. Exclusive binding patterns of lysozyme were observed in the acinar cells of the submandibular and sublingual glands where alpha-amylase did not occur.

Accumulation of common T cell clonotypes in the salivary glands of patients with human T lymphotropic virus type I-associated and idiopathic Sjögren's syndrome

To clarify the pathogenesis of human T lymphotropic virus type I (HTLV-I)-associated Sjögren's syndrome (SS), the TCR Vbeta gene usage by the infiltrating lymphocytes in the target organ was examined. The Vbeta families predominantly used in the labial salivary gland (LSG) from the HTLV-I-seropositive (HTLV-I+) SS patients were more restricted than those from the HTLV-I-seronegative (idiopathic) SS patients, and were commonly Vbeta5.2, Vbeta6, and Vbeta7. The single-strand conformation polymorphism analysis revealed that T cell clonotypes with Vbeta5.2, Vbeta6, and Vbeta7 accumulate in the LSG from the HTLV-I+ and idiopathic SS patients. Among junctional sequences of the most dominant Vbeta7 transcripts, the conserved amino acid motif (QDXG: X is any amino acid) was found in six of the five HTLV-I+ SS patients and was also detected in two of the five idiopathic SS patients. Using the probes specific to the motif, the Vbeta7 transcripts with the motif were detected in the LSG from all of the seven HTLV-I+ and five of the six idiopathic SS patients, but not from eight healthy subjects. The Vbeta7 transcripts with this motif were also detected in the HTLV-I-infected T cell lines obtained from the LSG of an HTLV-I+ SS patient. The accumulation of HTLV-I-infected T cells expressing TCR with the conserved motif was thus indicated. These T cells were commonly present in patients with idiopathic SS and are strongly suggested to most likely be involved in the pathogenesis of both HTLV-I-associated and idiopathic SS.

Endoscopic technique for the diagnosis and treatment of obstructive salivary gland diseases

PURPOSE

This article describes the use of endoscopy for diagnostic and surgical intervention in the major salivary glands of patients who have obstructive pathology, reviews past experience with this technique, and describes the microanatomy and pathophysiologic findings encountered during endoscopy of these glands.

PATIENTS AND METHODS

A total of 154 salivary glands (96 submandibular glands, 57 parotid glands, 1 sublingual gland) suspected of having obstructive pathology (89 males, 65 females; aged 5 to 72 years) were treated using a mini-endoscope. Most procedures were performed under local anesthesia in an outpatient clinic. All patients underwent preoperative and postoperative screening by routine radiography, sialography, and ultrasound. The indications for endoscopy were: 1) calculus removal that could not be performed by conventional methods, 2) screening of the salivary ductal system for residual calculi after sialolithotomy, 3) positive evidence of ductal dilatation or stenosis on the sialogram or ultrasound examination, and 4) recurrent episodes of major salivary gland swellings without known cause.

RESULTS

Of the 154 endoscopies performed, 9 were immediate failures as a result of technical problems. Of the remaining 145 glands, 112 had obstructions and 33 had sialadenitis alone. The success rate was 82% for calculus removal. Thirty-two percent of the submandibular and 63% of the parotid sialoliths, and the 1 stone in the Bartholin's duct, were undetected before sialoendoscopy. Multiple endoscopic findings were encountered. No major complications were noted.

CONCLUSIONS

Sialoendoscopy is a minimal invasive technique for the diagnosis and removal of obstructive pathologic tissue in the major salivary glands.