Mylohyoid herniation of the sublingual gland diagnosed by magnetic resonance imaging

Imaging of salivary gland cancers derived from a sublingual gland herniated into the submandibular space: a report of three cases

Sublingual gland herniation into the submandibular space through a mylohyoid muscle defect is a common anatomical variation; however, salivary gland cancers that arise from a herniated sublingual gland have not been described yet. Here, we report three patients with salivary gland cancers originating from a herniated sublingual gland. All tumors were detected as palpable submandibular masses, located anterior to the submandibular gland, medial to the mandible, and lateral to the mylohyoid muscle, with contact with the sublingual gland through a mylohyoid muscle defect. Intraoperative findings confirmed that the masses were derived from herniated sublingual glands. Pathological examination showed one case of mucoepidermoid carcinoma and two cases of adenoid cystic carcinoma. Imaging findings of the tumor location, in addition to the continuity with the sublingual gland through the mylohyoid muscle defect, are crucial for accurately diagnosing the tumor origin, which is essential for determining the appropriate clinical management.

Submandibular swelling, pulsations and otalgia due to sublingual gland and blood vessels herniation through mylohyoid boutonnière: Case report

Background/Aim: Mylohyoid boutonnière is a common anatomical variant with extremely rare clinical manifestations. We report two cases of symptomatic unilateral mylohyoid boutonnière with sublingual gland herniation. Case report: The first was a 34-year-old female with a two months history of a left submandibular swelling, intermittent pulsations, and otalgia. The second 67-year-old female presented with a left submandibular pain six months after total thyroidectomy due to papillary carcinoma. After detailed clinical and radiological evaluation by ultrasonography (US) and computed tomography (CT), the mylohyoid gap with sublingual gland herniation was diagnosed in both patients. The dynamic US with a tongue pressed down on the mouth floor revealed blood vessel compression by a herniated sublingual gland in the first patient. Conclusions: This is the first case of a mylohyoid boutonnière related intermittent vascular compression. Dynamic US and CT may help to differentiate intermittent and persistent sublingual gland herniation through the mylohyoid boutonnière from other pathological lesions in the submandibular region.

Unilateral sublingual salivary gland hypertrophy with herniation through a boutonniére defect and contralateral sublingual gland hypoplasia

A 74-year-old male attended our ear, nose and throat clinic with left-sided otalgia. MRI highlighted an area of abnormal signal in the region of the right mylohyoid muscle in the floor of the oral cavity. The patient was called back for a post-contrast MRI scan for clarification. Post-contrast MRI demonstrated a left-sided hypoplastic sublingual salivary gland and a hypertrophied right-sided sublingual salivary gland. The left sublingual gland hypoplasia had resulted in compensatory hypertrophy of the contralateral (right) sublingual salivary gland, extending through the mylohyoid gap or "boutonnière defect". This is a common incidental variant often encountered in radiological imaging. This is the only report of a case of contralateral compensatory hypertrophy of sublingual salivary gland, as all the others have reported ipsilateral hypertrophy of either submandibular salivary glands.

Are the patients with anatomic variation of the sublingual/Wharton's duct system predisposed to ranula formation?

OBJECTIVE

To evaluate ranula development according to anatomic variation of the ductal system of sublingual gland (SLG), especially the presence of Bartholin's duct.

METHODS

The anatomic variation of SLG duct was prospectively investigated and compared between 55 consecutive patients with ranulas treated by SLG excision (group 1) and another 15 consecutive patients undergoing similar surgeries for other conditions (group 2). The ductal structures of SLGs and submandibular glands (SMG) were also compared between the pediatric patients and adult patients with ranulas.

RESULTS

In 32 of 55 patients with ranulas (58.2%) and 1 of 15 patients without ranulas (6.7%), the SLG showed an anatomic variation of the main duct called Bartholin's duct structure (P<0.01). Seventeen of 22 (77.3%) pediatric patients with ranulas had Bartholin's ducts and 15 of 33 (45.5%) adult patients with ranulas had Bartholin's ducts (0.01<P<0.05), but Bartholin's duct which opens near to the orifice of Wharton's duct was not found in this study population. Plunging ranulas that extravasate deep to the mylohyoid were observed in the 6 patients (4 children and 2 adults). There was no recurrence in all cases with ranulas.

CONCLUSIONS

Congenital anatomic variation of the ductal system of the SLG might be a possible cause of ranulas in the patients with simple ranulas, especially in pediatric patients. Surgical resection of the SLG is a better treatment choice for ranulas than other conservative treatments.

Plunging Ranulas Revisited: A CT Study with Emphasis on a Defect of the Mylohyoid Muscle as the Primary Route of Lesion Propagation

Objective

The purpose of this study was to clarify the pathogenesis of plunging ranulas in regard of the pathway of lesion propagation using CT scans.

Materials and Methods

We retrospectively reviewed CT scans of 41 patients with plunging ranula. We divided plunging ranulas into two types: type 1 was defined as those directly passing through a defect of the mylohyoid muscle with the presence (type 1A) or absence (type 1B) of the tail sign and type 2 as those through the traditional posterior route along the free edge of the mylohyoid muscle. Images were also analyzed for the extent of the lesion in respect to the spaces involved. As for type 1 lesions, we recorded the location of the defect of the mylohyoid muscle and the position of the sublingual gland in relation to the defect.

Results

CT scans demonstrated type 1 lesion in 36 (88%), including type 1A in 14 and type 1B in 22, and type 2 lesion in 5 (12%). Irrespective of the type, the submandibular space was seen to be involved in all cases either alone or in combination with one or more adjacent spaces. Of the 36 patients with type 1 lesions, the anterior one-third was the most common location of the defect of the mylohyoid muscle, seen in 22 patients. The sublingual gland partially herniated in 30 patients.

Conclusion

Our results suggest that the majority of plunging ranulas take an anterior shortcut through a defect of the mylohyoid muscle.

Salivary gland diseases in children

Salivary gland diseases in children are rare, apart from viral-induced diseases. Nevertheless, it is essential for the otolaryngologist to recognize these uncommon findings in children and adolescents and to diagnose and initiate the proper treatment.

The present work provides an overview of the entire spectrum of congenital and acquired diseases of the salivary glands in childhood and adolescence. The current literature was reviewed and the results discussed and summarized.

Besides congenital diseases of the salivary glands in children, the main etiologies of viral and bacterial infections, autoimmune diseases and tumors of the salivary glands were considered. In addition to the known facts, new developments in diagnostics, imaging and therapy, including sialendoscopy in obstructive diseases and chronic recurrent juvenile sialadenitis were taken into account. In addition, systemic causes of salivary gland swelling and the treatment of sialorrhoea were discussed. Although salivary gland diseases in children are usually included in the pathology of the adult, they differ in their incidence and some­times in their symptoms. Clinical diagnostics and especially the surgical treatment are influenced by a stringent indications and a less invasive strategy. Due to the rarity of tumors of the salivary glands in children, it is recommended to treat them in a specialized center with greater surgical experience.

Altogether the knowledge of the differential diagnoses in salivary gland diseases in children is important for otolaryngologists, to indicate the proper therapeutic approach.

Dynamic sonography and CT findings of unilateral submandibular gland agenesis associated with herniated hypertrophic sublingual gland

Congenital agenesis of the submandibular gland is uncommon. We report dynamic sonography and CT findings of the unilateral submandibular gland agenesis associated with herniated hypertrophic sublingual gland tissue through the mylohyoid gap. The dynamic sonography examination applied at rest and during the modified Valsalva maneuver demonstrated hypertrophied sublingual gland prolapsing to the anterior part through the mylohyoid gap. This may be the first reported case describing dynamic sonography findings of this entity. CT confirmed the agenesis of the left submandibular gland and compensatory hypertrophy of the ipsilateral sublingual gland.

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.

Management of ranula: 9 years' clinical experience in pediatric and adult patients

PURPOSE

The aim of the present study was to evaluate the long-term results in the authors' department in the management of patients with oral and plunging ranulas. A specific diagnostic and therapeutic approach is suggested based on these data and data from the literature.

MATERIALS AND METHODS

A retrospective analysis of 65 patients with a final diagnosis of ranula was carried out. The medical records were evaluated for the principal demographic, clinical, diagnostic, and therapeutic data. Statistical analysis was used to compare outcomes of the different treatments.

RESULTS

Treatments that included complete sublingual gland excision were associated with the lowest recurrence rate (3.6%), followed by partial sublingual gland excision (9.1%), marsupialization (13%), and ranula excision (36.7%). Nine patients (13.8%) had recurrences. A statistically significant difference was observed (P = .01) in the recurrence rate between complete sublingual gland excision and ranula excision alone. Complications developed in 7 patients (10.8%). Ultrasonography performed in all patients showed an intimate relation among the cyst, mylohyoid muscle, and sublingual gland. Dehiscence of the mylohyoid muscle was noted in some cases.

CONCLUSIONS

The surgical experience in the authors' department confirms the different treatments that are offered for ranula. Sublingual gland excision should be the preferred treatment, but marsupialization may be useful as an alternative minimally invasive procedure, with a success rate higher than 85% and no risk of increased complications if revision surgery is needed. Ultrasound is the recommended diagnostic tool, in addition to the clinical examination, for the differential diagnosis and during follow-up.

Imaging the oral cavity: key concepts for the radiologist

The oral cavity is a challenging area for radiological diagnosis. Soft-tissue, glandular structures and osseous relations are in close proximity and a sound understanding of radiological anatomy and common pathways of disease spread is required. In this pictorial review we present the anatomical and pathological concepts of the oral cavity with emphasis on the complementary nature of diagnostic imaging modalities.

Surgery for plunging ranula: the lesson not yet learned?

Our objective is to review our experience with treatment of plunging ranula and examine the efficacy of transoral excision of sublingual gland as the principal treatment. This study comprises a case series with chart review. A secondary otolaryngology service was used as the setting. Retrospective analysis of patient records was performed for a series of 95 consecutive cases of plunging ranula, which presented to our department between January 2001 and February 2010. Clinical presentation, investigations, diagnosis, treatment, complications and outcome were recorded. Literature search was performed using MEDLINE and OLD MEDLINE. 81 cases of plunging ranula were treated surgically by transoral excision of sublingual gland and evacuation of ranula contents. Mean operating time was 75.3 min. Twelve patients had undergone previous surgery elsewhere. One patient in our series had a recurrence, needing excision of sublingual gland remnant. Two patients had trauma to submandibular duct requiring excision of submandibular gland. Other complications were minor and transient. Review of literature revealed many diverse methods of treating ranula, with varying results. Our series makes a substantial contribution to the number of plunging ranulas reported in the world, and supports the use of transoral sublingual gland excision as first-line treatment of plunging ranula.

Imaging of the mylohyoid muscle: separation of submandibular and sublingual spaces

OBJECTIVE

This article focuses on the anatomy of the mylohyoid muscle, a crucial landmark in imaging of the oral cavity and upper neck, showing dissected specimens and CT and MR images.

CONCLUSION

Identification of the relationship of a lesion in the sublingual space to the mylohyoid muscle using MDCT and high-resolution MRI is a key part of the imaging assessment of the oral cavity and upper neck.

Plunging Ranula: Congenital or Acquired?

OBJECTIVE: To review our clinical experience with plunging ranula and examine the evidence in support of our impression that plunging ranula has a genetic basis.

STUDY DESIGN: Case series with chart review.

SETTING: Secondary otolaryngology service.

SUBJECTS AND METHODS: Review of the medical records of a clinical series of 80 consecutive plunging ranulas in 77 patients was conducted, with recording of clinical and radiological findings, surgical treatment, and outcome. A literature review using MEDLINE and OLD MEDLINE was performed.

RESULTS: The majority of plunging ranulas had no intraoral component on clinical examination, although evidence of mucus extravasation from the sublingual gland could be found both radiologically and histologically in all cases. There were four patients with bilateral plunging ranula and one instance of siblings with unilateral plunging ranula. Maoris and Polynesians comprised more than 82 percent of our cases; this was a significant overrepresentation of these ethnic groups ( P < 0.0001). A very strong predominance of cases of Chinese origin was also evident in the literature.

CONCLUSION: The clinical findings and the supporting data from the literature, when viewed in light of information relating to the known anatomical anomaly of a dehiscence in the mylohyoid muscle and ectopic sublingual gland lying below the plane of the mylohyoid, appear to support the case for a genetic basis for this unusual clinical entity.

Plunging ranulas: high-resolution ultrasound for diagnosis and surgical management

OBJECTIVES

We see a high incidence of plunging ranulas, particularly in Maori and Polynesian populations. We have investigated the usefulness of ultrasound in the diagnosis and management of plunging ranulas and present our findings.

METHODS

Thirty-three new cases were examined over 4 years (June 2004 to October 2008).

RESULTS

High-resolution ultrasound was very successful in determining the extent of the plunging ranula, confirming the cystic nature of the lesion, assessing the status of the mylohyoid muscle (a defect demonstrated in 100% of our cases) and evaluating the sublingual gland for rupture or herniation. Correlation with surgical findings was available for 30 cases. There was excellent ultrasonographic and surgical correlation, particularly with respect to submandibular space cystic collection (29 of 30 cases, 96.7%) and mylohyoid defects (27 of 30 cases, 90%).

CONCLUSIONS

With the considerations of cost, accessibility and the fact that many of our patients are young (median of 20 years), ultrasound is recommended as the preferred examination for plunging ranula.

Incidence and clinical relevance of herniation of the mylohyoid muscle with penetration of the sublingual gland

Swelling of the submandibular region may cause problems in daily clinical diagnosis and requires further exploration. Ultrasonic examination provides a simple, non-invasive and radiation-free method. The goal of our study was to show the high incidence of herniation of the mylohyoid muscle with penetration of the sublingual glands, in some cases clinically imposing as permanent swelling. Penetration was classified into four grades (Grade 0-III). In course of routine examinations of the neck by ultrasound, the anterior part of the mylohyoid muscle was observed in 124 consecutive patients from our outpatient's clinic, presenting with unclear swelling of the neck, mostly due to lymph nodes. In resting position and during swallowing the degree of penetration of the sublingual gland through the mylohyoid muscle was staged. Almost 60% of patients showed an affection of the mylohyoid muscle at either site of varying degrees. In 40% only a thinning of the muscle could be noticed (grade I), whereas in 21 patients (17%) a significant herniation of the gland during swallowing could be observed (grade II). In two patients (2%) a constant breach of the mylohyoid muscle with permanent herniation of the gland imposing as swelling could be seen (grade III). Occasional or permanent penetration of the sublingual gland through the mylohyoid muscle is not a rare finding and can be found in almost every fifth individual using ultrasound. This may impose clinically as permanent swelling and may be of value in the differential diagnosis of swelling in the submandibular region.