The impact of submandibular glands protection on xerostomia as monitored by diffusion-weighted imaging in nasopharyngeal carcinoma patients

PURPOSE

To determine the impact of sparing submandibular glands (SMGs) on alleviating xerostomia and the functional dynamics of the irradiated parotid glands (PGs) and sublingual glands (SLGs) by diffusion-weighted imaging.

METHODS

97 participants underwent 9 rounds of DWI scans before IC (pre-IC), pre-radiation (pre-RT), the midpoint of radiation (mid-RT), the end of radiation (post-RT), 1, 3, 6, 9, 12 (12m-RT) months following radiation. Apparent diffusion coefficient of SMGs (ADCSMG), PGs (ADCPG), and SLGs (ADCSLG), xerostomia questionnaire scores (XQ), and saliva flow rate measures under unstimulated (uSFR) and stimulated condition (sSFR) were documented.

RESULTS

ADCPG, ADCSMG, ADCSLG, and XQ showed a rapid increase with a top at 3m-RT followed by regression, whereas uSFR and sSFR had the reverse trend. The change rate of ADC correlated with the dose to PGs, SMGs, and SLGs, as well as uSFR, sSFR, and XQ scores (p < 0.05 for all, except for uSFR with ADCPG (p = 0.063)). Maingroup for ADCPG, uSFR, and sSFR were significant (p values were 0.028, 0.000, 0.000 respectively); ADCPG in SMG sparing group was lower while uSFR, and sSFR were higher than those in the SMG-unsparing group. Simplegroup for ADCSMG, ADCSLG (all p < 0.05 from mid-RT to 12m-RT), and XQ (all p < 0.001 at mid-, 6m-, 9m-, and 12m-RT) were significant; ADCSMG, ADCSLG, and XQ were lower in the SMG-sparing group.

CONCLUSIONS

SMG protection has a great impact on the functional retention of PGs and SLGs, resulting in alleviating xerostomia and improving quality of life.

TRIAL REGISTRATION

The clinical trial was also registered with the Chinese Clinical Study Registry (registered number: ChiCTR1900024328, Date: July 6, 2019; URL: https://www.chictr.org.cn/showproj.aspx?proj=40726 ).

Sublingual Gland Observed on Salivary Gland Scan

ABSTRACT

The major salivary glands, namely, the parotid, submandibular, and sublingual glands, are important in maintaining oral cavity health. A salivary gland scan is used to evaluate the uptake and excretory function of the salivary glands. By intravenously injecting 99m TcO 4- , which is distributed like chloride ions in the body, the glands become visible on the salivary gland scan. The parotid and submandibular glands are typically appreciated on the salivary gland scan, but the sublingual gland is not. We present a rare image of a prominent sublingual gland on a salivary gland scan.

Plunging Ranulas and Prevalence of the "Tail Sign" in 126 Consecutive Cases

OBJECTIVES

Plunging (or diving) ranulas are extravasation pseudocysts arising from the sublingual gland that present as soft submandibular swelling. The "tail sign" has been widely reported as pathognomonic for their diagnosis. It is described as a smooth tapering comet-shaped unilocular fluid mass with its "tail" in the collapsed sublingual space (SLS) and its "head" in the posterior submandibular space. This sign is based on the premise that extravasated saliva from the sublingual gland in the SLS escapes and plunges, over the posterior edge of the mylohyoid muscle into the submandibular space. Therefore, some fluid must be present in the posterior SLS in almost all patients with plunging ranulas. This study aimed to determine the frequency of fluid seen with ultrasound (US) in the posterior SLS to corroborate the tail sign.

METHODS

A total of 126 consecutive cases of surgically proven plunging ranulas were investigated with US over 13 years. The findings were reviewed retrospectively for the prevalence of fluid in the posterior SLS.

RESULTS

Thirteen patients (10.3%) showed SLS fluid on US images. Most showed fluid extension through a mylohyoid dehiscence. Only 2 patients (1.6%) showed fluid within the posterior SLS, and 1 patient alone in this entire study showed all of the components of the classically described tail sign.

CONCLUSIONS

This largest ever radiologic study showed low prevalence of the tail sign in 2 of 126 patients. A mylohyoid dehiscence was the more common route for extravasation. Absence of the tail sign does not exclude the diagnosis of a plunging ranula.

Differentiation of sublingual thyroglossal duct cyst from midline dermoid cyst with diffusion weighted imaging

PURPOSE

to differentiate sublingual thyroglossal duct cyst (TGDC) from midline dermoid cyst (DC) with diffusion weighted imaging (DWI).

MATERIALS AND METHODS

Retrospective analysis of 22 consecutive patients (11 male and 11 female aged 5-15 years) with midline cystic lesion at floor of mouth. They underwent DWI of floor of mouth. Apparent diffusion coefficient (ADC) of the cystic lesions was calculated and correlated with surgical findings.

RESULTS

The mean ADC value of TGDC of 1st observer was (2.20 ± 0.28 × 10^-3 mm²/s) and of 2nd observer was (2.28 ± 0.27 × 10^-3 mm²/s) was significantly higher than that of DC (P = 0.001) whose ADC of 1st observer was (1.55 ± 0.15 × 10^-3 mm²/s) and of 2nd observer was (1.53 ± 0.11 × 10^-3 mm²/s). There was excellent inter-observer agreement of both readings (r = 92%, P = 0.001). When ADC of 1.76 and 1.62 × 10^-3 mm²/s was used as a threshold value for differentiating TGDC from DC, the best results were obtained with area under the curve of 0.94 and 0.96, accuracy of 90% and 86%, sensitivity of 91% and 91%%, specificity of 90% and 80%, negative predictive value of 90% and 88% and positive predictive value of 92% and 84% of both reviewers respectively.

CONCLUSION

DWI is reliable and reproducible imaging modality for differentiation sublingual TGDC from DC.

Sublingual gland excision for the surgical management of plunging ranula

OBJECTIVE

A plunging ranula is a pseudocystic collection of mucin extravasated from the sublingual gland into the floor of mouth and through the mylohyoid muscle into the neck. While the lining of a ranula is non-secreting and resection of the sublingual gland is adequate for simple sublingual mucoceles, many surgeons attempt to address plunging ranulas with extensive transoral and transcervical dissections. We review our experience managing plunging ranulas with intraoral sublingual gland excision and ranula drainage alone.

METHODS

This is a case series of patients with plunging ranulas who underwent transoral sublingual gland excision and ranula drainage in the past 10 years at the Massachusetts Eye and Ear. All ranulas were confirmed by radiographic imaging. Data were gathered from the medical record and telephone surveys.

RESULTS

Twenty-one patients with 22 distinct ranulas underwent this surgical approach. Average ranula size on imaging was 4.3 cm (SD = 1.3). Thirteen patients with 14 ranulas were followed up for greater than 6 months while the remaining 7 patients were lost to follow-up. Median follow-up for the 13 patients was 30 months (range 6 to 80). One ranula recurred requiring excision of residual sublingual gland (7%). One patient developed a local infection that was treated with antibiotics (7%). No long term complications were reported.

CONCLUSION

Simple transoral excision of the sublingual gland with ranula drainage is sufficient for treatment of plunging ranulas. It is essential to obtain a full resection of the gland to prevent relapse. This limited approach has low rates of complications and ranula recurrence.

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.

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.

Bilateral plunging ranula: two case reports and a review of the literature

AIM

Presentation of two bilateral plunging ranula cases and then review of the plunging ranula literature to understand current concepts on aetiology, imaging for diagnosis and management.

METHOD

A literature review using PubMed (92 papers) and Google Scholar (18 papers) has revealed only 18 cases of bilateral plunging ranulas ever published and with the addition of the two cases presented this makes a total of 20.

RESULTS

These cases are reviewed and information related to aetiology and management is presented. The cause appears to be a combination of mylohyoid dehiscence, racial predisposition and previous trauma to the mouth/face or previous oral surgery.

CONCLUSION

Plunging ranula are a rare cause of bilateral and unilateral neck swellings but more common in Maori, Polynesian and Asian people. Their cause is multifactorial and ultrasound scan (USS) is the current investigation of choice. Management relies on excision of the sublingual gland with the cystic contents via a trans-oral approach.

[Sublingual gland amyloidosis causing obstructive sleep apnea hypopnea syndrome: a case report and review of the literatures]

OBJECTIVE

To improve the understanding of sublingual gland amyloidosis causing obstructive sleep apnea hypopnea syndrome(OSAHS).

METHODS

A case of sublingual gland amyloidosis causing OSAHS diagnosed in april 2012 was reported and the related literatures were reviewed. The literature review was carried out respectively with "amyloidosis, sublingual gland, obstructive sleep apnea hypopnea syndrome", as the search terms in Wanfang Data and PubMed by November 2012.

RESULTS

A case of 74 year-old male patient was admitted to the hospital because of snoring for 5 years, sleep apnea for 1 year and arousal for 1 month. After admission, polysomnography showed severe OSAHS, physical examination showed redundant the sublingual gland. Enhanced CT scanning showed soft tissue masses at the sublingual gland. Abdominal B ultrasonic and CT also showed a spaces-occupying lesion in the left retroperitoneal. B-guided core needle biopsy was performed in the left retroperitoneal. Pathology report showed amyloidosis. Subsequently, sublingual gland mass resection was performed. Pathology report after operation showed amyloid deposits staining with Congo red, which gives it a characteristic green birefringence in polarised light. Accordingly, it was diagnosed as sublingual gland amyloidosis. The symptoms of snore and sleep apnea were disappeared after operation.So far, there was no local recurrence with 10 months follow-up. A total of 3 literatures were received in Wanfang Data, including 2 of macroglossia amyloidosis causeing OSAHS case report and one of retrospective study. There were no reports about sublingual gland amyloidosis in Wanfang Data. A total of 5 literatures were received in Pubmed, including 2 of sublingual gland amyloidosis case report, 2 of macroglossia amyloidosis causeing OSAHS case report and one of retrospective study. However, there were no reports about sublingual gland amyloidosis causing OSAHS.

CONCLUSIONS

Amyloidosis rarely occurred in the sublingual gland and is easy to be misdiagnosed and missed diagnosed, which can causing severe OSAHS. To make a definite diagnosis, histopathology and staining with Congo red are needed and a characteristic green birefringence in polarised light is a reliable marker for diagnosis. After sublingual gland mass resection, the patient had good prognosis.

Anterior lingual mandibular bone depression in an 11-year-old child

This report describes physical and imaging findings in a case of anterior lingual mandibular bone depression in a child. This entity is very rarely diagnosed and even more extremely rarely seen in children. We present some characteristic findings depicted on images provided by different sources and briefly address current hypotheses on its pathogenesis.

Plunging ranula

Plunging ranulas are rare cystic masses in the neck that are mucous retention pseudocysts from an obstructed sublingual gland. They "plunge" by extending inferiorly beyond the free edge of the mylohyoid muscle, or through a dehiscence of the muscle itself, to enter the submandibular space. Imaging demonstrates a simple cystic lesion in the characteristic location and can be used to delineate relevant surgical anatomy. Surgical excision of the collection and the involved sublingual gland is performed for definitive treatment. We present a case of plunging ranula in a 44 year old female who presented with a painless, slowly enlarged neck mass. Plunging ranulas should be considered in the differential diagnosis of cystic neck masses, specifically when seen extending over, or through, the mylohyoid muscle.

Scintigraphic assessment of salivary gland function in a rat model

BACKGROUND

Salivary gland dysfunction with xerostomia is a major clinical problem without a causal therapy in most cases. The development of an animal model for scintigraphic assessment of salivary gland function has great clinical relevance for the investigation of promising new diagnostic and therapeutic strategies for chronic salivary gland diseases. This study reports the first experiences with scintigraphic analyses of salivary gland function in a rat model.

MATERIALS AND METHODS

Anatomical and scintigraphic studies were performed for topographic differentiation of major salivary glands of Wistar rats. (⁹⁹m)technetium pertechnetate salivary gland scanning was performed, appropriate regions of interest were determined and the gland-to-background ratio was examined for the evaluation of salivary gland function.

RESULTS

The quantitative analysis of salivary gland scintigraphy revealed a reliable comparison of major salivary glands on both sides with the gland-to-background ratio ranging from 1.26 to 1.94 with an average of 1.51.

CONCLUSION

This model seems to be appropriate for functional studies in an experimental setting.

Sublingual gland sialolithiasis: a case report

Sublingual gland sialolithiasis is rare and may be misdiagnosed as submandibular gland sialolithiasis, which is more common. It is important to preoperatively determine which gland is involved, because they require different surgical approaches. Computed tomography (CT) is useful for distinguishing between sublingual gland and submandibular gland sialolithiasis. In this paper, we report the case of a 50-year-old man with left sublingual gland sialolithiasis that was treated with excision of the left sublingual gland and the stone via a transoral approach, 6 weeks after the infection was controlled. The differential diagnosis between sublingual gland and submandibular gland sialolithiases, by use of CT images, is discussed from an anatomic viewpoint.

Unilateral submandibular gland aplasia associated with ipsilateral sublingual gland hypertrophy

Congenital absence of the major salivary glands is an infrequent disorder. Clinically, patients may be asymptomatic or may present with dryness of the mouth, difficulty in chewing and swallowing, and dental caries. The absence of the submandibular gland may be associated with hypertrophy of the contralateral submandibular gland. We report a case of ipsilateral sublingual hypertrophy associated with unilateral submandibular aplasia.

A diagnostic challenge: anterior variant of mandibular lingual bone depression

Mandibular lingual bone depressions are considered to be developmental anomalies and most clinicians are familiar with the posterior variant (known as Stafne's bone cavity) that occurs in lingual mandibular molar regions, adjacent to the submandibular gland and below the mandibular canal. The anterior variant of the mandibular lingual bone depression is an asymptomatic bone cavity that occurs adjacent to the sublingual gland in the anterior mandible. Radiographically, it appears as a well-corticated radiolucency that retains a normal trabecular pattern internally. CT imaging is diagnostic and avoids surgical and sialographic procedures. This article reviews radiographic and CT features of a case involving the anterior variant of mandibular lingual bone depression.

Solitary fibrous tumor with pseudo-lipoblasts involving the sublingual gland: report of a case and review of the literature

Solitary fibrous tumors (SFTs) are mesenchymal neoplasms uncommonly occurring in the salivary glands. In rare instances, SFTs can contain mature fat, atrophic fat, or vacuolated cells previously termed 'pseudo-lipoblasts', which may be misinterpreted as a feature of malignancy. We report an unusual tumor with pseudo-lipoblasts occurring in the sublingual gland. The tumor exhibited a prominent hemangiopericytic pattern, bland cytology, and immunohistochemical and morphologic features consistent with that of an SFT. A review of 15 cases of SFTs of the salivary glands is presented. Emphasis is laid upon the histologic differential diagnosis and the clinical features of these tumors.

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.

Two cases of plunging ranula managed by the intraoral approach

Two cases of plunging ranula are reported. Treatment consisted of the total removal of the sublingual gland and evacuation of the cystic contents by the intraoral approach. The cyst remained just after the surgery in both cases, but then gradually regressed and disappeared within two months after the surgery. These findings support total removal of the sublingual gland as being the best method of treatment. We believe that complete dissection of the cyst with cervical incision as well as drainage of the cystic contents are unnecessary when the diagnosis of the plunging ranula is confirmed.

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.

[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.

Plunging ranula: clinical observations

BACKGROUND

The plunging ranula is a relatively uncommon phenomenon which represents a mucus escape reaction occurring from disruption of the sublingual salivary gland. We present a series of 20 patients managed at Green Lane Hospital (Auckland, New Zealand) over a 9-year period.

METHODS

A retrospective review of 13 patients with this condition was undertaken, and a prospective study was conducted on 7 patients. Information was collected on age, sex, ethnic origin, history of onset, predisposing factors, treatment, and outcome of treatment.

RESULTS

The patients were all young adults with a median age of 31 years. The sex distribution was relatively equal, with 11 men and 9 women. All patients were Maori or Pacific Island Polynesians. Six patients gave a clear history of preceding trauma to the neck or oral cavity. Two recurrences were seen, both in patients who had had the sublingual gland excised via a cervical approach. Five patients sustained lingual nerve damage during surgery. Full function recovered in four patients, but the complication was still present in the fifth patient at 2 years, after which he was lost to follow-up.

CONCLUSIONS

Plunging ranulas appear to occur with greater incidence in the Maori and Pacific Island Polynesian populations. The precise etiology of their predisposition is unknown, although local trauma or inherent mylohyoid dehiscences may play important roles. Removal of the sublingual gland via either a cervical or intraoral approach is important in the management of this condition. Excision of the pseudocyst is probably unnecessary and places surrounding structures at risk of damage, but a biopsy of the pseudocyst wall is important to confirm the diagnosis.

CT scanning of the plunging ranula. Case report

A diagnosis of the deep plunging ranula usually is based upon the history and clinical examination of the patient. The case presented here highlights the role of the CT scan in facilitating a definitive diagnosis. Visualization of the anatomic relations of the accumulated secretion, as it dissects its way through the cervical tissue planes, also is made possible.

Ultrasonography of the sublingual space

Fifty-three patients were evaluated by ultrasonographic visualization of the sublingual space as part of routine neck sonography. Delineation of the sublingual gland was good or fair in 93% of the cases. The normal gland was 32.06 mm long in the sagittal plane. The submandibular duct was identified in 53% of the cases and measured less than 2.5 mm in diameter. The sublingual vessels were detected in 93% of the cases and had almost the same mean diameter as the duct. Four cases of frequent pathologies in this region were also examined. Ultrasonography is the examination to use for diseases of the sublingual space.

Dosimetry of absorbed radiation in radiographic cephalometry

Absorbed radiation was measured in various craniofacial tissues on an adult phantom (Alderson Rando) when conventional cephalometric radiographic techniques were used. The views examined were lateral, 45 degrees oblique, posteroanterior, lateral temporomandibular joint tomograph, and basilar (submental-vertex). Absorbed radiation was expressed in micrograys for the individual views and for combinations of views as customarily used in orthodontics and oral surgery. These data are compared with findings of contemporary investigators and the magnitude of the doses is compared with those in the literature for periapical and panoramic surveys.

Salivary gland 99mTc-scintigraphy: a grading scale and correlation with major salivary gland flow rates

Sequential salivary gland scintigraphy with 99mTc-technetium pertechnetate (Tc-99) is a safe, minimally invasive test for study of major salivary glands. However, its relationship to salivary function has not been investigated in detail. We have investigated the relationship between major salivary gland flow rates and Tc-99 scans and developed a new rating scale using scans of a control group with normal salivary function. Salivary flow rates and Tc-99 scans were obtained from healthy, non-medicated subjects (n = 33) and from xerostomic patients (n = 22). There were significant differences between the groups for salivary flow rates and Tc-99 ratings. Significant correlations were found between salivary flow rates and Tc-99 ratings in the control and xerostomic groups. The Tc-99 rating scale proved reliable in assessing salivary dysfunction, and showed a high inter-examiner correlation. These results demonstrate the usefulness of salivary gland scintigraphy in assessing major salivary gland flow rates and the utility of a new rating scale.

Absorbed dose to organs in the head and neck from bitewing radiography

Dose measurements were carried out to estimate the absorbed dose to organs at risk from bitewing radiography under exposure conditions similar to those found in general dental practice in The Netherlands. The measurements were carried out in the head and neck of a Rando phantom using TLD-100 ribbons. Three different X-ray machines were used simulating 10 different exposure conditions to determine the effects of beam energy, beam size and focus-skin distance on the absorbed dose. The absorbed dose in the primary beam, close to the focal spot, decreased as the beam energy increased, while behind the film plane it increased with the beam energy. Outside the primary beam, at short distances from the skin surface, the absorbed dose decreased as the energy increased, while behind the film plane and at greater distances from the primary beam the absorbed dose increased as the beam energy increased. The absorbed dose was significantly lower for smaller beam sizes and for larger focus-skin distances, independent of beam energy.

Ranulas and their mimics: CT evaluation

The spectrum of computed tomographic (CT) findings in ten patients with pathologically proved simple and diving ranulas is reviewed. These retention cysts originate within the sublingual space from obstruction of the sublingual or minor salivary glands; when they enlarge, the cysts herniate to involve the submandibular and inferior parapharyngeal spaces (the so-called diving or plunging ranula). CT findings in 38 additional patients with a variety of cystic lesions in the floor of the mouth are contrasted with findings in cases of ranulas. The relevant anatomy is reviewed. This experience indicates that a unilocular, cystic mass emanating from the sublingual space and extending into the adjacent submandibular and/or inferior parapharyngeal spaces can be considered a diving ranula in virtually all cases. A unilocular, cystic mass entirely within the sublingual space can be considered a simple ranula in most instances, although absolute distinction between a simple ranula and an epidermoid cyst cannot be made radiographically.

[Results of sialography (author's transl)]

A randomly selected group of patients which had been subjected to sialography during 1975/76, was analysed retrospectively. In a total of 386 patients, 395 contrast radiographs had been performed; of these, 243 sialographs were evaluated retrospectively, the definite diagnosis having been established by surgery, biopsy or clinical course of the disease. The accuracy of diagnosis was 95% when employing diagnosis by exclusion (sialographic diagnosis having yielded "normal findings"), the correct diagnosis being the presence of concrements and inflammatory diseases of the salivary gland. However, the rate of error amounting to 5% must be considered a cause for concern insofar as of the total of 8 wrong diagnoses (against a total of 154 correct diagnoses), 7 patients had tumours which had not been recognized, four of these tumours being of a malignant nature. The presence of a space-occupying process was diagnosed with an accuracy of 88%. Space-requiring growths, provided they were properly diagnosed, were correctly localised in 83% of the cases. Statements on the degree of malignancy of a tumour--which were made in about one-third of the tumour diagnoses only--were found to be correct in 83% of the cases. False positive findings were obtained in 12% of the patients.

Sublingual sialography

A case of specific catheterization of the sublingual gland is presented. The possibility of routine examination of this gland is discussed on the basis of a review of the literature.