MR imaging of squamous cell carcinoma of the floor of the mouth. Appearance of the sublingual and submandibular glands.

PURPOSE: To determine the diagnostic value of MR imaging for tumors of the floor of the mouth and the effects of the tumors on the sublingual and submandibular glands. MATERIAL AND METHODS: Thirty-seven patients with proven squamous cell carcinoma of the floor of the mouth underwent MR imaging, including unenhanced T1-weighted, T2-weighted, dynamic, and contrast-enhanced T1-weighted images. The appearance of the tumor and the sublingual and submandibular glands was assessed qualitatively and quantitatively. RESULTS: All tumors demonstrated replacement of the normal signal intensity in the adjacent sublingual gland. Twenty-one patients (57%) had abnormal signal intensity of the submandibular gland without tumor invasion, presumably secondary to submandibular duct obstruction by the tumor. Unenhanced T1-weighted images provided high contrast between tumor and sublingual gland. Tumors limited within the gland were well detected on unenhanced T1-weighted images. Large tumors extending beyond the gland were well delineated on dynamic images, but no better than on T2-weighted images. CONCLUSION: At MR imaging for tumor of the floor of the mouth, one must carefully evaluate the appearance of the sublingual and submandibular glands. Contrast-enhanced studies are unnecessary when the tumor is limited within the sublingual gland on precontrast MR images.     

Schwannoma in the sublingual space

In this report, we present CT and MRI findings of a case of a schwannoma that developed in the floor of the oral cavity. A 49-year-old woman visited our hospital with a painless swelling in the oral floor. CT and MRI revealed a well circumscribed oval mass in the sublingual space, which showed cystic degeneration in most of the lesion. In addition, a thickened wall that strongly enhanced after injection of contrast medium and formation of fluid level were observed in the mass. The mass was removed and was histopathologically diagnosed as schwannoma. Only a few cases of schwannoma in the oral floor have been reported. However, when the characteristic findings are observed on CT and MRI, schwannoma should be added to the differential diagnosis.     

MRI of the floor of the mouth, tongue and orohypopharynx

Magnetic resonance is the imaging modality of choice for studies of the orohypopharynx, floor of the mouth, or tongue base. The superiority of MRI soft tissue contrast can demonstrate intra- and extraorgan spread of tumor beyond that of CT. Use of T1- and T2-weighted pulse sequences allows better discrimination of pathologic masses from fat or muscle than does CT. Multiplanar capabilities allow ease of examination in the preferred planes. Various sequences or planes of imaging may be chosen to tailor the examination to the anatomic region of interest. The use of Gd-DTPA with T1-weighted images should further improve diagnostic precision of tumor location and extension and may replace the need for the longer T2-weighted sequences. Gadolinium may help differentiate tumor recurrence from fibrosis in the post-radiation patient. New improvements in surface coil technology, motion and flow compensation imaging strategies, faster scan times, and spatial resolution will further advance MRI as the modality of choice for assessment of oropharyngeal, mouth, and tongue soft tissue masses.     

Imaging of the posterior pelvic floor

Disorders of the posterior pelvic floor are relatively common. The role of imaging in this field is increasing, especially in constipation, prolapse and anal incontinence, and currently imaging is an integral part of the investigation of these pelvic floor disorders. Evacuation proctography provides both structural and functional information for rectal voiding and prolapse. Dynamic MRI may be a valuable alternative as the pelvic floor muscles are visualised, and it is currently under evaluation. Endoluminal imaging is important in the management of anal incontinence. Both endosonography and endoanal MRI can be used for detection of anal sphincter defects. Endoanal MRI has the advantage of simultaneously evaluating external sphincter atrophy, which is an important predictive factor for the outcome of sphincter repair. Many aspects of constipation and prolapse remain incompletely understood and treatment is partly empirical; however, imaging has a central role in management to place patients into treatment-defined groups.     

Normal CT anatomy of the tongue, floor of mouth and oropharynx

A computed tomography (CT) technique is described which demonstrates the structures and tissue planes in the floor of mouth, tongue and oropharynx. The anatomy, which forms the basis for understanding pathological change, is given in detail and illustrated by axial and coronal images and line drawings.     

Hemiatrophy of the tongue and floor of the mouth demonstrated by computed tomography

Computed tomography can show hemiatrophy of the tongue and the floor of the mouth. The normal neuroanatomy of this region with regard to its motor supply is reviewed. In theory six variants of motor nerve lesions with hemiatrophy can be encountered, three of which are illustrated in this report. Knowledge of the muscular anatomy and the motor nerve supply to the tongue and floor of the mouth is helpful when evaluating lesions of the base of the skull with CT. This is particularly true for the lesions involving the trigeminal and hypoglossal nerves.     

Surgical treatment of advanced carcinoma of the floor of the mouth.

The anterior arch of the mandible is essential for satisfactory oral function and appearance. It can be preserved in surgical treatment of advanced cancers of the floor of the mouth by partial thickness resection. Surgery and radiation are approximately equally effective in the control of advanced (T3) primary lesions. A treatment plan is proposed which employs a combination of nondisabling surgical resection followed by immediate postoperative radiation. Of 19 patients with T2, T3, and T4 lesions treated and followed 1 year or more, 11 were free of cancer, including six who had positive lymph nodes. Of those dying of cancer, only one had local recurrence, while recurrence in the neck occurred in four. This report further strengthens the need for postsurgical radiation in certain situations.     

Results and indications of radiotherapy in the treatment of carcinoma of the mouth floor

175 carcinomas of the floor of the mouth were treated by radiotherapy in the years 1971-81: 47 T1 (26.9%) 87 T2 (49.7%) 19 T3 (10.8%) 22 T4 (12.6%). According to local extension the primary was treated by curietherapy in 92 patients (52.6%), external radiotherapy plus curietherapy boost in 8 (4.6%), radiosurgical combinations in 25 (14.3%) and external radiotherapy alone in 50 (28.5%). 131 patients were initially N0 (74.9%) 23 N1 (13.1%) 21 N2-3 (12.0%). The treatment on the nodal areas was: wait and see in 84 patients (48.0%) surgery in 39 (22.3%) radiosurgical combinations in 21 (12.0%) external radiotherapy alone in 31 (17.7%). Relapses free survival at 2 and 5 years was respectively 52.5% and 44.1%. Local control was obtained for 37/41 T1 cases (90.2%) 58/71 T2 (81.7%) 9/25 T3-T4 (36.0%). 37/137 patients with adequate follow-up (greater than or equal to 1 year) experienced some radionecrotic complications (27.0%). The overall incidence of the second tumors was 7.3% (10 cases).     

Sonography of the tongue and floor of mouth. Part I: Anatomy

Normal structures of the tongue and floor of the mouth were studied using anatomic sections cut with a stainless steel band saw. The sections were performed on the same planes as used in US and CT scanning. The ultrasound studies were carried out with 20 young and healthy volunteers. CT images were obtained from head-neck preparations that were subsequently used for anatomic sectioning. On comparing these sections to US and CT images, normal structures including intrinsic and extrinsic tongue muscles, vessels and salivary glands were identified. Knowledge of the anatomic landmarks is mandatory for optimal US image reading.     

Oropharynx, oral cavity, floor of the mouth: CT and MRI

Pretherapeutic staging of tumors of the oropharynx, the oral cavity and the floor of the mouth is important and should be thorough and exact to ensure appropriate therapy. Particularly important is the assessment of infiltration of deeper compartments and the topographic relationship of tumor to vascular structures (lingual artery and vein, hypoglossal nerve), or the presence of spread of the tumor across the midline. As spread of tumor may occur to a large degree underneath normal appearing mucosa, clinical assessment of the true tumor extent is difficult.In the last 20 years computed tomography (CT) has proved its value as a supplementary non-invasive method and established its role in modern diagnostic evaluation. Magnetic resonance imaging (MRI) is an non-invasive scanning method that offers excellent tissue contrast. Ultrasonography (US) is of secondary importance, but provides useful guidance due to its wide availability and its easy use.This paper aims to depict the possibilities of modern CT and MRI to provide 'one-stop-shopping' information to the clinician as a basis for the right therapeutic approach and correct estimation of the individual patient's prognosis. A clear problem oriented imaging strategy with standardized diagnostic criteria will lead to a cost effective evaluation.     

CT scanning in patients following surgery on the tongue and floor of mouth

Computed tomographic (CT) scanning was performed on 15 patients who had undergone carefully documented major surgery for malignancy to the tongue and floor of mouth in order to assess appearances of the face and neck following extensive resection. The appearances following a variety of operations, often with reconstruction, were identified. Familiarity with the normal post-operative anatomy allows the recognition of small volume recurrent tumour and the implementation of appropriate treatment.     

Masses of the tongue and floor of the mouth: findings on magnetic resonance imaging

The purpose of this study was to determine the value of MR imaging for the demonstration of masses in the tongue and floor of the mouth. Nine patients were prospectively examined with MR imaging after physical examination. Imaging protocol included T2 and contrast-enhanced and non-contrast-enhanced T1-weighted turbo spin-echo sequences, and the findings were compared with surgical and histopathological results. Histopathological examination revealed four squamous cell carcinomas, one adenoid cystic carcinoma, two tongue abscesses, and one chronic inflammatory change. The other case was diagnosed as hemangioma depending on clinical and imaging findings alone. In cases with squamous cell carcinoma, staging was done on the basis of MR imaging findings, and was found to be T4 in two cases, T3 in one case, and T2 in another. The primary role of MR imaging of the tongue and oropharynx is not to make a tissue diagnosis. Multiple deep biopsies are mandatory for the differentiation of other inflammatory and neoplastic lesions. Magnetic resonance imaging produces coronal and sagittal image planes to assess the volume and spread of the lesion and helps the surgeon determine the direction in which the biopsy should be performed. Received: 4 October 1999; Revised: 31 January 2000; Accepted: 6 April 2000