Conservative management of vestibular schwannomas of 15 to 31 mm intracranial diameter.

OBJECTIVE: To study the natural course of vestibular schwannomas 15 to 31 mm in diameter. METHODS: A retrospective study of 45 patients conservatively managed with interval scanning was performed. Outcome measures were: changes in tumour size, clinical features and hearing. A tumour was considered to be growing if it increased in size by more than 2 mm. RESULTS: Initial tumour sizes ranged from 15 to 31 mm, with a mean (± standard deviation) diameter of 20.1 ± 4.3 mm. The duration of follow up ranged from 6 months to 14 years (median, 3 years). Tumours grew in 11 cases (24.4 per cent), remained stable in 30 cases (66.7 per cent) and regressed in 4 cases (8.9 per cent). The overall mean tumour growth rate was 0.9 ± 2.2 mm per year; in growing tumours, it was 3.6 ± 2.9 mm per year. CONCLUSION: Outcomes were similar to those reported for smaller tumours. These findings suggest that patients with medium or moderately large tumours can be safely offered an initial period of conservative management before intervention is considered.

Radionuclide bone imaging for detection of mandibular invasion by squamous cell carcinoma.

The assessment of mandibular invasion is an important part of the pre-operative staging of oropharyngeal squamous cell carcinoma. When bone is surgically resected, histology often shows no direct bone invasion, yet such resections are associated with post-operative complication and morbidity. This prospective study of a large group of patients aims to lay down criteria for bone invasion using radionuclide bone imaging and orthopantomography, and to test their effectiveness when compared with histological analysis. 77 patients with proven squamous cell carcinoma of the oral cavity were investigated pre-operatively by radionuclide bone imaging and orthopantomography. All had bone resected as part of complete resection of the tumour. One patient had systemic bone metastases and was, therefore, excluded. In the remaining 76 patients, there were four false positive assessments for bone invasion radiologically and no false negatives. There were 48 true positive results and 24 true negatives, giving a sensitivity of 100% and specificity of 86%. It is concluded that correct application of the outlined criteria for bone invasion demonstrated that radionuclide bone imaging and orthopantomography are a sensitive test for bone invasion, with an acceptable level of specificity.

Magnetic resonance imaging in the assessment of cervical nodal metastasis in oral squamous cell carcinoma.

OBJECTIVE: The accurate pre-operative assessment of cervical lymph nodes is a well recognized problem in the management of patients with oral squamous cell carcinoma. Imaging techniques have improved the accuracy of staging but cannot determine if nodal enlargement is due to reactive changes or malignant involvement. We assessed the diagnostic performance of magnetic resonance imaging (MRI) in detecting metastatic disease within the neck in oral cancer patients. MATERIALS AND METHODS: A retrospective study was performed on 58 patients treated for oral squamous cell carcinoma. All patients had pre-operative MR imaging including axial and coronal short tau inversion recovery (STIR) sequences and pre- and post-gadolinium axial T1 weighted sequences. Nineteen patients had bilateral neck dissections giving 77 sides of neck for study. MR images were reviewed for nodal involvement at each anatomical level within the neck and correlated with findings at histology. RESULTS: Twenty-seven of the 77 sides of neck contained histologically positive nodes (35.1%). MRI sensitivity was 66.7% and specificity 68%. There was a false-negative rate of 20.9% and false-positive rate of 47.1%. Some enlarged, histologically positive nodes were not detected by MRI. Furthermore, in five cases the only histological evidence of nodal malignancy was the presence of a micrometastasis (<3 mm tumour deposit). MRI detected two of these. CONCLUSION: MRI lacks sufficient sensitivity and specificity to replace elective neck dissection for both staging and prognostic purposes.

Abdominal wall haematoma in anti-coagulated patients: the role of imaging in diagnosis.

Abdominal wall haematomas are uncommon, difficult to diagnose clinically and often associated with systemic anti-coagulation. Seven cases together with the imaging results are presented and the characteristic features and potential pitfalls are discussed. Ultrasound is the first line investigation but the results can be misleading and computed tomography (CT) is often required to confirm the diagnosis.

Correlation of histopathologic findings with clinical and radiologic assessments of cervical lymph-node metastases in oral cancer.

The accuracy of preoperative diagnosis of cervical lymph-node metastasis in oral cancer was assessed by comparing the histopathologic findings in 136 sides of neck dissection with physical examination under anaesthesia (EUA) and computerized tomography (CT) assessments of the metastatic status. The overall accuracy of EUA and CT assessments was 72% and 73%, respectively, and a combination of both methods resulted in sensitivity and specificity rates of 55% and 78%, respectively. Twenty-three of the 51 histologically positive necks had been assessed as negative on both EUA and CT. Six of these contained only micro-metastases, and in another 10, the largest positive node was 1.5 cm or less. Extracapsular spread of metastatic carcinoma was found in 12 of the 23 EUA and CT false-negative dissections. Most of the 21 histologically positive necks which had been correctly assessed as positive on both EUA and CT contained enlarged metastatic nodes, fused nodal masses, extensive extracapsular spread, or more than one of these features. Three of the 85 histologically negative necks had been assessed as positive on both EUA and CT; eight had been positive on EUA alone, and another eight on CT alone. Reactive nodal hyperplasia or sialadenitis was seen in most false-positive dissections. We conclude that the accuracy of preoperative diagnosis of metastasis by routine methods remains poor, and that EUA and CT are reliable only in patients with bulky metastatic deposits.

The role of magnetic resonance imaging in the assessment of local recurrent breast carcinoma.

Experience with magnetic resonance imaging (MRI) of the breast remains limited. MRI studies to date have shown that differentiation of carcinoma from certain benign breast changes can be difficult. The problem of suspected tumour recurrence in patients with known but treated breast carcinoma is considered. Forty-five patients were studied, all having been treated by lumpectomy combined with radiotherapy and/or chemotherapy. Suspicion of recurrence was suggested by X-ray mammography or clinically by the presence of a current breast mass, breast pain, or nipple discharge. The principle differential diagnosis rested between post-treatment fibrosis and recurrent tumour. Axial and sagittal images were obtained using T1-and T2-weighted pulse sequence. Images were enhanced with intravenous gadolinium DTPA in cases where there was a mass. The tomographic format and inherent high soft tissue contrast provided by MRI are of particular value in this situation. The morphological appearances of recurrent tumour, fibrosis, and other post-radiation affects are described and compared. MRI allowed accurate differentiation in the majority of case. In equivocal cases enhancement of mass lesions with gadolinium DTPA provided excellent confirmatory evidence of recurrent tumour.

Can ultrasound replace the intravenous urogram in preliminary investigation of renal tract disease? A prospective study.

The intravenous urogram has long been the mainstay of urinary tract imaging in adult practice. It has been shown recently that in many clinical situations the routine use of intravenous urography is no longer justified and in some situations avoidance of adverse contrast reactions, reduced examination time and significant cost reduction. In order to assess the clinical and financial aspects of a change in practice in our department, a prospective study was undertaken over a total of 10 weeks when 328 patients who were referred for intravenous urography were also examined independently by ultrasound combined with the plain abdominal radiograph. The results were compared and in 81.4% of cases the two techniques yielded identical information. Ultrasound plus a plain abdominal radiograph provided more diagnostic information in a further 12.5% of cases, whilst intravenous urography was more informative in only 6.1%. The findings of the study are discussed by considering the main clinical groups and comparing the relative yields of ultrasound and urography. A scheme of routine urinary tract investigations using ultrasound and the plain abdominal radiograph is proposed. We estimate a 58% reduction in number of urographic examinations while retaining diagnostic accuracy. The financial and planning implications for our department are discussed.

A large soft-tissue chondroma arising from the posterior mediastinum.

A case of a large intrathoracic soft-tissue chondroma arising from the posterior mediastinum is described. The plain radiographic and computed tomography (CT) findings are correlated with the histopathology.