Cystic teratoma of the ovary: CT detection

Computed tomography (CT) was performed in 38 patients with 41 benign cystic teratomas of the ovary and two patients with malignant transformation. CT depicted all tumors. The presence of fat in 40 of 43 cases (93%), tooth or calcification in 24 of 43 (56%), Rokitansky protuberance in 35 of 43 (81%), tufts of hair in 28 of 43 (65%), and a fat-fluid level in five of 43 (12%) allowed a definite diagnosis of ovarian cystic teratoma in 42 of 43 cases (98%). In the two cases of malignancy, single large (greater than 10 cm) plugs (with uptake of contrast medium in one) with a cauliflower appearance and an irregular border forming an obtuse angle with the inner wall of the cyst suggested malignant transformation. In three cases of benign cystic teratoma, a mucinous tumor (one benign, one borderline, one malignant) arising in the same ovary was seen at pathologic examination but was only diagnosed with the help of CT in two of three cases. Thickening of the tube was noted in two cases of torsion of the adnexa. CT findings were compared with findings at radiography of the abdomen and hysterosalpingography in 30 cases, ultrasound in 31, and magnetic resonance imaging in three. This study demonstrated that CT was the best procedure for imaging cystic teratomas of the ovary.     

Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy

BACKGROUND: Complex fractures of the distal part of the humerus can be difficult to characterize on plain radiographs and two-dimensional computed tomography scans. We tested the hypothesis that three-dimensional reconstructions of computed tomography scans improve the reliability and accuracy of fracture characterization, classification, and treatment decisions. METHODS: Five independent observers evaluated thirty consecutive intra-articular fractures of the distal part of the humerus for the presence of five fracture characteristics: a fracture line in the coronal plane; articular comminution; metaphyseal comminution; the presence of separate, entirely articular fragments; and impaction of the articular surface. Fractures were also classified according to the AO/ASIF Comprehensive Classification of Fractures and the classification system of Mehne and Matta. Two rounds of evaluation were performed and then compared. Initially, a combination of plain radiographs and two-dimensional computed tomography scans (2D) were evaluated, and then, two weeks later, a combination of radiographs, two-dimensional computed tomography scans, and three-dimensional reconstructions of computed tomography scans (3D) were assessed. RESULTS: Three-dimensional computed tomography improved both the intraobserver and the interobserver reliability of the AO classification system and the Mehne and Matta classification system. Three-dimensional computed tomography reconstructions also improved the intraobserver agreement for all fracture characteristics, from moderate (average kappa [kappa2D] = 0.554) to substantial agreement (kappa3D = 0.793). The addition of three-dimensional images had limited influence on the interobserver reliability and diagnostic characteristics (sensitivity, specificity, and accuracy) for the recognition of specific fracture characteristics. Three-dimensional computed tomography images improved intraobserver agreement (kappa2D = 0.62 compared with kappa3D = 0.75) but not interobserver agreement (kappa2D = 0.24 compared with kappa3D = 0.28) for treatment decisions. CONCLUSIONS: Three-dimensional reconstructions improve the reliability, but not the accuracy, of fracture classification and characterization. The influence of three-dimensional computed tomography was much more notable for intraobserver comparisons than for interobserver comparisons, suggesting that different observers see different things in the scans-most likely a reflection of the training, knowledge, and experience of the observer with regard to these relatively uncommon and complex injuries.     

Complicated cholesteatomas: CT findings in inner ear complications of middle ear cholesteatomas

Patients with facial palsy and middle ear disease, which may be chronic but clinically occult, may have a cholesteatoma with extension medially along the facial canal. In two patients, axial computed tomographic (CT) scans demonstrated involvement of the medial petrous bone. Patients with vertigo and chronic middle ear disease may have a cholesteatoma with a "fistula" between the middle and inner ears. Although the fistula usually involves the lateral semicircular canal, the cholesteatoma may pass through the oval window. In two patients, coronal CT scans showed extension to the oval window in one and through it in the other.     

Two-dimensional and three-dimensional computed tomography for the classification and characterisation of tibial plateau fractures

Background

Complex tibial plateau fractures can be difficult to characterise on plain radiographs and two-dimensional computed tomography (2D CT). The present study evaluated whether three-dimensional computed tomography (3D CT) reconstructions can improve the reliability of complex tibial plateau fracture characterisation and classification.

Methods

Forty-five consecutive intra-articular fractures of the tibial plateau were evaluated by six independent observers for classification according to standard systems and for the presence of six characteristics: (1) posteromedial shear fracture; (2) coronal plane fracture; (3) lateral condylar impaction; (4) medial condylar impaction; (5) tibial spine involvement; and (6) separation of tibial tubercle necessitating fixation. Two rounds of characterisation and classification were performed: the first classification after a combination of plain radiographs and 2D CT and the second one after 3D CT information were added.

Results

3D CT improved the average ‘inter’-observer reliability of the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) classification (κ2D = 0.536, 95% confidence interval (CI): 0.481–0.591 vs. κ3D = 0.545, 95% CI: 0.478–0.612), the Hohl and Moore classification (κ2D = 0.668, 95% CI: 0.605–0.732 vs. κ3D = 0.746, 95% CI: 0.605–0.732) and of the Schatzker classification (κ2D = 0.545, 95% CI: 0.494–0.596 vs. κ3D = 0.596, 95% CI: 0.538–0.654). ‘Intra’-observer reliability also improved non-significantly for all systems after the addition of 3D CT for individual observers.3D CT did improve the ‘intra’-observer reliability for the identification of the following fracture characteristics: coronal plane fracture (average κ2D = 0.700, interquartile range (IQR): 0.551–0.820 vs. average κ3D = 0.774, IQR: 0.692–0.847); lateral condylar impaction (average, κ2D = IQR: 0.675–0.901 to 1.000 vs. average, κ3D = 0.785, IQR 0.737–0.807); medial condylar impaction (average κ2D = 0.631, IQR: 0.537–0.670 vs. κ3D = 0.719, IQR: 0.679–0.895); tibial spine involvement average (κ2D = 0.621, IQR 0.545–0.678 vs. average κ3D = 0.705, IQR: 0.652–0.794); separation of tibial tubercle necessitating fixation (average κ2D = 0.332, IQR: 0.080–0.574 vs. average κ3D = 0.441, IQR: 0.325–0.681). The only improvement that was found to be statistically significant was for recognition of medial condylar impaction as the IQR did not overlap.3D CT had limited influence on average ‘inter’-observer reliability for the recognition of all specific fracture characteristics (κ2D = 0.488 vs. κ3D = 0.485, both moderate agreement for all fracture characteristics) but showed a non-significant improvement of the recognition of coronal plane fractures (fair to moderate; κ2D = 0.398, 95% CI: 0.273–0.523 to κ3D = 0.418, 95% CI: 0.262–0.574) and recognition of impaction of the lateral condyle (κ2D = 0.614, 95% CI: 0.467–0.760 to κ3D = 0.693, 95% CI: 0.538–0.849).

Conclusions

The added value of 3D CT after 2D CT is limited and does not significantly improve reliability of characterisation and classification of tibial plateau fractures.     

Temporal sequence of mammary intraductal proliferations, ductal carcinomas in situ and adenocarcinomas induced by 1-methyl-1- nitrosourea in rats

An experimental model for mammary carcinogenesis has been described in which intraductal proliferations, ductal carcinomas in situ and adenocarcinomas can be readily detected and the frequency of their occurrence quantified. The objective of the experiment reported in this study was to determine the latency period between carcinogen administration and the occurrence of each of these types of lesion. A total of 150 female Sprague-Dawley rats were injected i.p. with 50 mg 1- methyl-1-nitrosourea (MNU)/kg body wt at 21 days of age. Groups of 30 rats each were killed at 7, 14, 21, 28 and 35 days post-carcinogen. Mammary intraductal proliferations were the first detected lesions and were observed in 20% of the animals at 14 days following carcinogen administration. At 21 days post-carcinogen ductal carcinomas in situ and adenocarcinomas were observed. The number of each type of lesion increased with time post-carcinogen, but the temporal pattern of occurrence was different among lesion types. The pattern of lesion occurrence was consistent with intraductal proliferations being a precursor lesion for ductal carcinomas in situ and adenocarcinomas. Furthermore, the data imply that ductal carcinomas in situ represent one pathway of morphological progression by which intraductal proliferations evolve into invasive carcinomas, but that this lesion type, as currently defined histologically, may not be an obligatory intermediate in morphologic progression. These findings are consistent with emerging evidence of multiple but distinct pathogenetic pathways leading to mammary carcinomas that display different morphological patterns and biological activities.      

Wilms' tumor and gonadal dysgenesis in a child with the 2q37.1 deletion syndrome

Here we report Wilms' tumor, gonadal dysgenesis and a bifid uterus in an 18-month-old female with a terminal deletion of the long arm of chromosome 2 [46, XX, del(2)(q37.1)]. Since Wilms' tumor has been previously reported in the 2q37 deletion syndrome, the present observation raises the question of whether a tumor susceptibility gene maps to chromosome 2q37 and suggests giving consideration to the possible occurrence of Wilms' tumor in the course of disease.