Interhemispheric lipoma with variable callosal dysgenesis: relationship between embryology, morphology, and symptomatology

Eight interhemispheric lipomas (five tubulonodular lipomas and three curvilinear lipomas) were examined by magnetic resonance imaging (MRI). The purpose was to further investigate the relationship between the morphology of the different subtypes and the clinical presentation. The imaging findings were reviewed in light of a recent theory on the development of the corpus callosum. Interhemispheric lipomas should be considered as one entity with a variable expression depending on the severity and/or the time of the insult. Curvilinear lipomas can be either small or extensive and are usually not symptomatic. Tubulonodular lipomas can be either predominantly anterior or posterior in location. The anterior subtype appears to be a more severe form of tubulonodular lipoma. The associated structural abnormalities are most likely responsible for the symptoms, rather than the lipoma itself. Magnetic resonance imaging allows a more precise timing of the insult, resulting in the development of a lipoma. The knowledge of the embryology between the 6th and the 20 h week is important to explain these abnormalities. Until now it has been accepted that the corpus callosum develops in an orderly fashion. A recent theory has demonstrated that this is not necessarily true, and that fibers can cross the midline at any place irrespective of the normal development. This theory explains the sometimes amorphous appearance of the remnant of the corpus callosum if a lipoma is present.Correspondence to: Ph. Demaerel     

Magnetic resonance imaging in lesions of the eye globe

Magnetic Resonance Imaging (MRI) findings in 22 patients with lesions of the globe were examined. There were 16 cases of malignant uveal melanoma, 2 cases of retinoblastoma, 3 cases of hemorrhagic choroidal detachment and 1 case of senile macula degeneration. MRI adequately depicted the lesions in 20 cases. In two cases MRI findings were unconclusive due to movement artifacts of the eye globe. Fourteen out of 16 uveal melanomas displayed typical T1 and T2 shortening. In the two other cases the hypointense aspect on T2-weighted images was less pronounced due to a lesser amount of melanin in the lesions as demonstrated by subsequent histology. Unlike with CT, the tumoral lesions could clearly be differentiated from subretinal exudate. The case of senile macula degeneration, two retinoblastomas and two cases of hemorrhagic choroidal detachment had the same MRI characteristics as melanomas.     

Intraarterial low-dose streptokinase infusion in the treatment of acute renal thromboembolism

A case of acute renal thromboembolism treated by intraarterial low dose streptokinase infusion is reported. The treatment appears effective, safe and less-invasive then surgery, with quick relief of pain and normalisation of blood pressure and renal function. It is concluded that intraarterial infusion of thrombolytic agents should be attempted first in the treatment of renal arterial thrombo-embolism.     

Left spermatic vein in left-sided vena cava

The left spermatic vein was found to drain directly into a left-sided vena cava in a patient with left varicocele. The implications for embolization of this anomaly are obvious.     

DIFFICULTIES AND DILEMMAS IN THE MANAGEMENT OF CONGENITAL ANOMALIES IN TWIN PREGNANCY

Both the incidence of twin pregnancy and the demand for prenatal diagnosis are increasing. Unfortunately, biochemical screening and ultrasound scanning are less reliable for prenatal diagnosis in twin pregnancies than in singletons. Amniocentesis and chorionic villous biopsy are usually diagnostic in singleton pregnancies but may be marred by sampling errors in twin gestations. Where a congenital anomaly has been diagnosed in a twin pregnancy, difficult decisions may have to be made, especially if one twin is unaffected. In these cases, special skills are required to ensure that adequate information, psychological support and optimal medical care are provided.     

Cerebral venous angiomas

Summary Sixteen cases of cerebral venous angiomas, seven cerebellar and nine supratentorial were imaged by magnetic resonance, using a T1 sequence and a motion compensated T2 sequence. The transcerebral draining vein of the lesion could be identified in thirteen out of sixteen patients. On T1-weighted images all the lesions were hypointense. On T2-weighted images, five lesions were hypointense, and eleven were hyperintense consistent with slow flow. In three cases the lesion was hemorrhagic. Three lesions with hypointense aspect on T1 and hyperintense aspect on T2-weighted images were only seen in retrospect, due to partial volume averaging in two and concomitant chronic hemorrhage in one. Before contrast, the peripheral dilated medullary veins could only be identified in five cases. On T2-weighted images, in three of these lesions the signal was higher than in the draining veins, pointing to a slower flow. After intravenous administration of Gadolinium, performed in twelve patients, the main transcerebral draining vein as well as the peripheral medullary veins could be well identified in all patients.     

Anaplastic (malignant) ganglioglioma arising from heterotopic grey matter nodules

Summary Anaplastic ganglioglioma is a rare malignant neoplasm. The short clinical course and the anaplastic histological features are characteristics of malignant ganglioglioma. Immunohistochemistry is necessary for the final diagnosis. The MRI appearances are described here for the first time in literature. Nodular grey matter heterotopias had been demonstrated and the patient developed an anaplastic ganglioglioma two years later, on the same place where the grey matter heteropias had been seen. This finding supports the hypothesis that these tumours may arise from grey matter nodules.