Pseudotumoural hemicerebellitis: imaging findings in two cases

Abstract

Pseudotumoural hemicerebellitis is exceedingly rare. It may closely resemble a tumour either clinically or on imaging, and a high index of suspicion is required to avoid unnecessary surgical procedures. MRI is the most useful diagnostic tool, and reveals a swollen cerebellar hemisphere, hyperintense in T(2) weighted images. A pattern of predominantly pial contrast enhancement, absence of a well-defined mass and regression of the abnormalities in follow up examinations help to rule out malignancy. We report two cases of pseudotumoural cerebellitis (an 11-year-old girl and a 9-year-old boy) studied with CT and MRI.

Advanced neuroimaging findings of pseudotumoral hemicerebellitis in an elderly male requiring surgical decompression

“…Interval improvement of imaging findings and the absence of a well-defined mass are characteristic. 2 The majority of cases show facilitated diffusion, as was seen in our patient. 13 However, Jaggi et al 8 reported a case of bacterial cerebellitis in which restricted diffusion was present.…”

Pseudotumoral hemicerebellitis with hemorrhage

“…[2] It has an unpredictable clinical course, and while some patients have no symptoms, others may have fulminant course leading to death. Rarely, surgical intervention may be necessary if complications such as tonsillar herniation, brainstem compression, and acute hydrocephalus develop.…”

“…Examination of the CSF is not obligatory for diagnosis and may be normal, as was seen in the present case. [12] MRI is the imaging modality of choice in acute cerebellitis and typically reveals a bilaterally symmetric disease or may be normal. [3] Unilateral presentation of acute cerebellitis (hemicerebellitis) is rare, while pseudotumoral hemicerebellitis is exceptionally rare.…”

Acute Pseudotumoral Hemicerebellitis in a Child

“…[1][2][3][4][5][6][7][8][9] In all these 9 cases, as in our patient, the clinical symptomatology was characterized by progressive signs of intracranial hypertension, such as headache, vomiting, and neck stiffness, and none of them had cerebellar signs, namely, ataxia or dysarthria.…”

“…After at least 4 weeks from the onset, only a residual mild hyperintensity in T2-weighted images of the affected cerebellar hemisphere has been reported. 1,[3][4][5] In our patient, disappearance of pial foliaform contrast and reduction of cerebellar swelling was already evident after 2 weeks, whereas a persistent increase in the signal of the cerebellar cortex in T2-weighted and fluid-attenuated inversion recovery images has been detected as sequelae in the following 18 months. Supposedly, these findings are compatible with focal atrophy and secondary gliosis.…”