Teratoma - suprasellar

Case contributed by A.Prof Frank Gaillard

Presentation

Discordant gaze palsy. Patient drowsy.

Patient Data

Age: 25 years
Gender: Female
CT

CT brain

A large suprasellar lesion is present. The lesion comprises a homogeneously enhancing solid component with intrasellar extension and a larger posterosuperior cystic component which is of slightly greater density (~11HU) than CSF. Additonally to the right of the base of the lesion is a component with fat density and calcification. 

There is compression of the midbrain and pons as well as dilatation of the lateral ventricles consistent with obstructive hydrocephalus. No tonsillar herniation. No haemorrhage or bony destruction identified. The remainder of the brain is unremarkable.

A ventricular shunt was placed into the ventricles to relieve hydrocephalus, and the patient went onto have an MRI, although due to agitation image quality was suboptimal. 

MRI

MRI brain

MRI scan was obtained with difficulty due to patient motion. Suprasellar mass which displaces the pituitary stalk to the right is noted, which is mostly cystic (4.1cm) with a large avidly enhancing nodule (15mm) and a fatty component on the right, inferiorly. The optic chiasm lies just anterior to this lesion. The lesion displaces the left optic tract inferolaterally. There is prominence of the optic nerve sheath bilaterally without overt papilloedema. The third ventricle has been obliterated and the cerebral peduncles are splayed by this lesion.

Tiny amount of blood layers in the right occipital horn, likely related to the drain insertion. No abnormal diffusion restriction detected.

Although the patients concious state improved following ventricular shunting, vision deteriorated and a second drain was placed into the cystic component of the tumour. 

The patient's vision improved, and she was followed up a few weeks later with a repeat MRI. 

MRI

MRI brain

There is significant increase in the size of the solid component of the suprasellar tumour in comparison with last MRI. It shows irregular margin and measures now about 31 x 28.5 x 26.7 mm. It remains suprasellar in location with no intrasellar extension. It is hypointense on T1 and  hyperintense on T2/FLAIR  It shows homogeneous intense enhancement. There is no evidence of diffusion restriction.  There is significant reduction in the size of the cystic component, seen superior and right lateral aspects to the mass lesion compared to the last MRI, in keeping with shunt drainage. 

Previously noted small component of high T1/T2 signal intensity extends just posterior to the right posterior clinoid process. 

The mass displaces the pituitary stalk to the right side and optic chiasm lies just anterior to it, with splayed optic tracts and swollen hyperintense right optic nerve adjoining the chiasm.

Ventricle remain decompressed by the shunt catheters.  The tip of right parietal shunt is within the frontal horn of right lateral ventricle. The tip of right frontal shunt is seen within the left temporal horn of left lateral ventricle, after crossing the tumour's posterolateral margin.

Pathology

Histology

The patient went on to have a craniotomy and excision of the both the solid component and the fatty / calcified eccentric component. 

MICROSCOPIC DESCRIPTION: Paraffin sections from specimens 1 to 3 show solid sheets of non-keratinizing squamous epithelium along with many fibrovascular stromal cores.  The surrounding stroma is chronically inflamed.  There is no cellular atypia. No calcification is identified. In specimen 4 some additional features are seen, which include sheets of mature fat intimately associated with mature bone and some fibrous tissue.  A small island of mature bone is seen embedded within fat. These additional features, if confirmed to be intrinsic part of the tumour, are not seen in a craniopharyngioma.

FINAL DIAGNOSIS: Mature teratoma.

Case Discussion

This case illustrates how similar a teratoma and a papillary craniopharyngioma can appear. In this case, the presence of mature adipose tissue enabled the preoperative diagnosis to be made. Although no malignant histological features were identified, the patient is being carefully followed up, and currently remains well. 

Histology courtesy of Dr Vivek Rathi

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Case information

rID: 17955
Case created: 28th May 2012
Last edited: 6th Nov 2015
Inclusion in quiz mode: Included

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