Intracranial teratoma

Surgical resection pathology report

Much of the specimen consists of altered blood clot but there are fragments of gliotic cerebellar tissue within which there is a large cystic lesion. This lesion is lined by epithelium and the epithelium varies between simple cuboidal ciliated epithelium to stratified squamous epithelium, although the epithelium is not keratinising. Goblet cells are occasionally noted. Hair shafts and glandular structures are also identified, as is bone and adipose tissue. The cyst has clearly ruptured and there is a foreign body giant cell reaction including cholesterol clefts.                            

CommentThe appearances are of a mature teratoma which has ruptured resulting in haemorrhage. There are no malignant elements identified in the tissues examined.

Posterior fossa lesion - Ruptured mature teratoma.

Unusual posterior fossa abnormality. Initially it was thought to be a haemorrhage secondary to a vascular abnormality given the high attenuation and areas of calcification. However, the patient had a 2 month history. There is minimal perilesional oedema, which would be unusual for haemorrhage. There is also pronounced obstructive hydrocephalus with marked dilatation of the third ventricular recesses. This degree of hydrocephalus is unlikely to have occurred acutely, particularly because the patient was relatively well. 

The MR signal characteristics are not in keeping with a spontaneous haemorrhage. Rather most of the lesion appears cystic with presumably proteinaceous material. There is ana solid enhancing component and areas of calcification, potentially fat and blood products. 

The midline location, apparent slow growth and mixed solid cystic lesion with calcified components suggestssuggest a teratoma.