Pineocytoma - causing hydrocephalus

Case contributed by Frank Gaillard
Diagnosis certain


Patient presented with headaches and obstructive hydrocephalus.

Patient Data

Age: Adult
Gender: Male

CT brain


Single image following biopsy and third ventriculostomy demonstrates a pineal region soft tissue mass. A small amount of blood is seen in the occipital horn on the right. Ventricles remain dilated. 

MRI brain


A well circumscribed mass is located in the region of the pineal gland. It is a little heterogeneous with multiple small regions of cyst formation (on T2) most marked anteriorly, probably at the site of biopsy. It enhances vividly and compresses the tectum and obstructs the upper part of the aqueduct with resultant hydrocephalus, treated with a third ventriculostomy, widely patent. 

The patient had had a biopsy at the time of the third ventriculostomy. 


Sections show several small fragments comprised of tumor cells with uniform round nuclei and occasional rosette formations. There are no mitotic figures, necrotic areas, or significant nuclear pleomorphism seen. Immunohistochemistry reveals that the tumor cells are strongly positive for synaptophysin and neuron-specific enolase, including the rosette formations. Processes, particularly within the rosettes, are identified with the phosphorylated and non-phosphorylated neurofilaments. Reticulin stain confirms the absence of lobular architecture of a normal pineal gland. The tumor cells are negative for chromogranin and LCA. The MIB-1 index is very low.

FINAL DIAGNOSIS: pineocytoma

Case Discussion

This case demonstrates typical appearances of a pineocytoma, confirmed histologically. The patient remains well. 

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