Pineal parenchymal tumour with intermediate differentiation
Pineal parenchymal tumours with intermediate differentiation (PPTID) are, as the name suggests, tumours which fall between pineocytoma (well differentiated, WHO grade I) and pineoblastomas (poorly differentiated, WHO grade IV) and are considered WHO grade II / III tumours 2. This is a tumour encountered at all ages, but particularly of middle age adults (20-70 years of age) with slight female predilection, similar to that of pineocytomas 4.
Their radiographic appearance and biological behaviour are also intermediate. They may invade adjacent structures and also spread along CSF (imaging of the intire craniospinal axis is required 3).
Pineal parenchymal tumour with intermediate differentiation have similar macroscopic appearance to pineocytomas, appearing relatively well circumscribed with heterogeneous cut surface 4.
Two microscopic patterns are encountered, sometimes co-existing 4:
The lobulated pattern, poorly defined lobules are separated from each other by large fibrous vessels 4.
- 1. Prayson Richard A. and Mark L. Cohen. Practical differential diagnosis in surgical neuropathology. Humana Press, 2000. ISBN: 0896038173, 9780896038172.
- 2. Dumrongpisutikul N, Intrapiromkul J, Yousem DM. Distinguishing between germinomas and pineal cell tumors on MR imaging. AJNR Am J Neuroradiol. 2011;33 (3): 550-5. AJNR Am J Neuroradiol (abstract) - doi:10.3174/ajnr.A2806 - Pubmed citation
- 3. Smith AB, Rushing EJ, Smirniotopoulos JG. From the archives of the AFIP: lesions of the pineal region: radiologic-pathologic correlation. Radiographics. 2010;30 (7): 2001-20. Radiographics (full text) - doi:10.1148/rg.307105131 - Pubmed citation
- 4. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK "WHO Classification of Tumours of the Central Nervous System. 4th Edition Revised" ISBN: 9789283244929
Pineal region masses
The pineal region is anatomically complex and plays host to a number of unique masses and tumours as well as potentially affected by many entities seen more frequently elsewhere in the brain.
- cystic non-neoplastic lesions
- pineal parenchymal tumours
- germ cell tumours
- tumours also encountered in the pineal region
- pineal gland metastases
- vascular lesions