Craniopharyngioma
Craniopharyngioma
- Craniopharyngiomas are rare, benign, lobulated/cystic tumors of the suprasellar and 3rd ventricle regions (rarely the pineal region) that derive from remnants Rathke's pouch.
- Rathke's pouch is an ectodermal placode along the roof of the cranial opening of the pharyngeal apparatus that stretches towards the floor of the 3rd ventricle (the infundibulum), and ultimately disconnects from the the pharyngeal apparatus, regresses, and forms the anterior pituitary gland.
- For reference: the infundibulum descends and develops into the posterior pituitary gland.
- The cystic fluid is dark and viscous and described as "machine oil"/"crankcase oil".
- If the cystic fluid spills out of the tumor, it can cause xanthogranulomatous inflammation.
Craniopharyngiomas often cause:
- Visual disturbance
- Secondary to involvement of the optic chiasm and peri-chiasmal optic pathway.
- Endocrinopathy
- Secondary to involvement of the pituitary gland, most notably.
- Especially diabetes insipidus
- Behavioral problems
- Secondary to involvement of the diencephalon, presumably.
- Cranipharyngiomas are most common in children BUT can present in adults, especially in middle-adulthood.
- Histopathology:
- Adamantinomatous variant: xanthogranulomatous inflammation, keratin, microscopic calcifications
- Papillary variant: pseudopapillae
- Treatment:
- Typically amenable to surgical resection (they are benign, lobulated, generally accessible tumors).
Rathke's cleft cyst
- Rathke's cleft cysts are congenital cysts that arise from the sellar/suprasellar region but are non-neoplastic (unlike craniopharyngioma).
- They are sellar remnants of Rathke's pouch; they represent a failure of this pouch lumen to fully degenerate.
- Rathke's cleft cysts are typically asymptomatic and are found, at autopsy, in ~ 20% of people.
- Differential radiographic diagnosis includes: craniopharyngioma or pituitary adenoma with cystic features.
References
- Adesina, Adekunle M., Tarik Tihan, Christine E. Fuller, and Tina Young Poussaint. Atlas of Pediatric Brain Tumors. Springer, 2016.
- Byun, Woo Mok, Oh Lyong Kim, and Dong sug Kim. “MR Imaging Findings of Rathke’s Cleft Cysts: Significance of Intracystic Nodules.” American Journal of Neuroradiology 21, no. 3 (March 1, 2000): 485–88.
- Gray, Frangoise, Charles Duyckaerts, and Umberto De Girolami. Escourolle and Poirier’s Manual of Basic Neuropathology. OUP USA, 2013.
- Tonn, Jörg-Christian, Manfred Westphal, and J. T. Rutka. Oncology of CNS Tumors. Springer Science & Business Media, 2010.
- Yachnis, Anthony T., and Marie L. Rivera-Zengotita. Neuropathology E-Book: A Volume in the High Yield Pathology Series. Elsevier Health Sciences, 2012.