Membrane Structures Between Craniopharyngioma and the Third Ventricle Floor Based on the QST Classification and Its Significance: A Pathological Study

Abstract

The aim of this study was to clarify the relationship between craniopharyngiomas (CP) and the third ventricle floor by analyzing the membranes between them. Eight fetal specimens were first examined by hematoxylin and eosin and immunofluorescence staining to determine optimal markers for identifying membrane structures in the sellar region. Then, 17 CP with third ventricle floor involvement that had been removed by total en bloc resection through a transsphenoidal approach were examined. We found that the dura mater, arachnoid membrane, and pia mater could be seen to separate type Q tumors from the third ventricle floor. The arachnoid membrane and pia mater could be seen between type S tumors and the third ventricle floor. Pia mater could be seen between type T tumors and the third ventricle floor; however, at the origin point of the tumor, pia mater could be loosened or replaced by the tumor. Although some type T tumors compressed the third ventricle, the ependymal layer remained intact. Based on these embryonic and pathological data, we suggest that CP are nonneuroepithelial, epi-pia mater, and epi-third ventricle tumors.

Craniopharyngioma and the Third Ventricle: This Inescapable Topographical Relationship

“…More recently, we were able to compile and analyze comprehensively the cohort of CPs with a verified strictly 3V topography (n=245), as well as the historical cohort of well-described papillary CPs published in the medical literature (n= 350) ( 30 , 31 ). Although the strictly 3V topography has remained controversial throughout history, some authors considering it an exceptional, ectopic location ( 32 ), while others even argue over its validity ( 33 ), the surgical series by Depoujarny ( 18 ), Cao ( 20 ), and Zhou ( 21 ) contribute to verify this particularly challenging location, confirming the anatomical integrity of the 3VF found in numerous strictly 3V CPs in prior studies (see Table 1 ) ( 34 – 49 ). The optimal surgical view of the brain undersurface obtained through the EEA unequivocally show the ballooned and stretched infundibulum wrapping around the lower pole of these lesions, which stay hidden within the 3V chamber ( 13 , 14 , 40 , 46 ).…”

Extended Neuroendoscopic Endonasal Approach for Resection of Craniopharyngioma in Children

“…During the operation, the tumor must be separated from the pituitary stalk along the direction of the pituitary stem. If the pituitary stalk is in the center of the tumor, it must be incised to free the tumor and then try to protect the remaining pituitary stalk ( 36 , 38 , 39 ). For T-type craniopharyngiomas originating from the pars tuberalis, there is only a layer of pial mater between the tumor and the hypothalamus, which may adhere to the nerve tissue in the later stage and is not easy to be separated by surgery, and thus requires to find the boundary between the tumor and the normal tissue ( 35 , 39 ).…”

“…According to the QST classification of craniopharyngioma (35)(36)(37), the Q-type craniopharyngiomas originate from below the diaphragma sellae, and it is easy to separate the tumor during surgery even if it grows large and invades the hypothalamus, because of the barrier formed by the diaphragm sellae, arachnoid and pial mater between the tumor and the hypothalamus. Some cases with sellar septal tumors should be removed together with the diaphragm to avoid tumor recurrence (35,38).…”

Reinvestigating Tumor–Ventricle Relationship of Craniopharyngiomas With Predominantly Ventricular Involvement: An Endoscopic Endonasal Series Based on Histopathological Assessment

“…H&E, immunochemical, and immunofluorescence staining were performed as described previously ( 22 , 23 ). The antibodies used were Neurofilament (NF) (1:400, Abcam, ab7794), Glial Fibrillary Acidic Protein (GFAP) (1:200, Abcam, ab7260); pan Cytokeratin (Pan-CK) (1:300, Abcam, ab215838), Laminin β1 (1:400, Sigma, MAB1921P), CK5/6 (1:400, Sigma, SAB5600242), and Oxytocin (OXT) (1:400, Abcam, ab212193).…”

“…As described in our previous studies, the different portions of tumor capsule in contact with the third ventricle were marked during surgery, and each marked specimen was histologically examined separately to provide a comprehensive synthesis of overall information regarding the relationships between the tumor and third ventricle. H&E, immunochemical, and immunofluorescence staining were performed as described previously (22,23). The antibodies used were Neurofilament (NF) (1:400, Abcam, ab7794), Glial Fibrillary Acidic Protein (GFAP) (1:200, Abcam, ab7260); pan Cytokeratin (Pan-CK) (1:300, Abcam, ab215838), Laminin b1 (1:400, Sigma, MAB1921P), CK5/6 (1:400, Sigma, SAB5600242), and Oxytocin (OXT) (1:400, Abcam, ab212193).…”