Wang Kyu-Chang, Hong Seok Ho, Kim Seung-Ki, Cho Byung-Kyu
Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, South Korea.
Childs Nerv Syst. 2005 Aug;21(8-9):628-34. doi: 10.1007/s00381-005-1203-8. Epub 2005 Jul 30.
The surgical management of craniopharyngiomas has been among the most challenging neurosurgical procedures because of their complex topographical relationship with surrounding structures and high recurrence rate after subtotal resection. Craniopharyngiomas have been classified only by their location to determine an appropriate surgical approach without due regard to other factors that could affect the surgical results, such as the extent of adhesion to surrounding structures or the nature of the tumor.
We describe the role of the diaphragm sellae on the growth patterns of craniopharyngiomas from surgical experiences and pathological evidences, suggesting the classification of craniopharyngiomas into three categories by the level of origin and the competence of the diaphragm sellae: a tumor of subdiaphragmatic origin with competent diaphragm sellae, subdiaphragmatic with incompetent diaphragm sellae, and supradiaphragmatic.
Tumors in each category have shown peculiar topographical relationship with the optic chiasm, third ventricle, and also adhesion extents. The nature of the tumor itself, e.g., the composition of cystic and solid parts, may bring additional minor variations to the topographical features of a craniopharyngioma, but will maintain the major characteristics determined by its level of origin and competence of the diaphragm sellae.
This classification scheme, which considers the origin level, is clinically relevant and useful because optimal surgical approaches could be designed by considering multiple factors affecting surgical procedure and outcome, including the expected extent of adhesion and preferred sites of recurrence, as well as the topographical location of the tumor. In subdiaphragmatic tumors, which correspond to intrasellar and prechiasmatic tumors, a transsphenoidal approach could be reasonably attempted even with considerable suprasellar extensions because they tend to adhere to the intrasellar structures, and the superior surface of the tumor may be easily separated from the brain structures by pulling. Supradiaphragmatic tumors, however, may need a wider surgical approach that can provide direct vision of the tumor because of possible extensive adhesion.
颅咽管瘤的外科治疗一直是最具挑战性的神经外科手术之一，因为其与周围结构的复杂解剖关系以及次全切除术后的高复发率。颅咽管瘤仅根据其位置进行分类以确定合适的手术入路，而未充分考虑其他可能影响手术结果的因素，如与周围结构的粘连程度或肿瘤的性质。
我们根据手术经验和病理证据描述了鞍膈在颅咽管瘤生长模式中的作用，建议根据起源水平和鞍膈的功能将颅咽管瘤分为三类：起源于鞍膈下方且鞍膈功能正常的肿瘤、起源于鞍膈下方且鞍膈功能不全的肿瘤以及起源于鞍膈上方的肿瘤。
每类肿瘤与视交叉、第三脑室均呈现出独特的解剖关系以及粘连程度。肿瘤本身的性质，例如囊性和实性部分的组成，可能会给颅咽管瘤的解剖特征带来一些细微变化，但仍会保持由其起源水平和鞍膈功能所决定的主要特征。
这种考虑起源水平的分类方案在临床上具有相关性且有用，因为可以通过考虑影响手术过程和结果的多个因素来设计最佳手术入路，这些因素包括预期的粘连范围、复发的好发部位以及肿瘤的解剖位置。在对应于鞍内和视交叉前肿瘤的鞍膈下肿瘤中，即使存在相当程度的鞍上扩展，也可合理尝试经蝶入路，因为它们往往与鞍内结构粘连，并且通过牵拉肿瘤上表面可能容易与脑结构分离。然而，鞍膈上肿瘤可能需要更广泛的手术入路以提供对肿瘤的直接视野，因为可能存在广泛粘连。
