Fig. 1. A typical suprasellar craniopharyngioma with solid and cystic components. T1 sagittal MRI with gadolinium enhancement.
Visual dysfunction from chiasmatic or optic nerve compression occurs in patients of all ages, although children are more tolerant of, or more difficult to test for, visual field deficits. Cognitive symptoms in the form of memory loss, dementia, and psychiatric symptoms occur less frequently and are seen primarily in adults. Elevations in ICP, usually as the result of obstructive hydrocephalus, are common. Accordingly, headache, vomiting, papilledema, ataxia, and, rarely, cranial nerve palsies may all be additional presenting features.
All patients should have a comprehensive endocrine evaluation. Visual performance should be documented with fundoscopic examination, tangent screen, and perimetry. With computed tomography (CT) or magnetic resonance imaging (MRI), craniopharyngiomas typically appear as inhomogeneous lesions—ones in which cystic components can often be discerned from solid elements. Calcification is often present and can be a helpful diagnostic clue.
In newly diagnosed patients, maximum safe tumor resection is often a reasonable initial goal. In many instances, this can be achieved via craniotomy, although in selected cases transsphenoidal resection provides safer access. In others, complete excision requires a combination of both approaches. Tumors without sellar enlargement generally arise and remain suprasellar, and therefore are best managed by a transcranial (pterional, subfrontal, or anterior interhemispheric) route. When using any of these corridors of access, third ventricular components of the tumor can be exposed and resected by opening the lamina terminalis. When confronted with a wholly third ventricular tumor, particularly if solid and densely calcified, a transcallosal approach to the third ventricle may be necessary. During the course of tumor resection, it usually becomes evident whether complete removal is a safe and feasible strategy. Aggressive attempts to remove tumor fragments that are tenaciously adherent to neural and vascular structures are accompanied by a wholly unacceptable functional cost. Alternatively, other tumors are less adherent and complete excision can be safely achieved.
As a rule, craniopharyngiomas associated with sellar enlargement can be regarded as subdiaphragmatic. Even though such tumors may exhibit significant intracranial extension, they invariably maintain an "extra-pial" and "extra-arachnoid" disposition. Accordingly, they remain amenable to complete excision via a transsphenoidal route (9,10). An interim analysis of experience with transsphenoidal management of craniopharyngiomas (1973-1996) included 138 patients (7). Of these, 86 cases had involved primary operative attempts, with gross total removal the goal in virtually all. The remaining patients had been treated for palliation with goals of partial removal and decompression of cystic components. Collectively, the outcome for these patients has been satisfactory, with 82% of patients enjoying symptom-free survival at 5 or more years. Comparable results have been reported by others, particularly with regard to the primary use of transsphenoidal surgery for craniopharyngiomas (11-14). Complete resection can be achieved in the majority of patients, and recurrence rates thereafter are less than 10%. Improvements in visual loss can be expected in the majority of affected patients. As mentioned, preservation of endocrine function is a major limitation of the transsphenoidal approach in this disease, with deterioration in anterior pituitary function reported in as many as 79% of treated patients and new onset DI occurring in up to half (14). Still, when considered from the standpoints of survival, quality of life, recurrence rate after total removal, mortality, and morbidity, the results of transsphenoidal resection have been comparable to, and in most instances superior to, results reported in patients treated by cran-iotomy. This is especially true from the standpoint of recurrence, because several authors have commented on the significantly lower rate of recurrence of cran-iopharyngiomas amenable to transsphenoidal resection as compared with those patients who required transcranial procedures (11-14). The difference is due to patient selection and reflects the fact that candidates suitable for transsphenoidal surgery are more likely to harbor tumors amenable to total removal than are the remaining population of craniopharyngiomas.
The prognosis of craniopharyngiomas depends, in large measure, on the completeness of tumor resection. For completely excised lesions, no adjuvant therapy is required. The outlook for these patients is favorable, although late recurrence occurs in as many as 25% of patients despite "total" removal. For incompletely resected tumors, symptomatic recurrence is virtually guaranteed; thus, radiation therapy is indicated to forestall recurrence. In one recent series, "radical subtotal resection" followed by radiotherapy provided progression-free survival in 91% of patients during a mean follow-up period of 4 yr (15). In attempting to isolate the efficacy of microsurgical management alone, Yasargil et al. reported a 90% rate of complete resection among 144 patients and a recurrence rate of 7%; the period of follow-up was not specified (16). In this series, 67% of patients experienced a "good" outcome; however, operative morbidity and overall mortality were 16% and 16.7%, respectively. Fahlbusch et al. reported their experience with 168 patients, followed for a mean period of almost 6 yr (12). In this report, gross total resection was achieved in approx half of all patients, leading to a cumulative recurrence-free survival of 87% and 81% at 5 and 10 yr, respectively. Of patients in whom only subtotal or partial resection could be achieved, the 5-yr recurrence-free survival dropped to 49% and 42%, respectively; approx 30% of patients received radiation therapy at some point in their course. The Mayo Clinic recently reported its long-term outcomes for 121 patients followed for a mean of 10 yr (6). In this report, gross total resection could be achieved in 69 of 121 (57%) patients. Radiologic recurrence/regrowth occurred in 24% of patients. Using a variety of outcome measures, "good outcomes" were achieved in approx 60% of patients. Among others, factors associated with poor outcomes included lethargy at presentation, visual loss, and hydrocephalus. Gross total resection favorably affected outcome and rate of recurrence, with the latter also being reduced by postoperative radiotherapy.
The management of the recurrent craniopharyngioma is more complex, because therapeutic goals must be especially well defined (2,7,8,10,17). In some cases, and despite the technical demands of reoperation, total resection can still be achieved. However, for many recurrent tumors, palliative surgery is often the most realistic goal. Recurrent lesions with a significant cystic component can often be treated by repeat aspiration. This can be achieved by inserting a silastic tube attached to an Ommaya reservoir into the cyst cavity. Alternatively, the transsphenoidal insertion of a silastic tube from the tumor cavity into the posterior nasal space can provide prolonged drainage. In addition to conventional irradiation, there are several other radiotherapeutic options applicable for recurrent tumors (18,19). For cystic lesions, intracavitary instillation of radioactive solutions containing colloidal phosphorus, yttrium, or gold has been of benefit. Solid recurrences have been treated with interstitial brachytherapy (the irradiation of lesions by insertion of an isotope within the tumor) and stereotac-tic radiosurgery.
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