Craniopharyngioma: A pathologic, clinical, and surgical review

Craniopharyngioma is a rare and mostly benign epithelial tumor of the sellar and suprasellar region. Two principal patterns of craniopharyngioma are recognized: papillary and adamantinomatous. Papillary craniopharyngiomas are encountered in adults and may lack the cystic spaces filled with "motor oil" as well as the palisading peripheral rows of epithelial cells, keratinization, or calcification typical of pediatric adamantinomatous craniopharyngioma. Secondary to their anatomic location, craniopharyngiomas may present with endocrinologic dysfunction and visual disturbances. Differential diagnosis includes Rathke's cleft cyst, pituitary adenoma, dermoid/epidermoid cysts, and other rare sellar/suprasellar lesions as pituicytomas. Many controversies exist concerning the preferred surgical approach for these tumors. Endoscopic endonasal surgery is no longer reserved only for sellar or small cystic suprasellar lesions. Prechiasmatic/preinfundibular lesions are effectively removed using an endonasal transtuberculum/ transplanum approach; subchiasmatic/transinfundibular tumors require the addition of a transellar approach with inferior pituitary transposition; and retrochiasmatic/ retroinfundibular lesions are better accessed performing an endonasal superior pituitary transposition. Compared with well-established trancranial approaches (pterional, subfrontal, presigmoid), endoscopic endonasal surgery combines the virtues of the caudocranial and midline approaches, allowing for appropriate infrachiasmatic exposure without the need for manipulation of surrounding neurovascular structures to access the tumor. This anatomic advantage, combined with high-definition wide-angle visualization, exquisite endonasal microsurgical techniques, and devoted instrumentation facilitates a high rate of endocrine function preservation and visual improvement, while concurrently achieving comparable resections. Endoscopic skull base reconstruction with the vascularized nasoseptal flap has dramatically reduced the incidence of cerebrospinal fluid leak, consolidating endoscopic endonasal surgery as an effective and safe alternative for the treatment of these challenging tumors.