Craniopharyngioma 0: A New Addition to the Tumor Classification Scheme

Introduction: Craniopharyngiomas are challenging tumors that often require multimodal treatments due to their recurrence rate. As such, clinicians caring for patients with these lesions need multiple strategies for their management. To help formulate a surgical strategy, Kassam et. al published a seminal paper in 2008 describing a classification system for craniopharyngiomas based upon their location relative to the infundibulum. This proposed scheme organized these neoplasms into three categories: pre-infundibular (Type I), trans-infundibular (Type II), retro-infundibular (Type III) and isolated third ventricular or optic recess tumors (Type IV). In addition, the surgical corridor and the limitations of the endoscopic, endonasal approach (EEA) are discussed. Because purely sellar craniopharyngiomas were not elaborated upon in that publication, the authors will described their experience with purely intrasellar craniopharyngiomas.

Methods: The authors retrospectively reviewed the clinical presentation, radiographic features, intraoperative findings, and pathologic diagnosis for pure intrasellar craniopharyngiomas. The authors have obtained an IRB to review this data.

Results: The patients who obtained a final pathologic diagnosis of craniopharyngioma with an entirely sellar tumor were identified. The patient and tumor characteristics are described as separate cases and the patients’ endocrine function and post-operative course are noted as well to reveal any salient patterns that can be seen between cases. Because of their location, these tumors were entirely managed with EEA.

Conclusion: Craniopharyngiomas arise from squamous cell rests of the hypophyseal-pharyngeal duct found in the infundibulum and pituitary gland. The cases we have described suggest a subdiaphragmatic origin to a subset of these tumors that do no invade the suprasellar space. Therefore, the authors believe these tumors, which will be referred as Type 0 craniopharyngiomas, should be treated in a similar fashion to microadenomas or Rathke cleft cysts. An endoscopic, endonasal transsellar approach is sufficient for the surgical management.