Figure 2

We hypothesized from our intraoperative experience with pituitary tumors that some pituitary adenoma subtypes have a predilection for invading the medial wall of the cavernous sinus more so than others. Case examples of various pituitary adenomas with varying Knosp grade and invasion into the medial wall of the cavernous as viewed on preoperative MRI (T1 with gadolinium), through medical illustrations, from an endoscopic intraoperative view, and microscopically with histological H&E staining and immunocytochemistry. (A) Preoperative coronal MRI demonstrating a Knosp grade 1 corticotroph adenoma (B) A medical illustration of the intraoperative view from an endoscopic transsphenoidal approach after the adenoma has been removed and the pituitary gland remains displaced the left side of the field exposing an intact medial of the cavernous sinus with no evidence of invasion (C) An intraoperative view from an endoscopic transsphenoidal approach after the adenoma has been removed and the pituitary gland remains displaced the left side of the field exposing an intact right medial wall of the cavernous sinus with no evidence of invasion (D) Histological images of H&E slides of a resected medial wall with no evidence of invading pituitary adenoma cells (E) Histological images of immunohistochemistry slides of a resected medial wall with no evidence of invading pituitary adenoma cells (staining for T-pit transcription factor) (F) Preoperative coronal MRI demonstrating a Knosp grade 1 somatotroph adenoma (G) A medical illustration of the intraoperative view from an endoscopic transsphenoidal approach after the adenoma has been removed and the pituitary gland remains displaced to the left side of the field exposing the right medial wall of the cavernous sinus with subtle evidence of tumor invasion (H) An intraoperative view from an endoscopic transsphenoidal approach after the adenoma has been removed and the pituitary gland remains displaced the left side of the field exposing the right medial wall of the cavernous sinus with subtle evidence of tumor invasion (I) Histological images of H&E slides of the resected medial wall with evidence of invading pituitary adenoma cells (J) Histological images of immunohistochemistry slides of the resected medial wall in the case with evidence of invading pituitary adenoma cells (staining for Pit-1 transcription factor) (K) Preoperative coronal MRI demonstrating a Knosp grade 3 somatotroph adenoma (L) A medical illustration of the intraoperative view from an endoscopic transsphenoidal approach after the adenoma has been removed and the pituitary gland remains displaced to the left side of the field exposing the right medial wall of the cavernous sinus with frank evidence of tumor invasion (M) An intraoperative view from an endoscopic transsphenoidal approach after the adenoma has been removed and the pituitary gland remains displaced the left side of the field exposing the right medial wall of the cavernous sinus with frank evidence of tumor invasion (N) Histological images of H&E slides of the resected medial wall in this case with evidence of invading pituitary adenoma cells O. Histological images of immunohistochemistry slides of the resected medial wall in this case with evidence of invading pituitary adenoma cells (staining for Pit-1 transcription factor).