Possibility of calcification of type I collagen matrix in growth hormone-secreting pituitary neuroendocrine tumor.

Background: In acromegaly caused by growth hormone (GH)-secreting pituitary neuroendocrine tumor (PitNET), excessive secretion of GH and insulin-like growth factor 1 (IGF-1) enhances bone anabolic effects while inducing the production of type I collagen, leading to increased bone mass and bone mineral density. We investigated the possibility of calcification of type I collagen matrix used in endoscopic transsphenoidal surgery (ETSS) for GH-secreting PitNET. Methods: Twelve patients with GH-secreting PitNET who underwent ETSS and were followed up for more than 1 year after surgery were divided into two groups: The "DuraGen group," in which DuraGen, a type I collagen matrix, was used as the overlay graft to cover the closed sella turcica for sellar floor reconstruction after tumor resection and the "fat group," in which fat was used. Clinical characteristics associated with surgery for GH-secreting PitNET were compared between the groups. Results: Seven patients were assigned to the DuraGen group and five to the fat group. One year after surgery, the reconstructed sellar floor was thickly calcified in all cases in the DuraGen group, but not calcified in all cases in the fat group. Patient characteristics, tumor-related factors including image findings, tumor size, histopathology and extent of tumor resection, and the pre- and postoperative course of GH and IGF-1 demonstrated no significant differences between the groups. Conclusion: In ETSS for acromegaly due to GH-secreting PitNET, the possibility of calcification of type I collagen matrix used as the overlay graft for sellar floor reconstruction should be considered.