3477 Preoperative localization of neuroendocrine tumors of the pancreas with eus-guided fine needle tattooing.

Abstract

Background: Neuroendocrine tumors of the pancreas are rare. Various imaging modalities are employed preoperatively to assist in the diagnosis and localization of these tumors. However, surgeons usually have to perform manual palpation of the pancreas and peripancreatic tissues in addition to intraoperative ultrasound to localize these tumors, especially when they are small and difficult to visualize. Aim: The purpose of this ongoing study is to demonstrate the role and safety of EUS-guided fine needle tattooing (FNT) of these tumors so they can be identified more easily at the time of surgery. Methods: Two patients with clinical and biochemical evidence of neuroendocrine tumors who failed localization with routine imaging modalities were referred for EUS. After localizing and staging each tumor, EUS-guided FNA was performed for tissue diagnosis followed by the injection of sterilized India ink within the lesions. The injection needle was initially purged with the India ink outside the lesion so as not to inject air, which may attenuate visualization of the tumor. No antibiotics were given before or after the procedure. Results:One patient with insulinoma (48 y/o, F) underwent EUS-FNT. At laparotomy the tattooed tumor was readily seen. Manual palpation and intraoperative ultrasound further proved it. No India ink was seen outside the tumor. The resected specimen confirmed that the tattooed area contained the insulinoma. The second patient (76 y/o. M) was diagnosed with a carcinoid tumor located in the peripancreatic region near the head of the pancreas. This patient also underwent EUS-FNT but refused surgery. Both patients did well post-procedure with no evidence of infectious complications. Conclusion: EUS-FNT is a promising new technique that may aid in the preoperative localization of neuroendocrine tumors and perhaps be cost effective. It might be of great importance in the era of laparoscopic enucleation of neuroendocrine tumors that has recently been described. A multi center study is warranted for further evaluation. Background: Neuroendocrine tumors of the pancreas are rare. Various imaging modalities are employed preoperatively to assist in the diagnosis and localization of these tumors. However, surgeons usually have to perform manual palpation of the pancreas and peripancreatic tissues in addition to intraoperative ultrasound to localize these tumors, especially when they are small and difficult to visualize. Aim: The purpose of this ongoing study is to demonstrate the role and safety of EUS-guided fine needle tattooing (FNT) of these tumors so they can be identified more easily at the time of surgery. Methods: Two patients with clinical and biochemical evidence of neuroendocrine tumors who failed localization with routine imaging modalities were referred for EUS. After localizing and staging each tumor, EUS-guided FNA was performed for tissue diagnosis followed by the injection of sterilized India ink within the lesions. The injection needle was initially purged with the India ink outside the lesion so as not to inject air, which may attenuate visualization of the tumor. No antibiotics were given before or after the procedure. Results:One patient with insulinoma (48 y/o, F) underwent EUS-FNT. At laparotomy the tattooed tumor was readily seen. Manual palpation and intraoperative ultrasound further proved it. No India ink was seen outside the tumor. The resected specimen confirmed that the tattooed area contained the insulinoma. The second patient (76 y/o. M) was diagnosed with a carcinoid tumor located in the peripancreatic region near the head of the pancreas. This patient also underwent EUS-FNT but refused surgery. Both patients did well post-procedure with no evidence of infectious complications. Conclusion: EUS-FNT is a promising new technique that may aid in the preoperative localization of neuroendocrine tumors and perhaps be cost effective. It might be of great importance in the era of laparoscopic enucleation of neuroendocrine tumors that has recently been described. A multi center study is warranted for further evaluation.