Removal of a Frontal Sinus Osteoma and Reconstruction by a Custom-Made Implant with Neuronavigation Assistance.

The authors report the surgical treatment of an extensive right frontal sinus osteoma assisted by neuronavigation and reconstruction by a hydroxyapatite custom-made implant. The patient presents with ptosis, hypoglobus, and proptosis of the right eye, without any visual impairment. Computed tomographic (CT) scan showed a very large bony mass involving right frontal sinus and displacing the orbital roof. A stereolithographic model-guided planning was carried out to obtain a practical simulation of the surgical operation and it was submitted to a new CT scan to acquire the reference point to realize the neuronavigation assistance, and to achieve the template to realize the hydroxyapatite custom-made implant. Intraoperatively, with the help of neuronavigation assistance, osteotomies were performed by piezoelectric device. The reconstruction was made using a hydroxyapatite custom-made implant. The procedure was damage free, the bony mass was excised, and the orbital roof was repaired without any adverse effects. Postsurgical CT scan and scintigraphy showed a good reconstruction and a good-quality osteoblasts activity on the borders of the implant. Osteoma is a benign slow-growing bone tumor, usually involving the frontal sinus. Navigational assistance offers a very important help to perform safe osteotomies. Hydroxyapatite custom-made implant seems to be an excellent reconstructive method.

Thyroid as a target of metastases. A case of foregut neuroendocrine carcinoma with multiple abdominal metastases and a thyroid localization after 21 years.

The thyroid gland is quite often the target of metastases. For this reason any thyroid nodule in a patient with a previous history of cancer needs to be evaluated. In case of thyroid metastases, the site of the primary tumor is most often the breast, lung or kidney. A thyroid metastasis from a foregut neuroendocrine tumor is very unusual and requires a differential diagnosis with primary neuroendocrine tumor of the gland itself, i.e., a medullary thyroid carcinoma. This case report is peculiar because of the multiple sites of abdominal relapses, the long time interval between relapses (21 years), and the positive outcome after surgical treatment.