Reconstruction of rare skull metastases using free latissimus dorsi flap and the role of preoperative embolization in hypervascular skull tumors

Metastatic tumors are the most common cranial neoplasms in adults. Skull metastases from rare primary tumors, such as cholangiocarcinoma or pancreatic neuroendocrine tumor, are extremely uncommon and rarely reported. Given the scarcity and variation of these rare skull metastases, treatments and outcomes of such patients are of interest to treating surgeons. The authors describe the treatment algorithm, course, and outcomes of 2 patients with rare gastrointestinal skull metastases. The first patient had intrahepatic cholangiocarcinoma metastatic to the skull, while the second patient developed a solitary skull metastasis secondary to a pancreatic neuroendocrine tumor. As part of this report, the authors include a literature review of rare skull metastases as well as the treatment of these 2 patients. Both the patients ultimately underwent successful resection of the tumor for relief of their clinical symptoms. Wide resections in both patients necessitated reconstruction using a free latissimus dorsi muscle flap in both the patients. Preoperative embolization of the hypervascular cholangiocarcinoma skull metastasis was performed prior to resection in the first patient. To date, there have been only 4 such reports of skull metastases from intrahepatic cholangiocarcinoma and limited reported cases of isolated skull metastases from a pancreatic neuroendocrine tumor. In patients with large or numerous skull metastasis from rare primary tumors, surgical resection should be considered for symptomatic improvement. In cases of hypervascular lesions, preoperative embolization can be considered to decrease the intraoperative bleeding. Free tissue transfers using myocutaneous flaps such as latissimus dorsi help in obliterating dead space, and creating a healthy soft tissue envelope to withstand postoperative radiation treatment. In addition, a chimeric flap can be designed to include additional muscle or soft tissue to obliterate and exclude the sinus cavities.