The first malignant primary hepatic glomus tumor: A case report

INTRODUCTION: Glomus tumors (GTs) are rare neoplasms that originate from the modified smooth muscle cells of glomus bodies and occasionally arise from visceral primary sites. All previously reported primary hepatic GTs were benign. Here we report the first malignant primary hepatic GT. PRESENTATION OF CASE: Our patient is a 60-year-old male who presented with weight loss, early satiety, night sweats, and abdominal distention. Imaging demonstrated a large mass abutting the stomach, duodenum, and head of the pancreas, exerting mass effect on the portal vein and inferior vena cava. Biopsy results were deemed nondiagnostic after extensive review at multiple academic institutions. We performed a caudate lobe resection, antrectomy, and Bilroth II gastrojejunostomy that required skeletonization of much of the periportal vascular anatomy and the repair of multiple venotomies due to the tumor’s adherence to the inferior vena cava. Histopathologic evaluation revealed morphologic and immunohistochemical findings consistent with a malignant GT, and next-generation sequencing using a targeted panel revealed an inactivating TP53 mutation. DISCUSSION: This case presented both a surgical and histopathologic challenge, requiring meticulous operative technique for resection in conjunction with a combination of characteristic morphologic features and immunohistochemical staining for diagnosis. Sequencing results using a targeted panel add to the limited GT genomic literature. CONCLUSION: While rare, it is important to consider malignant GTs in the differential diagnosis for heterogeneous liver masses. Close follow-up will be essential to monitor our patient’s clinical course and expeditiously pursue any further interventions.