St. Elizabeth's Medical Center, Tufts University School of Medicine Brighton, MA, United States
Padmavathi Srivoleti, MD1, Erik Holzwanger, MD2, Svetlana Kondratiev, MD1, Sandeep Krishnan, MD, PhD1 1St. Elizabeth's Medical Center, Tufts University School of Medicine, Brighton, MA; 2Tufts University Medical Center, Brighton, MA
Introduction: Pancreatic leiomyosarcomas (PLMS) are rare mesenchymal tumors accounting for 0.1% of all pancreatic tumors. Untreated PLMS have poor prognosis, with a 5-year mortality rate of 77.8%. Pathologic tissue diagnosis is imperative for diagnosis and treatment. The heterogenous consistency of the mass can make EUS guided biopsy challenging. Here we report a case of EUS-guided biopsy of primary PLMS of pancreas.
Case Description/Methods: 73-year-old man with no past medical history underwent a transabdominal ultrasound for evaluation of abdominal aortic aneurysm. He was incidentally noted to have a 4.7 cm x 3.3 cm hypoechoic heterogenous mass at the level of bifurcation of aorta. Additionally, multiple hypoechoic lesions were noted in the liver. A CT abdomen/pelvis with contrast revealed a heterogenous mass with central necrosis in the inferior aspect of the pancreatic head. There was no evidence of extrahepatic or intrahepatic biliary ductal dilatation. Furthermore, a soft tissue was nodule noted in the gluteus maximus muscle. An endoscopic ultrasound (EUS) was performed with a linear echoendoscope that revealed a 4cm x 4 cm irregular mass in the pancreatic head, borders of which were poorly defined. The pancreatic duct and remaining parenchyma were otherwise unremarkable. Additionally, multiple hypoechoic, irregular masses were noted in the left lobe of the liver. EUS based TNM staging was T3N0M1. Fine needle biopsy of the pancreatic and liver lesions was performed with a 22G core biopsy needle. Pathology was remarkable for spindle cells with eosinophilic fibrillary cytoplasm, nuclear atypia, and frequent mitosis. Immunohistochemical stains were positive for desmin, smooth muscle actin, vimentin and negative for CD34, pankeratin, S100, and C-Kit consistent with leiomyosarcoma. He is planned for chemotherapy with gemcitabine and Taxotere.
Discussion: Primary pancreatic leiomyosarcomas are challenging to diagnose and carry a poor prognosis. They are heterogenous in consistency, ranging from solid (53%), cystic (16%) to mixed (31%). Imaging studies fail to distinguish PLMS from other pancreatic tumors. Diagnosis is often established after surgical resection. In this case, we note that EUS is a valuable modality that provides a minimally invasive approach in establishing accurate histological and immunohistochemical diagnosis of this rare, but aggressive tumor. Further management involves surgical resection with tumor free margins and chemotherapy with gemcitabine plus paclitaxel in unresectable cases.
Figure: Figure 1: Panel A: EUS image of an irregular mass in the pancreatic head with poorly defined borders. Panel B: EUS image of fine needle biopsy of the pancreatic lesions that was performed with a 22G core biopsy needle. Panel C: Pathology of pancreatic mass showing spindle cell neoplasm with smooth muscle differentiation. Spindle cells demonstrate eosinophilic fibrillary cytoplasm, marked nuclear atypia and frequent mitoses (5/10 HPF). Panel D: Immunohistochemical staining demonstrates strong and diffuse immunoreactivity for Desmin in tumor cells.
Disclosures: Padmavathi Srivoleti indicated no relevant financial relationships. Erik Holzwanger indicated no relevant financial relationships. Svetlana Kondratiev indicated no relevant financial relationships. Sandeep Krishnan indicated no relevant financial relationships.
Padmavathi Srivoleti, MD1, Erik Holzwanger, MD2, Svetlana Kondratiev, MD1, Sandeep Krishnan, MD, PhD1. P2207 - A Case of Primary Pancreatic Leiomyosarcoma: An EUS Diagnosis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.
