MALIGNANT PERIPHERAL NERVE SHEATH TUMOR SPREAD TO THE THORACIC CAVITY CAUSING OBSTRUCTIVE SHOCK

Abstract

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive subtype of sarcoma, which originates from peripheral nerves. MPNST can present sporadically or in association with neurofibromatosis type 1 (NF1). In this case we describe a patient with a rare spread of MPNST to her thoracic cavity resulting in a combination of obstructive and septic shock leading to death. CASE PRESENTATION: A 30 year old female with NF1 and MPNST presented with right flank pain of 5 days duration. The patient was found to have leukocytosis in the setting of hydronephrosis and was subsequently admitted. She quickly decompensated, becoming tachycardic and hypotensive. Computed tomography angiography of the abdomen and pelvis revealed severe hydronephrosis secondary to large abdominal mass effect and intrathoracic mass extending into the right middle lobe of the lung with invasion of the right and left atrium. Subsequently, she was transferred to the medical intensive care unit for mixed obstructive and septic shock requiring intubation and vasopressor support. Transthoracic echocardiogram revealed a small left ventricle cavity and an echogenic density 1.96 x 2.75 cm compressing the left atrium which appeared to be mass effect from the intrathoracic sarcoma. While awaiting hospice placement, she became bradycardic and was unable to be resuscitated, and ultimately succumbed to her condition. DISCUSSION: MPNST is defined as malignant tumors arising from peripheral nerves or as benign neurogenic tumors converted into malignant tumors. Although MPNST primarily affects extremities, it can rarely also occur in the thoracic cavity. The majority of MPNST occur on the right side of the heart, in close proximity to the interatrial septum, likely because of the origin of MPNST from cardiac branches of the vagus nerve and cardiac plexus. However, the presence of MPNST on the left side has also been reported. As with this patient, patients with Neurofibromatosis type I carry an increased risk for MPNST between 8-13%. In this case, the significant and severe spread of this patient’s MPNST caused multiple obstructions in the urinary system as well as within the heart, ultimately leading to the mixed shock. The most effective treatment for MPNST is complete excision, which unfortunately is not always possible in advanced stages. CONCLUSIONS: MPNST can be very difficult to treat due to its aggressive nature leading to terrible complications including obstruction and early death. In this case, the patient not only had MPNST, but also an even rarer spread to the thoracic cavity ultimately leading to her death. It is important to recognize that this disease process can escalate to a shock state and must be treated accordingly. Whenever possible, palliative care should be involved in patient care early to establish goals of care. Reference #1: Evans DG, Baser ME, McGaughran J, et al. Malignant peripheral nerve sheath tumours in neurofibromatosis 1. J Med Genet 2002; 39:311. Reference #2: Li S, Qiu Y, Yu J, Liang C, Peng L. Cardiac malignant peripheral nerve sheath tumor on computed tomography and magnetic resonance imaging: A case report. Medicine (Baltimore). 2019;98(44):e17463. doi:10.1097/MD.0000000000017463 Reference #3: Prifti E, Baboci A, Ikonomi M. A giant cardiac malignant peripheral nerve sheath tumor presenting with total obstruction of the superior vena cava. Ann Thorac Surg. 2014;97(1):e7-e9. doi:10.1016/j.athoracsur.2013.08.044 DISCLOSURES: No relevant relationships by Christopher Izzo, source=Web Response No relevant relationships by Nimeh Najjar, source=Web Response No relevant relationships by Spencer Streit, source=Web Response