Malignant Nerve Sheath Tumor (MPNST) in the Middle Mediastinum

Abstract

SESSION TITLE: Global Case Report Poster - Lung Cancer SESSION TYPE: Global Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: The incidence of MPNST is 0.001% in the general population. Although MPNST can be found in any part of the body including extremities, head and neck, trunk, or retroperitoneum, intrathoracic MPNST with or without NF1 is uncommon, only with several reported adult cases. We report a very rare case of MPNST presenting as an middle mediastinal mass treated by surgical excision. CASE PRESENTATION: A 29 year old non smoker woman with no previous history of pulmonary tuberculosis complained of difficulty of breathing that started one month prior to admission. The condition was associated with chest discomfort and easy fatigability which were relieved by rest. On examination, she was not in respiratory distress. Occasional fine crackles on lower lung fields were noted during chest and lung examination. She sought consult where a chest xray was done revealing a soft tissue density seen in the right hilar area considering a mediastinal mass. Eventually chest CT scan was requested which confirmed the presence of a 7 x 6 cm heterogenous mass located in the middle mediastinum with massive pericardial effusion and minimal pleural effusion. A pericardiostomy tube was initially inserted and eventually an excision of middle mediastinal mass was done. A 6 x 5 cm middle mediastinal mass was seen extending from the anterior surface of the superior vena case insinuating between the medial aspect of the SVC at the aorta. Biopsy revealed a malignant peripheral nerve sheath tumor with focal muscle differentiation. On the 8th hospital day, patient was discharged improved. DISCUSSION: MPNST is also known as malignant schwannoma, neurofibrosarcoma and neurogenic sarcoma. More than 50% patients with MPNST have NF1 with a reported five year survival of 15%. Histopathological examination remains the mainstay to arrive at the diagnosis of the malignant nature of schwannoma. CONCLUSIONS: MPNST is considered as one of the most important neurogenic tumor. Our patient presented with a MPNST in the middle mediastinum which is considered as a rarefied case. The possibility of nerve sheath tumor should be taken into consideration even if it is not manifest in the posterior mediastinum. Reference #1: Malignant peripheral nerve sheath tumor of the anterior mediastinum: a rare presentation. Babusha Kalra, Pamela Alice Kingsley, Harinder Singh Bedi, Kanwardeep Singh Kwatra, Preeti Negi, Rare Tumors 2014; volume 6:5528. Reference #2: Huge Intrathoracic Malignant Peripheral Nerve Sheath Tumor in an Adolescent with Neurofibromatosis Type 1. Yoon Et al. Case Reports in Pediatrics Volume 2014. Reference #3: Mesenchymal tumours of the mediastinum—part II. Michael A. den Bakker & Alexander Marx & Kiyoshi Mukai & Philipp Ströbel, Virchows Arch (2015) 467:501-517 DISCLOSURE: The following authors have nothing to disclose: Mark Janiel Cacanindin No Product/Research Disclosure Information