[Malignant peripheral nerve sheath tumor in the posterior mediastinum]

Low-Grade Malignant Peripheral Nerve Sheath Tumor: A Case Report of Exceptional Parapatellar Location in the Knee

Malignant tumors of the peripheral nerve sheaths are uncommon, constituting a small percentage, typically ranging from 2% to 5% of soft tissue sarcomas. Etiological diagnosis is often difficult but is guided by imaging and confirmed by histopathological and immunohistochemical examination. We report a case of a 46-year-old woman admitted for management of a mass in the medial parapatellar region of the right knee. Her medical history included a burn to the right leg five years ago and a previously undocumented resection of a medial parapatellar tissue mass in the right knee. Radiological examination showed a deep and superficial soft tissue mass in the medial soft tissue of the right knee opposite the patella, with no hemorrhagic components and heterogeneous enhancement after injection of gadolinium. Histopathology confirmed the diagnosis of a low-grade peripheral nerve sheath tumor, and a thoracic-abdominal-pelvic CT scan was performed, which was normal. Treatment consisted of a simple carcinological resection and local radiotherapy. No local recurrence was noted after one year of follow-up.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

[Malignant peripheral sheath nerve tumor: An exceptional mass of the anterior and middle mediastinum]

Malignant peripheral nerve sheath tumors (MPNST) are rare nervous tumors usually located in the posterior mediastinum in the paravertebral gutters. We report the case of a non-smoking 62-year-old man who was admitted with a 4 months history of cough, hoarseness and shortness of breath. Physical examination noted a superior vena cava syndrome. CT scan of the chest revealed a right anterior and middle mediastinal mass compressing the superior vena cava, the ascending aorta, the right pulmonary artery, invading the superior root of the pulmonary vein and the right auricle. Flexible bronchoscopy showed extrinsic compression of the right main bronchus, the right upper lobe bronchus and intermedius bronchus. The patient underwent surgical biopsy of the mass by mediastinoscopy. Histological examination revealed a malignant peripheral nerve sheath tumor. The patient received a single cycle of chemotherapy (ifosfamid-adriamycin). Clinical course was marked by the fast worsening of the dyspnea and the general state. Patient died three weeks after the cure of the chemotherapy. This case is original by the exceptional clinical presentation of MPSNT with a superior vena cava syndrome and the very rare location of this tumor in the anterior and middle mediastinum.

[Intrathoracic giant peripheral nerve sheath tumor during Von Recklinghausen disease]

We report the case of a patient aged 23, admitted for bilateral intrathoracic tumor, including a giant right. Surgery was performed by right sternothoracotomy. After 7 days, she presented an irreversible cardiac arrest. The malignant peripheral nerve sheath tumors are rare and aggressive. Their incidence is 0.001% in the general population and 0.16% in patients with neurofibromatosis type 1. These tumors are characterized by their risk of recurrence and poor prognosis. The treatment is the surgical resection. We analyze incidence, diagnosis and prognosis of these tumors.