Massive Intrathoracic Malignant Peripheral Nerve Sheath Tumor with Tracheobronchial Obstruction Bryan Barnosky, DO; and ArunabhTalwar MD. North Shore University Hospital, Manhasset, NY. Division of Pulmonary and Critical Care Medicine.

Case Presentation 23 year old male with progressive dyspnea for approximately one month. Subjective fever, sore throat, and a non-productve cough. Right sided chest pain, night sweats, and a 10 – 15 lb. unintentional weight loss. No significant medical or surgical history. Non-smoker.

Case Presentation Vital signs: T 36.3, HR 100, RR26, BP 132/67, and SaO2 96% on room air. Mild respiratory distress at rest. Physical examination revealed markedly diminished breath sounds over the right hemithorax and tenderness to palpation of the right lateral chest wall.

Laboratory Data WBC 9700 Hgb 12.9 Hct 38.7 Platlets 387000 PT 14.4 INR 1.27 PTT 26.7 ESR 77 LDH 1092 Na 136 K 3.4 Cl 104 CO2 26 BUN 4 Cr 0.7 AST 44 ALT 15 Alk Phos 77

Hospital Course The patient’s respiratory status progressively worsened and he was taken to surgery for exploration and biopsy. The mass was deemed unresectable and post-operatively the patient remained on the ventilator. Subsequent weaning trials were unsuccessful and the patient underwent bronchoscopy to evaluate the utility of endobronchial stenting.

Bronchoscopy Extrinsic compression of the distal trachea and right mainstem bronchus with resultant collapse of the the right middle and lower lobes. Extrinsic compression of the left mainstem bronchus at the carina and extending approximately 1.5cm distally.

Bronchoscopy The left mainstem bronchus was dilated to 13.5mm via balloon. Under fluoroscopic guidance an Ultraflex distal release, covered stent was placed. Post-procedure the left mainstem bronchus and all distal segments were completely patent.

Hospital Course The patient was weaned from the ventilator the following day. The final pathological diagnosis was malignant peripheral nerve sheath tumor. The patient was then transferred to another facility for the initiation of chemotherapy. Shortly thereafter the patient’s condition rapidly deteriorated and he expired.

H & E

S-100

Thoracic Neurogenic Tumors Neurogenic tumors of the thorax can arise from any tissue of the neural crest (peripheral, autonomic, or paraganglionic nervous systems). Most commonly found in the costovertebral sulcus arising from the sympathetic chain or one of the rami of the intercostal nerves. These tumors are most often asymptomatic although infrequently dyspnea, cough, or other respiratory symptoms may be noted. In adults, the malignancy rate of neurogenic tumors is less than 10% (and probably only 1 to 2%).

Malignant Peripheral Nerve Sheath Tumors Spindle cell sarcoma arising from a nerve, neurofibroma, or demonstrating nerve tissue differentiation. Previously referred to as malignant schwannoma, neurogenic sarcoma, and neurofibrosarcoma. Estimated frequency in the general population is 0.001% compared with 2 to 5% in patients with Neurofibromatosis type I.

Malignant Peripheral Nerve Sheath Tumors Histological analysis reveals unencapsulated infiltrating tumors composed of spindle cells arranged in a sweeping fascicles with densely cellular areas alternating with less cellular ones. Mitotic figures are readily visible and 50-90% of cases are immunoreactive with S-100 protein staining. Highly malignant, locally invasive and with a high likelihood of producing local recurrence and distant metastasis. Surgical resection with postoperative radiation and/or chemotherapy is the usual mode of treatment.

Indications For Endobronchial Stents Intrinsic airway obstruction from benign or malignant diseases. Extrinsic stenosis of central airways from benign or malignant diseases. Sealing of airway fistulas. Tracheobronchial malacia. Complex, inoperable tracheobrochial strictures.

CONCLUSION Although relatively rare, malignant peripheral nerve sheath tumors must be included in the differential diagnosis of a massive intrathoracic mass. While ultimately not improving outcome, we believe that the endobronchial stenting procedure performed in this case did facilitate weaning from the ventilator which improved our patient’s quality of life.