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.