Primary Intrathoracic Neurogenic Tumors: Clinical, Pathological, and Long-Term Outcomes

Challenging Diagnosis: Unmasking the Enigma of Imaging Findings with Lung Schwannomas

Schwannomas are benign slow-growing tumors arising from the embryonic neural crest cells of the nerve sheaths of peripheral and cranial nerves, and they are a rare type of soft tissue mass that is usually always solitary. Generally, it grows in the head, neck, and flexor portions of the limbs, where many nerves are located. Schwannomas of the lung are extremely rare. Fewer than ten cases of schwannomas in this organ region have been reported in the existing literature. In this case report, a 40-year-old male non-smoker was hospitalized with occasional chest pain. His chest computed tomographic scan revealed a 3.8 cm space occupying lesion in the upper lobe of the right lung. This lesion has clear boundaries and uneven internal density. And it was concluded as a benign lesion possibility, it is preferred to be considered as a haematoma. This space occupying lesion was eventually confirmed as a schwannoma by needle biopsy tissues. Due to the presence in rare locations, such as the lung, the clinical presentation of this space occupying lesion is non-specific, making diagnosis difficult. The data presented in this case report can help clinicians to obtain information on the identification of this disease, which highlighted lung schwannoma as a differential diagnosis for patients with intermittent pain. It can also alert clinicians and radiologists to observe every detail of the radiology imaging findings.

Chylothorax After Schwannoma Resection

Schwannomas are tumors derived from Schwann cells of the peripheral nerve sheath that are usually benign; nonetheless, they can cause significant morbidity. When indicated, surgical resection is the gold standard of treatment for schwannomas. However, chylothorax is a rare postoperative complication of thoracic surgery. We present a case of chylothorax after thoracic schwannoma resection. A 61-year-old woman underwent a computed tomography (CT) scan for suspected nephrolithiasis, which instead found a right mediastinal mass that was confirmed to have features consistent with a schwannoma on thoracic spine magnetic resonance imaging (MRI). Right thoracotomy and schwannoma resection were performed, resulting in the complete removal of the schwannoma without capsular invasion. Two chest tubes were also inserted. On postoperative day 1 (POD1), the patient presented with a chylothorax that was initially treated with chest tube suctioning and total parenteral nutrition (TPN). However, a repeat right thoracotomy with thoracic duct ligation and dry talc chemical pleurodesis was subsequently performed on POD15 due to a lack of clinical improvement, which saw the resolution of the chylothorax without recurrence. Chylothorax is a rare but severe postoperative complication of thoracic surgeries, including those that involve tumor resections. We present a case of chylothorax after thoracic schwannoma resection that initially failed conservative management but eventually resolved after thoracic duct ligation and chemical pleurodesis. This case highlights the need for effective non-surgical treatments for chylothorax, the importance of remaining vigilant for rare postoperative complications, and the need for randomized controlled trials (RCTs) to develop a standardized chylothorax management algorithm.

Benign Neurogenic Tumors

Neurogenic tumors arise from cells of the nervous system. These tumors can be found anywhere along the distribution of the sympathetic and parasympathetic nervous system and are categorized based on cell of origin: ganglion cell, paraganglion cell, and nerve sheath cells. Ganglion cell-derived tumors include neuroblastomas, ganglioneuroblastomas, and ganglioneuromas. Paraganglion cell-derived tumors include paragangliomas and pheochromocytomas. Nerve sheath cell-derived tumors include schwannomas (neurilemmomas), neurofibromas, and neurofibromatosis. Most of these are benign; however, they can cause local compressive symptoms. Surgery is the mainstay of treatment, if clinically indicated. Nonetheless, a thorough preoperative workup is essential, especially for catecholamine-secreting tumors.

Endobronchial ultrasound-guided transbronchial needle aspiration as a diagnostic modality for schwannoma: A case report

INTRODUCTION

Schwannomas are the most common nerve sheath tumors in the paravertebral mediastinum. Although radiological imaging is helpful in diagnosing schwannomas, a definitive diagnosis is dependent on pathological features of a surgical specimen. For patients who require preoperative diagnosis, an incisional biopsy using minimally invasive surgery is preferred. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is less commonly used for suspected schwannomas.

PATIENT CONCERNS

A 48-year-old woman presented to the clinic with complaints of productive cough for >1 month, expectorating yellow and mucoid sputum approximately 4 to 5 times per day. Chest computed tomography revealed a well-circumscribed, homogeneous, soft tissue mass lesion in right upper posterior mediastinum, measuring 55 mm × 44 mm. Vocal fremitus in the right upper lung was diminished, the percussion note was slightly dull, and breath sounds were slightly reduced on auscultation. The patient was a nondrinker and nonsmoker, with no other relevant medical history. There was no significant relevant family medical history.

DIAGNOSIS

Complete blood count and blood biochemistry were within normal limits, except for an elevated erythrocyte sedimentation rate (32 mm/h). EBUS-TBNA was performed and histopathological findings were consistent with schwannoma.

INTERVENTIONS

The patient underwent schwannoma excision by thoracoscopy. Pathological findings from the surgical specimen were consistent with the EBUS-TBNA results. Based on EBUS-TBNA and postsurgical pathology, the patient was diagnosed with a right upper mediastinal schwannoma (Antoni B).

OUTCOMES

The patient experienced an uneventful postoperative recovery with no adjuvant therapy and was discharged on April 18, 2017. The patient has been followed up for 4 years and has not experienced any symptoms.

CONCLUSIONS

Cell blocks obtained from EBUS-TBNA afford the possibility of cytological examination and immunocytochemical staining, which can confirm diagnosis of schwannoma.