Mediastinal schwannoma: A case report

Abstract

Introduction

Mediastinal schwannoma is a rare tumor that develops from a peripheral nerve sheath in the mediastinal.

Case presentation

An Indonesian female, 60 years old, complained of breathlessness, left chest pain, and an intermittent cough. A cystic lesion in the left lung was discovered on radiological evaluation and no evidence of malignancy or metastases were found. The patient underwent a thoracotomy and continued therapy, which included cefixime at a dose of 2 × 200 mg/day, ketorolac at a dose of 3 × 30 mg/day, ranitidine at a dose of 2 × 50 mg/day, and wound care. Histopathology examination revealed a mediastinal schwannoma. For 3 months, the patient-controlled dyspnea, left chest pain, and intermittent cough disappeared once a month.

Discussion

If the tumor is large enough, a thoracoscopic procedure is advised. Because mediastinal schwannomas are benign tumors, most do not get radiotherapy, chemotherapy, and recurrence in this case has not been reported.

Conclusion

Tissue histopathology is used to determine the diagnosis mediastinal schwannoma, whereas radiological evaluation just confirms the diagnosis. The management is thoracotomy for large masses.

Highlights

• •Mediastinal schwannoma is often asymptomatic.
• •Mediastinal schwannoma is a benign tumor that can only be treated surgically.
• •There are no reports of recurrent mediastinal schwannoma.

1. Introduction

Schwannoma is a tumor that develops from the peripheral nerve sheath [1]. Furthermore, schwannoma is an uncommon benign tumor [2,3] with up to 9 % of cases being mediastinal [4]. Histopathological testing provides a clear diagnosis, although other test, including as computer tomography (CT) scan and magnetic resonance imaging (MRI), can also aid in the identification mediastinal schwannoma [5,6]. Based on the surgical case report (SCARE) guideline 2020 [7], the study focused on an Indonesian female with mediastinal schwannoma.

2. Case presentation

An Indonesian female, 61 years old, complained of breathlessness, left chest pain, and intermittent cough 3 months ago. She does not have hypertension, diabetes mellitus, chronic heart disease, hepatitis, asthma, and allergies. She also does not take anti-tuberculosis drugs (ATD) or any other medications. Her physical condition was stable, with a Glasgow coma scale (GCS) of compos metis, blood pressure of 110/70 mmHg, respiratory rate of 24 ×/min, and oxygen saturation of 98 % with the exception of a pulse rate of 110 ×/min. Except for aberrant result in the lung cavity, the physical examination was stable. Physical lung examination revealed no intercostal retraction, enlargement of the collateral veins, broadening of the intercostals, or symmetrical lung development. In the top region of the left hemithorax, palpation fremitus was reduced. Over the upper third of the left hemithorax, percussion was dull. During auscultation, vesicular breath sounds reduced in the top part of left hemithorax.

A cystic lesion in the superior left lung was discovered during a radiological examination, chest X-ray, and thoracic CT scan (Fig. 1). Increased lactate dehydrogenase (LDH) of 242 μ/L, negative anti-hepatitis A virus immunoglobulin M (anti-HAV IgM), negative anti-hepatitis C virus (anti-HCV), and three non-reactive human immunodeficiency virus (HIV) techniques were found in laboratory tests. Spirometry revealed vital capacity (VC) values of 2010 (74 %), forced vital cavity (FVC) of 1800 (64 %), forced expiratory volume in 1 s (FEV1) of 1700 (76 %), FEV1/FVC of 94.4 %, indicating a minor restriction disease without blockage. The fine needle aspiration biopsy (FNAB) CT-guiding results revealed no evidence of malignancy. The core biopsy on the left thoracic mass revealed non-specific chronic inflammation with no evidence of malignancy. A fiber optic bronchoscopy (FOB) inspection of the left lung indicates a slight narrowing of the lower division lumen. The aspiration biopsy revealed no evidence of malignancy and cytological examination of bronchoalveolar lavage (BAL) dextra et sinistra revealed no malignant cells.

Fig. 1.

A. Chest X-ray showed a homogeneous 1/3 opacity over the left hemithorax with regular and well-defined edges.

B-C. A thoracic CT scan revealed a cystic lesion with a solid enhancing component on the apicoposterior segment of the superior lobe of the left lung adhering to the aortic arch with well-defined borders, which could be a benign lesion, as well as lymphadenopathy in the upper, subcarinal, and right lower paratracheal.

The patient underwent surgery, which revealed a cystic, encapsulated left posterior mediastinal tumor with firm boundaries, an impression of origin from the apex of the left thoracic cavity, and no adhesions with surrounding organs. The tumor was excised (Fig. 2). On the fourth day of surgery, the chest tube was removed and receiving therapy included cefixime of 2 × 200 mg/day, ketorolac of 3 × 30 mg/day, ranitidine of 2 × 50 mg/day, and wound care. The anatomic pathology examination revealed that the tumor tissue was partially loose in microcytic and partly densely packed, consisting of proliferating cells with oval-spindle wavy nuclei, fine chromatin, and was rather monotonous. In denser areas, tumor cells are often arranged in palisades. No signs of malignancy were seen (Fig. 3). The prognosis was favorable for patients who received outpatient care once a month for three months and had no severe symptoms.

Fig. 2.

Tissue excision occurred during thoracotomy.

Fig. 3.

Histopathology tissue showed a mediastinal schwannoma.

3. Discussion

Schwannoma, also known as neurilemmoma, is a benign peripheral nerve sheath tumor that is usually always solitary. Schwannomas account for 95 % of all benign neurogenic mediastinal tumors of Schwann cell origin, which most typically affect the mediastinal region but can also be seen in the belly, pelvis, and chest wall [2,8]. Neurogenic tumors account for 12–39 % of all mediastinal tumors, schwannomas accounting for around 95 % [9]. Slow-growing neurogenic tumors of mediastinal peripheral nerves, sympathetic and parasympathetic ganglia, and embryonic remnants of nerve sheaths [10]. These tumors typically develop from spinal nerve roots, however they can also develop from intrathoracic nerves. Furthermore, schwannomas can be discovered in the lungs in about 0.2 % of cases [11].

Clinical symptoms of mediastinal benign schwannoma include coughing and chest discomfort. Other symptoms include weight loss and hoarseness in the meanwhile. Mediastinal tumors can be seen on radiology as well-defined lesions with uncommon calcifications [11]. On a CT scan without contrast, schwannoma appears as smooth, spherical, hypodense lesions in the chest wall muscles. Following contrast delivery, several patterns are observed, including a homogeneous pattern accompanied by multiple hypodense or cystic patches. Bronchoscopy can assist in distinguishing mediastinal tumors from primary lung cancer. Histopathological examination of a schwannoma reveals macroscopic features of a grey-white tumor that linked to nerves, well-defined, encapsulated, solid, and exhibiting cystic degeneration [12]. Meanwhile, microscopic histological examination revealed the proliferation of Schwan cells with spindle nuclei and pointed ends, with 2 growth patterns identified: Antony A (hypercellular, with nuclei foci arranged like palisades called verocacy bodies) and Antony B (hypocellular, loosely arranged) [13].

All benign neurogenic tumors are treated with surgery, except for neuroblastoma [13,14]. The thoracotomy surgical technique is used for resection of large mediastinal tumors, whereas video-assisted thoracoscopy is ideal for smaller tumor masses free from surrounding vital structures. It also reduces morbidity by avoiding costal retraction, muscle cutting, postoperative pain, and can shorten the length of stay when compared to thoracotomy [4]. In case reports of benign neoplasms, full excision of the lesion is usually adequate. All benign neoplasms that are encapsulated must be removed without destroying the capsule [10]. There have been no reports of recurrence in fully resected schwannoma cases to date. Long-term outcomes are generally flawless. None of the patients required additional treatment 20 months following surgery [15].

4. Conclusion

An Indonesian female, 60 years old, complained of breathlessness, left chest pain, and an intermittent cough. A cystic lesion in the left lung was discovered on radiological evaluation and no evidence of malignancy or metastases were found. A histopathology examination revealed a mediastinal schwannoma. Schwannomas are frequently asymptomatic and so are diagnosed accidentally. The radiological examination can assist in making a diagnosis. Histopathological analysis of the tissue establishes the definitive diagnosis. With a big tumor, schwannoma is treated surgically via thoracotomy. Mediastinal schwannomas have a great prognosis; there have been no instances of recurrent schwannomas up to this point.

Sources of funding

N/A.

Ethical approval

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

CRediT authorship contribution statement

Septian Husodo: data curation, supervision, visualization, investigation, drafting; Farah Fatma Wati: conceptualization, methodology, drafting, editing, revising, and reviewing.

Guarantor

Farah Fatma Wati is the person in charge of the publication of our manuscript.

Declaration of competing interest

N/A.