Oversized primary intrapulmonary schwannoma: A case report and a review of the literature

Abstract

Background: Schwannomas, also known as neurilemommas, are benign, well-circumscribed encapsulated peripheral nerve sheath tumors with rather indolent evolution. Made up of cells closely related to normal myelinating Schwann cells, these neoplasms may arise from the peripheral nervous system as well as from spinal or cranial nerves. They are mostly found in the base of the skull, neck, chest wall, posterior mediastinum, posterior spinal roots, cerebellopontine angle, retroperitoneum, and flexor surfaces of the extremities. The incidence rate of spinal schwannoma is 0.3–0.5/100,000 cases per year with an average age of 50 at diagnosis. We report a case of intrapulmonary schwannoma, adding a review of the literature. Case Description: A 20-year-old female patient with no significant medical history, presented with pleuritic chest pain, shortness of breath, right upper limb weakness, and numbness. A computed tomography of the chest and magnetic resonance imaging showed a 7.2 × 10.5 × 8.3 cm mass in the posterior segment of the right upper lobe, arising from the right T5-6 neural foramen; a concurrent 16 mm thick right pleural effusion was also noticed yet without evidence of nodular enhancement. The findings suggested the presence of a neurofibroma or a schwannoma. Complete resection of the tumor was achieved through posterolateral thoracotomy; the ensuing histopathological and immunohistochemical examinations confirmed the presence of a schwannoma. Conclusion: We believe this rare case of pulmonary invasive schwannoma illustrates the complex dynamics of this extremely rare entity; in this particular case, complete surgical excision proved to be crucial in terms of subacute management and local tumor control, at least at short and middle term. The patient is currently asymptomatic (6 months postsurgery) and remains on follow-up.

Difficulty Breathing or Just a Case of the Nerves? Incidental Finding of Primary Pleural Schwannoma in a COVID-19 Survivor

“…The most classical marker for schwannomas remains the S-100 stain, which is usually strong and diffuse, helping to clarify ambiguities in diagnosis. Other histological features seen very commonly are nuclear palisading with elongated and wavy contours and Antoni A and B areas (alternating hyper and hypocellular areas respectively) [ 2 , 3 ].…”

“…Conservative observation has little to no justification, as primary surgical removal serves a manifold purpose, providing definitive diagnosis as well as therapy. Depending on the characteristics of the tumor, a surgical approach could involve either a minimally invasive procedure or an open thoracotomy; the precise indications of either of which are beyond the scope of this paper [ 2 ].…”

“…They are usually well-circumscribed, encapsulated, and almost always solitary [ 1 ]. Furthermore, these tumors histopathologically reflect their origin, being closely related to the normal Schwann cells [ 2 ].…”

“…As anatomic logic would dictate, these masses commonly occur in the skull base, cerebellopontine angle, and posterior spinal roots [ 1 ]. However, literature does report other locations such as the neck, chest wall, and cavity; with up to 75% arising from the posterior mediastinum, usually in association with paraspinal nerves and soft-tissue sites [ 2 , 3 ].…”

Large mediastinal schwannoma with great vessel encroachment requiring vascular reconstruction: a case report

“…Management of mediastinal schwannomas is guided by several factors, which includes clinical presentation and symptoms, tumor size, location, complications due to tumor growth, and pathology ( 8 ). Schwannomas tend to grow slowly and can have a long indolent course, therefore small, asymptomatic, incidentally found mediastinal schwannomas can be observed with serial imaging to monitor progression ( 9 ). However, given the propensity for the mediastinal tumor to continue to grow and potentially invade surrounding structures, the treatment of choice is surgical resection of the mass, either by video assisted thoracoscopy or thoracotomy, for definitive diagnosis and treatment ( 3 , 6 , 10 ).…”