Intrapulmonary Schwannoma: A Rare Case Report and Review of the Literature

Schwannoma is a benign, well-circumscribed, and encapsulated peripheral nerve sheath tumor that develops from Schwann cells. The growth pattern is usually slow, tending to clinical indolence. Primary pulmonary neuronal tumors are very rare, accounting for ~0.2% of all lung neoplasms, and are often misdiagnosed due to their nonspecific radiological features. A 50-year-old man presented with a large cystic mass in upper lobe of left lung discovered incidentally on chest X-ray during work up after a blunt chest trauma. Gross examination of the mass following surgical excision revealed a well-circumscribed, encapsulated creamy-gray cystic lesion with gelatinous material measuring 10.5 × 6 × 5.5 cm, attached to a segment of lung. Microscopically, the tumor showed hypo- and hypercellular areas with proliferation of elongated wavy cells in a myxoid background which is characteristic of Schwannoma. Despite intrapulmonary schwannomas' rarity, it is essential to consider schwannomas in the differential diagnosis of pulmonary masses, particularly when clinical and radiological findings suggest a well-defined, encapsulated lesion.