Cellular schwannoma of the bronchus.

A cellular schwannoma in a bronchus of a 64-year-old female is reported with immunocytochemical and ultrastructural observations. One previous case arising in the lung has been reported. The tumor formed a 3-cm exophytic mass in a segmental bronchus. Pneumonectomy was performed. The tumor was moderately cellular and devoid of Verocay bodies, and the spindle cells were immunoreactive for S-100 protein. Electron microscopy revealed schwannian features that were less developed than in a classic schwannoma.