Primary pulmonary tumours of neurogenic origin.

Abstract

Primary intrapulmonary neurogenic tumors are extremely rare. In a series of 1664 patients with pulmonary neoplasms observed during 1967-1980, only 4 such tumors were identified (0.2%). All 4 patients underwent surgical excision. Histologic diagnosis was benign neurilemmoma in 3 cases and malignant schwannoma in the 4th. The patients with neurilemmoma are alive and well 4-12 yr after surgery but the patient with malignant schwannoma died from metastatic spread of the tumor 4 mo. after surgery. No association with von Recklinghausen''s disease was observed. Macroscopic and microscopic features generally lead to a correct diagnosis in benign types, but histologic diagnosis of malignant schwannoma may present some difficulties and requires the establishment of a definite origin in a nervous structure, identification of benign neurofibroma in different areas of the same tumor and a high density of cells with appreciable pleomorphism, mitosis and atypia. Benign tumors carry a good prognosis with little tendency to recur but malignant schwannoma has a high invasive tendency and is associated with a low survival rate.