Intercostal schwannoma simulating pulmonary neoplasia

L.A. Henn, R.V. Gonzaga, J. Crestani, M.R. Cerski

Describe the case of a man, tabagist, with a nodule in right lung that showed malignant characteristics detected by routine chest radiographs, whose histopathological diagnosis was benign intercostal schwannoma. The authors reviewed the clinical features, chest radiographs and computer tomographies of the case, and the histological and immunohistochemical aspects of the surgical specimen. The patient was submitted to diagnostic right thoracotomy with resection of the tumor. The conventional histopathological exam showed spindle shaped cells in a--palisading fashion, forming the Verocay's bodies, characteristics of schwannomas. The immunohistochemical was positive to S-100 protein, vimentin and enolases, and negative to neurofilament proteins. The definitive diagnosis of schwannoma is possible only after histopathological and immunohistochemical examination of the tumor. Its cellularity associated with mitotic count and pleomorphism may lead to a mistaken diagnosis of malignant neoplasm. The immunohistochemistry by S-100 protein can characterize the benignity of the lesion, so that this protein is not found in the malignant cells. The intercostal schwannomas of the thoracic wall can mimic pulmonary neoplasm in chest radiographs and computer tomographies.