MALIGNANT NEURILEMMOMA OF THE LUNG METASTASIZING TO THE HEART

Intrapulmonary cellular schwannoma

A 75-year-old asymptomatic woman was admitted to our hospital after an abnormal shadow was found on a chest roentgenogram. Chest computed tomography showed a round mass in the right lower lobe. Magnetic resonance imaging showed the mass with high signal intensity on T2-weighted images and intermediate signal intensity on T1-weighted images. Fluorine-18-fluorodeoxyglucose-positron emission tomography showed high fluorine-18-fluorodeoxyglucose accumulation in the mass. A lobectomy was performed thoracoscopically. The pathologic diagnosis was cellular schwannoma. Immunohistochemical staining demonstrated the presence of S-100 protein, and the Ki67 labeling index was 12%. We present this case of intrapulmonary cellular schwannoma, which is extremely rare.

A case of primary intrapulmonary neurilemoma and review of the literature

In this paper, we present an extremely rare case of a primary intrapulmonary neurogenic tumor, in which localization of S-100 protein, neuron specific gamma-enolase (NSE) and CEA was investigated using immunohistochemical staining. The patient, who was a 39-year-old man, experienced no symptoms; however, a routine chest X-ray revealed a round tumor-like shadow in the infrahilar area of the right lung. As the tumor appeared to be gradually increasing in size, surgery was performed and histopathological examination of the excised tumor revealed it to be a primary intrapulmonary neurilemoma. Immunohistochemical staining demonstrated the presence of S-100 protein in the tumor cells but NSE and CEA were not detected. For the 2 years following his operation, the patient has been in good health and is now under careful observation.

Malignant neurilemmoma of left atrium

A 31-year-old woman, whose chief complaint was back pain, was found to have an echocardiographic abnormality suggestive of a left atrial myxoma. Angiography clearly showed a large radiolucent mass protruding from the left atrium into the left ventricle during diastole. X-rays of the sacrum disclosed the presence of a malignant tumour. Biopsy specimens taken from the tumour in the sacral plexus showed a malignant neurilemmoma. Despite extensive chemotherapy, widespread metastases developed and the patient died four months after admission. Necropsy disclosed three discrete tumours in the left atrium, which were found to be malignant neurilemmoma, shown on histology to be metastases from the primary in the sacral plexus.