Unusual Intrapulmonary Tumor: Diagnosis
Diagnosis: Benign intrapulmonary teratoma and ipsilateral cystic bronchiectasis
Intrathoracic teratomas almost always occur in the mediastinum, and only very rarely arise within the lung. By 1978, Holt et all found 13 histologically confirmed lung teratomata in the world literature. Since then, three have been added to the English, and one to the German literature. Seven tumors have been located in the left upper lobe, three in the right upper lobe, and six confined to the middle and lower lobes; in one, the exact intrapulmonary site was not listed. Eleven tumors have been malignant and six benign. In our patient, the tumor was benign and situated in the right upper lobe. Though extension into the mediastinum was demonstrated, histologic evidence of a primarily intrapulmonary location was convincing. Sections showed pancreatic tissue in direct continuity with bronchioles and cavities; further evidence of this included the presence of a tuft of hair protruding from the upper lobe bronchus on the resected specimen. Reported symptoms associated with pulmonary teratoma have been prolonged and have included cough, hemoptysis, chest pain and trichoptysis. Plain roentgenographs features are of a calcified mass, which may show peripheral translucent areas. In our patient, though calcification was seen, even in retrospect the mass was not discernible on the chest radiographs due to destruction of the contiguous lung. CT appearances were more helpful, indicating a mass of complex structure containing punctate calcification and areas of high local fat content. CT also demonstrated the degree of mediastinal invasion and relationship of the tumor to vascular structures.
One previous report has described bronchiectasis in association with intrapulmonary teratoma. The authors postulated that long term drainage of infected material produced by local tumor compression was the cause.
Because of the prominence of pancreatic glandular tissue in our patients tumor, we suggest that bronchiectasis resulted from digestive enzyme activity on the draining bronchial tree. This hypothesis is supported by the absence of other causes for such extensive bronchiectatic change. Results of repeated cultures for acid-fast bacilli, and tuberculin skin tests were documented to be negative during the six years the patient attended this hospital. Though positive sltin tests to Histoplasma capsulatum were demonstrated, the patient had previously had a full course of therapy with amphotericin B, and bronchiectasis progressed despite repeated negative Histoplasma cultures and stains. The distribution of bronchiectasis was compatible with such a mechanism, showing massive right lung involvement with sparing of the left lung, apart from the lingula.
In retrospect, the tumor was not convincingly appreciable on the plain chest radiograph. The lesion was clearly visible on CT and, had the entity been considered, a diagnosis was possible from percutaneous biopsy histology results.
Pulmonary teratoma is a rare tumor, and we report a case where associated bronchiectasis was a very prominent feature. A relationship between the two conditions in this patient is postulated and the literature reviewed. Awareness of the tumor in the lung and its possible autodigestive properties would have altered management and possibly prevented further bronchial destruction. If the mass contains cartilage and a high fat content, the CT appearances can be expected to be characteristic. We will consider the entity if a similar clinico-radiologic situation is again seen.
