Pulmonary Paraganglioma: A case report.

Abstract

Extra-adrenal paragangliomas are uncommon tumors arising from neuroectodermal-derived paraganglion tissue. These tumors are usually located in the carotid body, the jugulotympanic body or the mediastinum. A limited number of primary pulmonary paragangliomas have been reported previously. We present a case of a 63-year-old lady with a 12-pack-year smoking history and shortness of breath. Radiological investigations revealed a single right middle lobe pulmonary mass with homogenous density and lobulated borders on CT scan. The mass showed high fluorodeoxyglucose avidity on PET scan. A right middle lobectomy of the lung was performed. Macroscopic examination showed a well-defined yellow to cream mass measuring 28 mm in maximum dimension. Histologically, the mass was composed of alveolar pattern of spindle cells with granular cytoplasm. No lymph node metastasis was identified. Immunohistochemical stains performed showed that the tumour is positive for chromogranin, synaptophysin, TTF-1, but negative for CK7. S-100 stained the sustentacular cells in the tumour. While approximately 20% of carcinoid tumours are reported to be negative for keratins, the overall histological and radiological features are those of a paraganglioma. The case report describes the radiological and histopathological characteristics of this exceedingly rare tumour, thereby improving its understanding and helping in the differential diagnosis of pulmonary tumours.