Pulmonary gangliocytic paraganglioma: case report and comparative immunohistochemical study of related neuroendocrine neoplasms.

The authors report a case of gangliocytic paraganglioma of the lung, which has not yet been described in a pulmonary neoplasm. A 75-year-old man underwent right middle and lower lobe lobectomy. A slightly yellowish mass was located at the bifurcation between the lower and middle lobe bronchus, protruding into the truncus intermedius. The neoplastic cells were composed of three cellular elements: uniform endocrine cells in a Zellballen arrangement, large ganglion-like cells within the nests of endocrine cells, and spindle-shaped cells arranged in streams to surround the nests. Each component exhibited the characteristic immunohistochemical properties, which were similar to those of the corresponding neuroendocrine neoplasms: Endocrine cells were positive for CAM 5.2, chromogranin A, and synaptophysin, like carcinoid tumor; ganglion-like cells were positive only for neurofilament, like ganglioneuroma; and spindle-shaped cells were positive for neurofilament and S-100 protein, like paraganglioma. These results agreed with those in gangliocytic paraganglioma of the duodenum. Pulmonary gangliocytic paraganglioma is similar to that in the duodenum, and is a hamartomatous proliferation of epithelial endocrine and neuronal cells of the bronchus.