Pulmonary paraganglioid carcinoids and bcl-2 oncoprotein expression

Bcl-2 protein immunoreactivity was examined in 10 pulmonary carcinoid tumors with abundant S-100 protein-positive sustentacular cells (SCs) diagnosed as paraganglioid carcinoids. Its positivity in the mentioned tumors was compared with that of neoplasms formed of neuroendocrine cells only (30 pulmonary carcinoids), and with another group of 30 lesions consisting of neuroendocrine and sustentacular elements, i.e., paragangliomas (11 paragangliomas of the glomus caroticum and 9 jugulotympanic paragangliomas [JPTGs]), pheochromocytomas (5 cases), and a rare form of pulmonary tumorlets (PTUs) with a high frequency of SCs (5 cases).