BCL-2 expression and inhibin-A in adrenal neoplasms: a comparative study.

Differential diagnosis between adrenal cortical and adrenal medullary lesions may be difficult in many cases. Different immunohistochemical, histochemical tools as well as ultrastructural diagnostic techniques have been employed to aid in differentiating between these lesions. Recently, both inhibin-A and BCL-2 have been shown to stain selectively adrenal cortical tissue and its derived neoplasms but not adrenal medulla or pheochromocytomas. In this study we compared the staining reactions of inhibin-A and BCL-2 in cases of adrenal cortical adenomas and carcinomas as well as pheochromocytomas. We found that both inhibin-A and BCL-2 stained cortical derived tissues, but not medullary derived tissues. Staining intensity for inhibin-A was significantly weaker than for BCL-2. We found that fixation techniques may influence the staining reactivity, as some cases did not immunoreact with any of the antibodies. We conclude that both inhibin-A, and, preferentially, BCL-2 are useful additions to a staining protocol to help in the differential diagnosis of cortical and medullary neoplasms.