On the Origin and Diagnostic Criteria of Olfactory Neuroblastoma

抄録

The origin and diagnostic criteria of olfactory neuroblastoma are still under dispute. Tosolve these problems, seven cases of olfactory neuroblastomas satisfying diagnostic criteria of Choi and Anderson were analyzed immunohistochemically by using antibodies to markers expressed in developing and mature human olfactory placode-derived neurons such as keratin, a 34 kDa epithelial membrane glycoprotein, luteinizing-hormone-releasing-hormone (LHRH) and to other neural tissue markers. Ultrastructural analysis was also carried out. Five cases were identified as neuroblastomas because neurites were disclosed in them. All of these five cases had widespread immunoreactivity to an antibody to a 34 kDa epithelial membrane glycoprotein (Ber-EP4) in the tumor cell bodies and/or neuritic processes. They also contained keratin positive cells. LHRH was demonstrated in two of these Ber-EP4 positive neuroblastomas. The spectrum of immunohistochemical findings of these five cases was identical to the normal neuroblasts arising from olfactory placode.
Accordingly, it is concluded that neuroblastoma of true olfactory placodal origin does exist. The diagnostic criteria of this tumor is as follows: demonstration of neurites and immunoreactivity to Ber-EP4 and/or LHRH. Keratin is not necessary to regard as an evidence of epithelial differentiation in this tumor.