A103 immunostaining in the diagnosis of adrenal cortical tumors: an immunohistochemical study of 316 cases.
BACKGROUND
The monoclonal antibody A103 recognizes an antigen on melanoma cells known as Melan-A or MART-1. Recent studies have shown that A103 also reacts with adrenal cortical cells and may be useful in the diagnosis of adrenal cortical tumors. However, only small numbers of some of the tumors in the differential diagnosis of adrenal cortical neoplasms have been studied.


OBJECTIVE
To study the specificity of A103 immunohistochemistry in a large number of tumors in the differential diagnosis of adrenal cortical neoplasms.


METHODS
Formalin-fixed, paraffin-embedded tissue from 21 adrenal cortical tumors, 16 cases of metastatic carcinoma to the adrenal, 10 pheochromocytomas, and 269 extra-adrenal carcinomas was evaluated for A103 immunoreactivity using a commercially available antibody (Novocastra, Newcastle, UK).


RESULTS
Positive staining was seen in all of the adrenal cortical tumors but in none of the adrenal metastases or pheochromocytomas. In the 269 extra-adrenal carcinomas, A103 immunoreactivity was limited to a single ovarian serous carcinoma.


CONCLUSIONS
A103 immunostaining is useful in distinguishing adrenal cortical neoplasms from other carcinomas and pheochromocytoma.
Loy
Timothy S
TS
Department of Pathology, University of Missouri Health Sciences Center, 1 Hospital Drive, Columbia, MO 65212, USA. loyts@health.missouri.edu
Phillips
Roy W
RW
Linder
Chadwick L
CL
D000306:Adrenal Cortex Neoplasms / Q000175:diagnosis*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000951:Antigens, Neoplasm; D006801:Humans; D007150:Immunohistochemistry; D058965:MART-1 Antigen; D009363:Neoplasm Proteins / Q000032:analysis*; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins