IGFII and MIB1 immunohistochemistry is helpful for the differentiation of benign from malignant adrenocortical tumours.
OBJECTIVE
The differentiation of adrenocortical carcinomas from adenomas may be difficult based on morphology alone. Differential expression of insulin-like growth factor (IGF) II and cyclin-dependent kinase (CDK) 4 has recently been described in these tumours. The aim of this study was to investigate the diagnostic usefulness of these markers immunohistochemically.


RESULTS
We examined 22 benign and 17 malignant adrenocortical tumours and compared IGFII and CDK4 expression with known immunohistochemical as well as morphological criteria of malignancy. Thirteen of 17 carcinomas showed immunohistochemical reactivity for IGFII, whereas all adenomas but one were negative. Intense CDK4 expression was detected in 11 of 17 carcinomas but was present in only three of 22 adenomas. The MIB1 index was >5% in 14 of 16 carcinomas and was <5% in all adenomas but one. The combination of IGFII immunohistochemistry with MIB1 index led to high sensitivity and specificity in detecting adrenocortical carcinomas.


CONCLUSIONS
IGFII and MIB1 are helpful immunohistochemical markers to predict malignancy in adrenocortical neoplasms. These markers can be used in addition to clinical, gross and morphological features to establish a diagnosis in difficult cases.
Schmitt
A
A
Institute for Surgical Pathology, Department of Pathology, University Hospital Zurich, Switzerland. anja.schmitt@usz.ch
Saremaslani
P
P
Schmid
S
S
Rousson
V
V
Montani
M
M
Schmid
D M
DM
Heitz
Ph U
PU
Komminoth
P
P
Perren
A
A
D000306:Adrenal Cortex Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D018246:Adrenocortical Adenoma / Q000175:diagnosis* / Q000378:metabolism; D018268:Adrenocortical Carcinoma / Q000175:diagnosis* / Q000378:metabolism; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D051358:Cyclin-Dependent Kinase 4 / Q000096:biosynthesis; D003937:Diagnosis, Differential; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis*; D019394:Ki-67 Antigen / Q000096:biosynthesis*; D008875:Middle Aged; D012680:Sensitivity and Specificity; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis
D014408:Biomarkers, Tumor; D018971:Insulin-Like Growth Factor Binding Protein 2; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53; D051358:Cyclin-Dependent Kinase 4