The sAC Antibody Profile as a Diagnostic Adjunct in the Assessment of Pigmented Lesions.
Cynthia M Magro, Garrett Desman, Jonathan Zippin, Neil A Crowson, Paul Chadwick. Weill Cornell Medical College, New York, NY; Laboratory of Dermatopathology, New York, NY; Regional Medical Laboratory, Tulsa, OK
Background: Melanocytic proliferations exhibit striking heterogeneity in regards to their morphology and biologic behavior. Based on prior studies which showed a distinctive pattern in hyperproliferative squamous lesions, we chose to study soluble adenylate cyclase (sAC) antibody expression in a variety of melanocytic lesions.
Design: The immunohistochemical staining procedure for SAC has been previously described. A spectrum of melanocytic lesions was assessed. Among the cases studies were benign nevi, dysplastic nevi and malignant melanoma.
Results: In benign nevi a dot-like perinuclear Golgi staining pattern in the majority of the melanocytes.
In dysplastic nevi a peri nuclear dot-like Golgi pattern analogous to the benign nevus was seen; as well with higher grade atypia a broad golgi pattern of staining was observed. In addition there was was a minor intraepidermal ccomponent with pan-nuclear staining; the number of positive staining cells showing this staining was proportionate to the degree of atypia. In malignant melanoma, extensive and prominent pan nuclear staining was noted in many cases.
A loss of the golgi pattern was seen in several cases. The differential staining patterns aided in distinguishing capsular nevus from metastatic melanoma.
Conclusions: We found that very characteristic patterns emerged with this antibody depending on the nature of the melanocytic lesion biopsied with the hallmark of the malignant phenotype being extensive SAC expression in the nucleus with loss of golgi staining. Nuclear sAC is capable of activating CREB. Metastatic progression of melanoma is associated with overexpression and activity of nuclear CREB resulting in the down-regulation of CCN1/CYR61 expression.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 208, Wednesday Morning