Cell cycle and apoptosis regulators in Spitz nevi: comparison with melanomas and common nevi.
BACKGROUND
Deregulated cell cycle control is one of the hallmarks of tumor development. The expression of different cell cycle regulators has been used in various neoplasms as an adjunct to diagnosis.


OBJECTIVE
We sough to determine the expression of cell cycle and apoptosis regulators in Spitz nevi and to appraise its value as a diagnostic adjunct in the differential diagnosis from melanomas and common nevi.


METHODS
Ki-67, p-27, p-16, p-53, p-21, Rb, cyclin D1, cyclin A, cyclin B1, bcl-2, and bax expression was assessed by immunohistochemistry in 10 Spitz nevi and was compared with 16 melanomas and 20 common nevi immunohistochemical expression.


RESULTS
P-27 (60% +/- 20.13), p-16 (62.00% +/- 10.85), and bcl-2 (46.00% +/- 42.47) were highly expressed in Spitz nevi, whereas Ki-67 (2.80% +/- 2.55), Rb (3.75% +/- 4.55), p-53 (2.30% +/- 0.10), cyclin A (0.70% +/- 1.56), B1 (0.20% +/- 0.34), and bax (2.65% +/- 6.37) demonstrated a limited expression. Cyclin D1 (8.60% +/- 7.30) and p-21 (6.40% +/- 5.37) showed a moderate expression. The expression of bax (P = .001), Ki-67 (P < .0001), Rb (P < .0001), p-16 (P < .0001), cyclin A (P < .0001), and cyclin B1 (P < .0001) was significantly higher in melanomas in comparison with Spitz nevi, whereas p-27 expression was significantly higher in Spitz nevi (P < .0001). A trend for significant difference in favor of melanomas was also observed for p-53 (P = .002). On the other hand, no difference was detected for bcl-2 (P = .275), p-21 (P = .055), or cyclin D1 (P = .077). Spitz nevi demonstrated a trend for a higher expression for p-21 (P = .008) and cyclin D1 (P = .006), whereas they exhibited lower p-16 (P = .004) in comparison with common nevi.


CONCLUSIONS
The number of Spitz nevi was relatively small.


CONCLUSIONS
Spitz nevi differ from melanomas in their immunohistochemical pattern of expression of cell cycle and apoptosis regulators and more closely resemble common benign nevi.
Stefanaki
Christina
C
Dermatology Department, Andreas Sygros University Hospital, Greece. cstefana@otenet.gr
Stefanaki
Kalliopi
K
Antoniou
Christina
C
Argyrakos
Theodoros
T
Patereli
Amalia
A
Stratigos
Alexander
A
Katsambas
Andreas
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000096:biosynthesis*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000503:physiopathology*; D008875:Middle Aged; D009506:Nevus / Q000175:diagnosis / Q000503:physiopathology; D018332:Nevus, Epithelioid and Spindle Cell / Q000175:diagnosis / Q000503:physiopathology*; D012878:Skin Neoplasms / Q000175:diagnosis / Q000503:physiopathology*
D018797:Cell Cycle Proteins