Transcript Morphologic appearance of regression in thin cutaneous

Morphologic appearance of regression in thin cutaneous melanomas
Sabina Zurac1, R. Andrei1, T. Tebeica1, Roxana Mustata2, Gabriela Negroiu3, Stefana Petrescu3,
Virginia Chitu4, Rozalia Olsavszky4, A. Rebosapca5, B. Andreescu5, I. Marinescu5, Florica Staniceanu1
1.Dept. of Pathology, 4.Dept. of Dermatology, 5.Dept. of Plastic Surgery Colentina University Hospital,
2.Terramed Conformal Clinic, 3.Institute of Biochemistry of Romanian Academy, Bucharest, Romania
Background: Regression in melanoma is a relatively common phenomenon, occurring in 10-35% of
cases, depending on stage (up to 60% of melanoma thinner than 0.75 mm). However, despite
accumulated data indicating both tumor regression achievement by immune cell action on tumor cells
and crucial significance of the immune response in malignancies of other organs, the biologic significance
of regression in melanomas is still on debate.
Material and method: We analyzed 46 thin superficial spreading melanomas (Breslow index < 1mm):
-25 presented regression (14 with segmental regression - SR, 11 with partial regression PR)
-21 cases had no regression (NR).
Results:
PR melanoma
predominates in
30-49 yrs patients
 SR melanoma
mainly in 50-69 yrs
patients
(P=0.0198).
variation of regression according
the age of the patients
100%
80%
60%
absen
t
partial
40%
20%
segm
ental
0%
< 3030-3940-4950-5960-69 > 70
Slight
tendency
towards
spindle cell
phenotype
in NR
melanomas.
100%
cellular phenotype
epitheliod&
spindle
80%
60%
40%
epithelioid,
rare spindle
20%
epithelioid
0%
SR PR NR
Regression absent in melanomas
with high mitotic index (P=0.029)
with tendency towards fewer
mitoses in SR than PR and/or NR
melanomas.
SR melanomas tend
to have larger
regression areas with
lesser fibroplasia than
PR cases.
variation of regression according
to mitotic index (MI)
100%
grade of fibrosis in regressed areas
according to regression type
MI
>2
80%
60%
Partial regression in melanoma with
Breslow 0.22.
100%
80%
MI
1-2
40%
20%
0%
SR
PR
NR
+++
++
+
60%
40%
variation of regression according to Breslow
index
MI
<1
20%
0%
SR
PR
100%
80%
NR
60%
PR
40%
SR
20%
0%
< 0.45
Partial regression in melanoma
without noticeable mitoses.
0.45-0.75
> 0.75
Very thin melanomas
(Breslow <0.45 mm)
tends to associate PR.
Partial regression with moderate
fibrosis in the regressed area.
Tumor infiltrating lymphocytes
(TIL) are almost significantly more
numerous in SR melanomas than
NR ones (P=0.06), while PR and
NR melanomas have similar TIL
distribution.
The more extended, the
thicker were the areas of
regression in SR melanomas.
Correlation between thickeness and
extension of regressed areas in
segmental regression
variation of regression according to TIL
presence
7
6
Plasma cells in segmental regression
5
100%
<
0.75
0.761
4
3
80%
2
variation of regression according
to plasma cells presence
1
TIL +++
60%
TIL +
40%
0
0-25
25-50
50-75
75-100
20%
100%
80%
0%
NR
PR
SR
60%
Correlation between thickeness and
extension of regressed areas in partial
regression
40%
8
20%
7
0%
TIL -
SR
PR
NR
plasma cells - plasma cells +
6
5
< 0.75
4
0.76-1
3
>1
2
1
0
0-25
25-50
50-75
75-100
SR melanomas associate
presence of plasma cells
within tumor inflammatory
infiltrate (P=0.0173), while PR
melanomas do not (P=0.21).
Relatively frequent TILs in melanoma
with segmental regression in other areas
Conclusions:
In thin melanomas, partial
and segmental regression
seem to belong to different
spectrum of alteration.
SR
melanomas
present
features usually associated
with better prognosis (older
age, low mitotic index, TIL
presence)
Extended area of segmental regression
There are significantly more
numerous plasma cells within
SR areas, suggesting an
antibodies-mediated
immunological
mechanism
rather than a cellular one as
previously expected.
Acknowledgments: project partially supported by Postdoctoral Program POSDRU/89/1.5/S/60746