TY  - JOUR
A1  - Glutsch, Valerie
A1  - Wobser, Marion
A1  - Schilling, Bastian
A1  - Gesierich, Anja
A1  - Goebeler, Matthias
A1  - Kneitz, Hermann
T1  - PRAME expression as helpful immunohistochemical marker in rhabdoid melanoma
JF  - Dermatopathology
N2  - Background: Rhabdoid melanoma is a rare variant of malignant melanoma with characteristic cytomorphologic features. Due to the potential loss of conventional melanocytic markers, histopathologic diagnosis is often challenging. We hypothesize that immunostaining for PReferentially expressed Antigen in MElanoma (PRAME) might have the potential to uncover the melanocytic origin of these dedifferentiated tumors. Methods: Four cases of rhabdoid primary melanomas were assessed by immunohistochemistry for expression of PRAME and conventional melanocytic markers. Immunohistochemical expression patterns were analyzed in the rhabdoid primaries and, if available, associated metastases. Results: All four cases of rhabdoid primary melanomas showed a strong nuclear positivity for PRAME, while the expression of conventional melanocytic markers S100, MART-1, SOX-10 and HMB-45 was variable between the analyzed cases. Conclusions: In summary, we report four cases of rhabdoid primary melanoma with high to intermediate expression of PRAME despite the partial and variable loss of other melanocytic markers. Hence, PRAME might facilitate the recognition of this highly aggressive entity to avoid misdiagnosis due to histopathologic pitfalls.
KW  - PRAME
KW  - rhabdoid differentiation
KW  - rhabdoid melanoma
KW  - immunohistochemistry
KW  - melanocytic markers
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284115
SN  - 2296-3529
VL  - 9
IS  - 2
SP  - 148
EP  - 157
ER  - 
TY  - JOUR
A1  - Frings, Verena Gerlinde
A1  - Goebeler, Matthias
A1  - Schilling, Bastian
A1  - Kneitz, Hermann
T1  - Aberrant cytoplasmic connexin43 expression as a helpful marker in vascular neoplasms
JF  - Journal of Cutaneous Pathology
N2  - Background
Gap junctions consisting of connexins (Cx) are fundamental in controlling cell proliferation, differentiation, and cell death. Cx43 is the most broadly expressed Cx in humans and is attributed an important role in skin tumor development. Its role in cutaneous vascular neoplasms is yet unknown.

Methods
Fifteen cases each of cutaneous angiosarcoma (cAS), Kaposi sarcoma (KS), and cherry hemangioma (CH) were assessed by immunohistochemistry for expression of Cx43. Expression pattern, intensity, and percentage of positively stained cells were analyzed. Solid basal cell carcinomas served as positive and healthy skin as negative controls.

Results
Most cases of cAS presented with a strong Cx43 staining of almost all tumor cells, whereas endothelia of KS showed medium expression and CH showed mostly weak expression. In comparison with KS or cAS, the staining intensity of CH was significantly lower (P ≤ 0.001). All tissue sections of both cAS and KS were characterized by a mostly diffuse, cytoplasmic staining pattern of the vascular endothelia. None of those showed nuclear staining.

Conclusion
The high-to-intermediate expression of Cx43 observed in all cases of cAS and KS suggests that this Cx may play a role in the development of malignant vascular neoplasms and serve as a helpful diagnostic marker.
KW  - Kaposi sarcoma
KW  - cutaneous angiosarcoma
KW  - Cx43
KW  - hemangioma
KW  - immunohistochemistry
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258412
VL  - 48
IS  - 11
ER  -