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  - Wobser, Marion
A1  - Schummer, Patrick
A1  - Appenzeller, Silke
A1  - Kneitz, Hermann
A1  - Roth, Sabine
A1  - Goebeler, Matthias
A1  - Geissinger, Eva
A1  - Rosenwald, Andreas
A1  - Maurus, Katja
T1  - Panel sequencing of primary cutaneous B-cell lymphoma
JF  - Cancers
N2  - Background: Primary cutaneous follicular B-cell lymphoma (PCFBCL) represents an indolent subtype of Non-Hodgkin’s lymphomas, being clinically characterized by slowly growing tumors of the skin and common cutaneous relapses, while only exhibiting a low propensity for systemic dissemination or fatal outcome. Up to now, only few studies have investigated underlying molecular alterations of PCFBCL with respect to somatic mutations. Objectives: Our aim was to gain deeper insight into the pathogenesis of PCFBCL and to delineate discriminatory molecular features of this lymphoma subtype. Methods: We performed hybridization-based panel sequencing of 40 lymphoma-associated genes of 10 cases of well-characterized PCFBCL. In addition, we included two further ambiguous cases of atypical B-cell-rich lymphoid infiltrate/B-cell lymphoma of the skin for which definite subtype attribution had not been possible by routine investigations. Results: In 10 out of 12 analyzed cases, we identified genetic alterations within 15 of the selected 40 target genes. The most frequently detected alterations in PCFBCL affected the TNFRSF14, CREBBP, STAT6 and TP53 genes. Our analysis unrevealed novel mutations of the BCL2 gene in PCFBCL. All patients exhibited an indolent clinical course. Both the included arbitrary cases of atypical B-cell-rich cutaneous infiltrates showed somatic mutations within the FAS gene. As these mutations have previously been designated as subtype-specific recurrent alterations in primary cutaneous marginal zone lymphoma (PCMZL), we finally favored the diagnosis of PCMZL in these two cases based on these molecular findings. Conclusions: To conclude, our molecular data support that PCFBCL shows distinct somatic mutations which may aid to differentiate PCFBCL from pseudo-lymphoma as well as from other indolent and aggressive cutaneous B-cell lymphomas. While the detected genetic alterations of PCFBCL did not turn out to harbor any prognostic value in our cohort, our molecular data may add adjunctive discriminatory features for diagnostic purposes on a molecular level.
KW  - B-cell lymphoma
KW  - primary cutaneous follicular B-cell lymphoma
KW  - targeted sequencing
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290330
SN  - 2072-6694
VL  - 14
IS  - 21
ER  -