Abstract
Desmoplastic melanoma (DM) is a variant of melanoma, which typically affects chronically sun-damaged skin of elderly patients. Pure DM displays a low density of fusiform melanocytes in a collagen-rich matrix. In mixed DM, tumor cell density is higher, and parts of the tumor lack abundant stromal fibrosis. Both pure and mixed DMs usually express S100 protein homogenously. We report herein an unusual biphenotypic tumor characterized by the association of a pure DM with an undifferentiated solid spindle cell nodule. It occurred on the scalp of a 66-year-old man. A biopsy of the undifferentiated spindle cell nodule was initially interpreted at a commercial laboratory as atypical fibroxanthoma. The pure DM was seen only in the excisional specimen. All cells of the pure DM stained for S100 protein and SOX10. The adjacent solid sarcomatoid spindle cell nodule lacked expression of S100 protein, SOX10, as well as melan-A, gp100, and microphthalmia-associated transcription factor in >95% of its tumor cells. Although focal expression of melanocyte differentiation antigens in the solid tumor component made us favor a combined DM with sarcomatoid dedifferentiation, we also considered the possibility of a collision scenario, that is, a pleomorphic dermal sarcoma incidentally colliding with a DM. To further assess a possible relationship of the sarcomatoid nodule with the DM, we performed next-generation sequencing analysis on each component separately. The analysis revealed shared chromosomal copy number changes and a high number of common mutations, thereby supporting the concept of a DM with a dedifferentiated sarcomatoid component. An interesting finding is the presence of mutations of the neurofibromin 1 (NF1) gene in both tumor components.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 864-870 |
| Number of pages | 7 |
| Journal | American Journal of Surgical Pathology |
| Volume | 38 |
| Issue number | 6 |
| DOIs | |
| State | Published - 2014 |
| Externally published | Yes |
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Keywords
- Biphenotypic tumor
- Desmoplastic melanoma
- Next-generation sequencing
- Sarcoma
ASJC Scopus subject areas
- Anatomy
- Pathology and Forensic Medicine
- Surgery
Cite this
Desmoplastic melanoma with sarcomatoid dedifferentiation. / Kiuru, Maija Ht; Mcdermott, Gregory; Berger, Michael; Halpern, Allan C.; Busam, Klaus J.
In: American Journal of Surgical Pathology, Vol. 38, No. 6, 2014, p. 864-870.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Desmoplastic melanoma with sarcomatoid dedifferentiation
AU - Kiuru, Maija Ht
AU - Mcdermott, Gregory
AU - Berger, Michael
AU - Halpern, Allan C.
AU - Busam, Klaus J.
PY - 2014
Y1 - 2014
N2 - Desmoplastic melanoma (DM) is a variant of melanoma, which typically affects chronically sun-damaged skin of elderly patients. Pure DM displays a low density of fusiform melanocytes in a collagen-rich matrix. In mixed DM, tumor cell density is higher, and parts of the tumor lack abundant stromal fibrosis. Both pure and mixed DMs usually express S100 protein homogenously. We report herein an unusual biphenotypic tumor characterized by the association of a pure DM with an undifferentiated solid spindle cell nodule. It occurred on the scalp of a 66-year-old man. A biopsy of the undifferentiated spindle cell nodule was initially interpreted at a commercial laboratory as atypical fibroxanthoma. The pure DM was seen only in the excisional specimen. All cells of the pure DM stained for S100 protein and SOX10. The adjacent solid sarcomatoid spindle cell nodule lacked expression of S100 protein, SOX10, as well as melan-A, gp100, and microphthalmia-associated transcription factor in >95% of its tumor cells. Although focal expression of melanocyte differentiation antigens in the solid tumor component made us favor a combined DM with sarcomatoid dedifferentiation, we also considered the possibility of a collision scenario, that is, a pleomorphic dermal sarcoma incidentally colliding with a DM. To further assess a possible relationship of the sarcomatoid nodule with the DM, we performed next-generation sequencing analysis on each component separately. The analysis revealed shared chromosomal copy number changes and a high number of common mutations, thereby supporting the concept of a DM with a dedifferentiated sarcomatoid component. An interesting finding is the presence of mutations of the neurofibromin 1 (NF1) gene in both tumor components.
AB - Desmoplastic melanoma (DM) is a variant of melanoma, which typically affects chronically sun-damaged skin of elderly patients. Pure DM displays a low density of fusiform melanocytes in a collagen-rich matrix. In mixed DM, tumor cell density is higher, and parts of the tumor lack abundant stromal fibrosis. Both pure and mixed DMs usually express S100 protein homogenously. We report herein an unusual biphenotypic tumor characterized by the association of a pure DM with an undifferentiated solid spindle cell nodule. It occurred on the scalp of a 66-year-old man. A biopsy of the undifferentiated spindle cell nodule was initially interpreted at a commercial laboratory as atypical fibroxanthoma. The pure DM was seen only in the excisional specimen. All cells of the pure DM stained for S100 protein and SOX10. The adjacent solid sarcomatoid spindle cell nodule lacked expression of S100 protein, SOX10, as well as melan-A, gp100, and microphthalmia-associated transcription factor in >95% of its tumor cells. Although focal expression of melanocyte differentiation antigens in the solid tumor component made us favor a combined DM with sarcomatoid dedifferentiation, we also considered the possibility of a collision scenario, that is, a pleomorphic dermal sarcoma incidentally colliding with a DM. To further assess a possible relationship of the sarcomatoid nodule with the DM, we performed next-generation sequencing analysis on each component separately. The analysis revealed shared chromosomal copy number changes and a high number of common mutations, thereby supporting the concept of a DM with a dedifferentiated sarcomatoid component. An interesting finding is the presence of mutations of the neurofibromin 1 (NF1) gene in both tumor components.
KW - Biphenotypic tumor
KW - Desmoplastic melanoma
KW - Next-generation sequencing
KW - Sarcoma
UR - http://www.scopus.com/inward/record.url?scp=84900840963&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84900840963&partnerID=8YFLogxK
U2 - 10.1097/PAS.0000000000000201
DO - 10.1097/PAS.0000000000000201
M3 - Article
C2 - 24618614
AN - SCOPUS:84900840963
VL - 38
SP - 864
EP - 870
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
SN - 0147-5185
IS - 6
ER -