Desmoplastic melanoma: an updated immunohistochemical analysis of 40 cases with a proposal for an additional panel of stains for diagnosis

Abstract

Desmoplastic melanoma (DM) is histologically characterized by a proliferation of spindle melanocytes dispersed in a collagenous stroma that can be mistaken for a variety of neoplasms. The purpose of this study was to analyze 40 cases of DM with a comprehensive panel of immunohistochemical markers (KBA.62, p16, Ezrin, WT-1, MITF-1, SOX-10, CD117, SOX-2, nestin, PNL2, p75, MART-1, gp100 and S100p) to obtain a more complete understanding of the potential use of these antibodies in the diagnosis of DM. We found that all cases of DM expressed p16, WT-1, SOX-10, nestin and S100p and 95% of cases expressed p75. There was variable expression with Ezrin, SOX-2, KBA.62, MART-1 and HMB-45. Most DMs did not express MITF-1, PNL2 and CD117. Conditions that may enter in the histologic differential diagnosis of DM, including dermal scars, fibromatosis and dermatofibromas were also studied. Nearly all control cases also stained positive for p16 but were negative for WT1, SOX10, nestin, p75 and S-100p, as well as for most of the other markers tested. We conclude that a panel of S-100p, WT1, SOX10, p75 and nestin may constitute the optimal panel with the most sensitive and specific combination of immunostain available for the diagnosis of DM.

SOX‐10 staining in dermal scars

“…SOX‐10 has been shown to be a more sensitive and specific melanocytic marker than S‐100 protein for cells of melanocytic and neural lineage . A study conducted by Plaza et al supports that SOX‐10 is a highly sensitive marker for the diagnosis of DM, as it was expressed in 100% of specimens (40 cases) in their study .…”

“…SRY‐related HMG‐box gene 10 ( SOX10 ) is a nuclear transcription factor that plays an important role in melanocytic cell differentiation and is commonly expressed in cells of melanocytic, neural, and myoepithelial lineages . SOX10 plays an important role in melanocyte development and has been found to be highly expressed in melanoma . The SOX‐10 immunohistochemical (IHC) stain is largely used as a specific and sensitive marker for melanocytes and neural tissues .…”

“…The SOX‐10 immunohistochemical (IHC) stain is largely used as a specific and sensitive marker for melanocytes and neural tissues . Melanocyte‐specific markers such as S100, HMB 45, and Melan A have been used to evaluate residual melanoma in the setting of desmoplastic melanoma (DM) and uveal melanoma . Recent studies have also showed that SOX‐10 is a sensitive and specific marker in the evaluation of DM .…”

“…Melanocyte‐specific markers such as S100, HMB 45, and Melan A have been used to evaluate residual melanoma in the setting of desmoplastic melanoma (DM) and uveal melanoma . Recent studies have also showed that SOX‐10 is a sensitive and specific marker in the evaluation of DM . Differentiating DM from excision scars based on histopathology alone can often be a challenge, which is further complicated by the fact that spindled fibroblasts and histiocytes within the scars lack consistent specific immunohistochemical (IHC) staining .…”

Errors in dermatology: desmoplastic melanoma – the amazing monster

“…Zur Beurteilung kutaner Spindelzellneoplasien muss daher ein Panel unterschiedlicher Differenzierungsmarker herangezogen werden. Da SOX10 und p75 hochspezifi sch sind und sich ihr Färbemuster leicht interpretieren lässt, sollten diese Marker zur Bestätigung der Diagnose DM eingesetzt werden [ 11 ] . Defi nitive immunhistochemische Merkmale wie der "CD34-Fingerabdruck" können bei der Differenzierung eines frühen DM von anderen neuralen Spindelzelltumoren ebenfalls hilfreich sein [ 12 ] .…”