Stromelysin 3 expression: a useful marker for the differential diagnosis dermatofibroma versus dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans: a case report of an abdominal wall mass and review of the literature

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing malignancy that often presents with an ambiguous clinical presentation due to its nonspecific findings. We present the case of a 41-year-old male who presented with a slow-growing mass on his abdomen that became protuberant and firm, prompting his desire to pursue excision. Upon return of histologic examination, the specimen was noted to be DFSP. DFSP is a rare cutaneous neoplasm that originates from the dermis and invades the underlying tissue creating a classic protuberant appearance. In some cases, chemotherapy and radiation may be indicated based on margins and locations. The sarcoma is notoriously complicated with early recurrence, making the disease process difficult to control. Surgeons should be familiar with this malignancy due to the indication of additional nonsurgical treatments and the necessity for long-term follow-up for surveillance of recurrence.

ETS-related Gene (ERG) is Differentially Expressed in Dermatofibroma (Fibrous Histiocytoma) as Compared With Dermatofibrosarcoma Protuberans and Hypertrophic Scars: A Pilot Immunohistochemical Study

Immunohistochemical staining can be of great utility in differentiating various cutaneous spindle cell neoplasms, particularly when the histomorphologic appearance of the lesions is inconclusive. Nuclear staining for ETS-related gene (ERG), a highly sensitive endothelial cell marker, has seldom been studied in the context of cutaneous spindle cell neoplasms. Little is known about its specificity for vascular differentiation. In this pilot study, immunohistochemical analysis for ERG was performed on 15 dermatofibromas (DF), 10 keloids, and 9 dermatofibrosarcoma protuberans (DFSP) tumors. Consistent nuclear expression of ERG was found in DF [100% (15/15) of the lesions demonstrated >50% labeling of tumor cells with moderate to strong intensity]. However, ERG expression was largely absent in DFSP [89% (8/9) of the lesions demonstrating <50% labeling staining, generally of mild intensity] and hypertrophic scars-keloids [80% (8/10) without expression]. On the basis of the results of this pilot study, immunohistochemical staining for ERG may prove useful in helping to differentiate DF from DFSP and hypertrophic scars in the context of partial biopsy sampling. If replicated in a larger number of samples, this finding could mitigate the use of costly sequencing panels and potentially avoid unnecessary reexcisions in certain contexts.

Phosphohistone-H3 and Ki67: Useful Markers in Differentiating Dermatofibroma From Dermatofibrosarcoma Protuberans and Atypical Fibrohistiocytic Lesions

Dermatofibromas (DF) are common, benign, skin tumors, usually easily differentiated from dermatofibrosarcoma protuberans (DFSP) by the presence of a relative low cellularity, lesser degree of infiltration of subcutaneous tissue, and immunohistochemical pattern (eg, FXIIIa in DF and CD34 in DFSP). Atypical fibrohistiocytic lesions (AFL) have features intermediate to DF and DFSP (trunk location, storiform pattern, infiltration of the subcutaneous tissue, and focal expression of both CD34 and Factor XIIIa). It is unclear if mitotic counts/degree of proliferation is helpful to distinguish DF from DFSP. To study the mitotic rate and proliferation index in DF, AFL/DFSP, anti-ki67, and anti-PHH3 were performed on 10 cases of DF (including 4 cellular DF), 10 standard DFSP, and 2 AFL. The proliferation index and mitotic figures were counted per square millimeter in a "hotspot" (in a fashion similar to mitotic counts in melanoma). All cases of DF showed much higher Ki67 proliferation index (P = 0.0001) along with increased mitotic figures both on H&E and with anti-PHH3 (P = 0.0001) when compared to AFL/DFSP. Our data indicate that DF has a higher proliferation index and mitotic counts when compared to superficial/peripheral portion of AFL and DFSP. This finding may be helpful in the differential diagnosis among these fibrohistiocytic lesions.

Immunohistochemistry in dermatopathology

CONTEXT

Immunohistochemistry is not a diagnostic test but a highly valuable tool that requires interpretation within a context.

OBJECTIVE

To review the current status and limitations of immunohistochemistry in dermatopathology.

DATA SOURCES

English-language literature published between 1980 and 2014.

CONCLUSIONS

Although immunohistochemistry is rarely completely specific or sensitive, it is an important adjunctive technique in dermatopathology and can be helpful in a series of diagnostic dilemmas.

Immunohistochemical markers in fibrohistiocytic lesions: factor XIIIa, CD34, S-100 and p75

BACKGROUND

The distinction between dermatofibroma (DF), dermatofibrosarcoma protuberans (DFSP), and other benign and malignant cutaneous spindle cell lesions frequently requires immunohistochemical staining. CD34 and factor XIIIa are the most commonly used immunostains; however, they may exhibit aberrant expression and introduce the potential for misdiagnosis. There is some data supporting that p75 and S100A6 may be additional helpful immunohistochemical markers.

METHODS

We undertook a large case series examining the use of CD34 and factor XIIIa as well as p75 and S100A6 in DF, cellular DF, DFSP, indeterminate fibrohistiocytic lesion, and scar.

RESULTS

As expected, CD34 stained DFSP, although it was usually negative in DF. Factor XIIIa was generally positive in DF and negative in DFSP. There were exceptions in both cases of DF and DFSP. S100A6 was routinely negative in all entities studied. P75 was negative in all cases except DFSP, approximately half of which showed weak and/or patchy positivity.

CONCLUSIONS

We conclude that to date, CD34 and factor XIIIa remain the most reliable immunohistochemical markers for DF and DFSP.

Genetic aberrations in imatinib-resistant dermatofibrosarcoma protuberans revealed by whole genome sequencing

Dermatofibrosarcoma protuberans (DFSP) is a very rare soft tissue sarcoma. DFSP often reveals a specific chromosome translocation, t(17;22)(q22;q13), which results in the fusion of collagen 1 alpha 1 (COL1A1) gene and platelet-derived growth factor-B (PDGFB) gene. The COL1A1-PDGFB fusion protein activates the PDGFB receptor and resultant constitutive activation of PDGFR receptor is essential in the pathogenesis of DFSP. Thus, blocking PDGFR receptor activation with imatinib has shown promising activity in the treatment of advanced and metastatic DFSP. Despite the success with targeted agents in cancers, acquired drug resistance eventually occurs. Here, we tried to identify potential drug resistance mechanisms against imatinib in a 46-year old female with DFSP who initially responded well to imatinib but suffered rapid disease progression. We performed whole-genome sequencing of both pre-treatment and post-treatment tumor tissue to identify the mutational events associated with imatinib resistance. No significant copy number alterations, insertion, and deletions were identified during imatinib treatment. Of note, we identified newly emerged 8 non-synonymous somatic mutations of the genes (ACAP2, CARD10, KIAA0556, PAAQR7, PPP1R39, SAFB2, STARD9, and ZFYVE9) in the imatinib-resistant tumor tissue. This study revealed diverse possible candidate mechanisms by which imatinib resistance to PDGFRB inhibition may arise in DFSP, and highlights the usefulness of whole-genome sequencing in identifying drug resistance mechanisms and in pursuing genome-directed, personalized anti-cancer therapy.

Matrix metalloproteinases in cancer: their value as diagnostic and prognostic markers and therapeutic targets

Biomarkers are used as tools in cancer diagnostics and in treatment stratification. In most cancers, there are increased levels of one or several members of the matrix metalloproteinases (MMPs). This is a family of proteolytic enzymes that are involved in many phases of cancer progression, including angiogenesis, invasiveness, and metastasis. It has therefore been expected that MMPs could serve as both diagnostic and prognostic markers in cancer patients, but despite a huge number of studies, it has been difficult to establish MMPs as cancer biomarkers. In the present paper, we assess some of the challenges associated with MMP research as well as putative reasons for the conflicting data on the value of these enzymes as diagnostic and prognostic markers in cancer patients. We also review the prognostic value of a number of MMPs in patients with lung, colorectal, breast, and prostate cancers. The review also discusses MMPs as potential target molecules for therapeutic agents and new strategies for development of such drugs.

Dermatofibrosarcoma protuberans: Our experience of 59 cases

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue tumor with intermediate malignancy. It is initially located on the skin from where it is able to infiltrate the deep structures and has a tendency to recur locally following inadequate excision. A t(17;22)(q22;q13) chromosome trans-location is the main cytogenetic alteration responsible for the onset of DFSP. Treatment options include complete surgical excision by performing conventional surgery with wide margins (>3 cm) or Mohs micrographic surgery. A retrospective study was conducted in our Department of Plastic and Reconstructive Surgery and all data were collected from medical records of 59 DFSP patients within this department from 1999 to 2011. A total of 13 of 59 (22%) cases were treated with conventional excision; 3 (5%) cases resulted in tumor-free margins, 8 (14%) cases required surgical revision and 2 (3%) cases lead to recurrence. A total of 46 of 59 (78%) cases were treated with wide excision; 43 (73%) cases resulted in tumor-free margins, 3 (5%) cases required surgical revision and 0 (0%) cases lead to recurrence. In conclusion, the data collected reveal the controversy surrounding the adoption of general guidelines regarding safe margins. Further studies are required to investigate the possibility of obtaining genotypically altered margins from margins that may appear phenotypically healthy.

Expression of MMP-2, MMP-9 and MMP-11 in dermatofibroma and dermatofibrosarcoma protuberans

Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) are the spindle cell mesenchymal neoplasms of the dermis and subcutis. Their histogenesis still remains uncertain and controversial. Traditionally, CD34 and factor XIIIa or other markers have been widely used to distinguish these two diseases. However, the results of these markers reveal overlapping and they lack specificity. Formalin-fixed, paraffin-embedded blocks were collected from the biopsied cases in Kaohsiung Medical University Hospital in Taiwan between 2004 and 2006. This study included 19 cases of DF and 17 cases of DFSP. Immunohistochemical analysis using antibodies CD34, matrix metalloproteinases (MMP)-2, MMP-9, and MMP-11 was performed. We found that the expression of CD34, MMP-2 and MMP-11 shows significant statistical differences in Immunohistochemistry (IHC) study positive or negative reactivity (positive of CD34 in DFSP and positive of MMP-2 and MMP-11 in DF; p=0.03, p<0.001, and p<0.001, respectively) between DF and DFSP. The result for expression of MMP-9 reveals no differences. The results indicate that the pathogenesis of DF and DFSP are affected by different expressions of extracellular matrix proteins. Metalloproteinases may play a direct role in these two diseases. Since no single marker can completely distinguish DF from DFSP, a combination of more than two or three stains may elevate the accuracy of diagnosis.

Stromelysin-3 expression in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans: comparison with factor XIIIa and CD34

BACKGROUND

The distinction between dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) is a well-known challenge for dermatopathologists. Immunohistochemical stains have been used to augment routine histological examination to aid in differentiating DF from DFSP. Stromelysin-3 (ST3) is a member of the matrix metalloproteinase (MMP) family, MMP-11, which is expressed in the skin during wound healing and in the stroma of basal cell carcinoma. Recent studies demonstrated that DFs expressed ST3, whereas DFSPs were only rarely ST3 positive.

OBJECTIVES

To assess the expression of ST3 in DF and DFSP and to ascertain whether ST3 is superior to factor XIIIa or CD34 in differentiating DF from DFSP, by comparison with factor XIIIa and CD34 expression.

METHODS

Immunohistochemical staining was performed on 23 cases of DF and 17 cases of DFSP, using antibodies to ST3, factor XIIIa and CD34.

RESULTS

ST3 was expressed in all cases of DF (23 of 23) but only one case showed weakly positive staining in DFSP (one of 17). The mean +/- SD ST3 immunohistochemistry (IHC) score in DF was 4.52 +/- 0.67. The sensitivity of ST3 was 100% and the specificity was 94%. Factor XIIIa was expressed in all cases of DF (23 of 23) and in five of the 17 DFSPs. The mean +/- SD factor XIIIa IHC score in the DFs was 4.43 +/- 0.73. The sensitivity of factor XIIIa was 100% and the specificity was 71%. CD34 was expressed in four of the 23 DFs and 16 of the 17 DFSPs. The mean +/- SD CD34 IHC score in the DFSPs was 4.41 +/- 1.37. The sensitivity of CD34 was 94% and the specificity was 83%.

CONCLUSIONS

Immunohistochemical staining with a commercial anti-ST3 antibody can be successfully carried out in routine dermatopathology. We confirmed that ST3 is a positive marker for DF and that ST3 staining might be more reliable than factor XIIIa staining in differential diagnosis of DF and DFSP. As the present study showed that ST3 was not absolutely negative in all cases of DFSP, the combination with CD34 immunostaining could make the distinction more reliable.

Dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is a soft tissue neoplasm of intermediate malignancy that is initially localized to the skin from where it can invade deep structures (fat, fascia, muscle and bone). It is the most frequent fibrohistiocytic tumor, comprising approximately 1.8 % of all soft tissue sarcomas and 0.1 % of all cancers. It has an estimated incidence of 0.8-5 cases per one million persons per year. Treatment of localized disease consists in complete surgical excision of the lesion by conventional surgery with wide margins (>3 cm) or by micrographic Mohs surgery. Although the cases of metastatic DFSP do not reach 5 % of the total, almost all of them appear after previous local relapses. The prognosis for metastatic cases is very poor with a survival of less than 2 years following detection of metastatic disease. Patients with locally advanced DFSP are not candidates for an initial radical surgical therapy therefore neoadyuvant treatment is required prior to surgery in order to reduce tumor burden. In this regard, chemotherapy and radiotherapy have not been highly efficacious so it is necessary to consider new alternatives. The demonstration of the oncogenic power of the translocation COL1A1-PDGFB in DFSP has allowed the successful introduction of drug therapy with antagonists of the PDGFB receptor for metastatic or locally advanced cases.

Dermatofibrosarcoma Protuberans of the Forehead and Scalp with Involvement of the Outer Calvarial Plate: Multistaged Repair with the Use of Skin Expanders

BACKGROUND AND OBJECTIVE

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive and infiltrative tumor that requires Mohs' micrographic surgery or wide excision to treat. Adequate excision often leaves a cosmetic disfiguring defect, particularly if the tumor is located on the head and neck. Complex defects of the face present special problems, such as distortion, ectropion, and retraction of normal tissues.

PATIENT AND METHODS

We present a case of an infiltrating DFSP of the forehead and scalp in a young woman. The tumor was removed, and the defect was reconstructed with multistaged repair, which included bone coverage, local and regional flaps, and the use of expanders.

RESULTS

A multistaged repair was performed with good clinical outcome and satisfactory cosmetic results.

CONCLUSION

Multistaged repair of the face is a viable alternative surgical approach to preserve facial contours and minimize distortion in the treatment of DFSP. This case illustrates the degree of complexity that the treatment of DFSP may involve.

From a unique cell to metastasis is a long way to go: clues to stromelysin-3 participation

Stromelysin-3 (ST3) overexpression is associated with poor patient clinical outcome in numerous carcinomas. The ST3 is expressed by peritumoral fibroblast-like cells. Review of the literature shows that ST3 is an active partner of cancer cells along the whole natural cancer history, and is essential for optimal tumor development as it reduces death of cancer cells invading adjacent connective tissues at the primary tumor site. Paradoxically, ST3 lowers metastasis development in vivo in mice. However, this beneficial effect does not counterbalance the deleterious anti-apoptotic function of ST3.

Childhood dermatofibrosarcoma protuberans: role of preoperative imaging

Dermatofibrosarcoma protuberans (DFSP) is especially challenging to recognize and diagnose in children. Prompt and definitive treatment is essential based on the tumor's high rate of recurrence. Our purpose is to increase physician awareness and recognition of DFSP in the pediatric population with the largest case series of childhood DFSP to our knowledge thus reported in the literature. We also propose that magnetic resonance imaging (MRI) may be useful in the preoperative assessment. The records of 10 patients with primary DFSP between the ages of 8 months and 16 years were reviewed. Only 1 of 10 patients was given the correct diagnosis at the initial medical evaluation. Of the 10 cases, 5 were congenital. The average delay in diagnosis was 5 years. Of the patients, 5 had preoperative MRI to delineate the size and extent of the tumor. In the two cases with the largest tumors preoperative MRI significantly altered surgical planning and execution. Thus, preoperative MRI may be helpful in planning for successful surgical clearance of large tumors and preventing local recurrence. All 10 cases were treated with Mohs micrographic surgery and no recurrences were noted with a follow-up range of 6 weeks to 17 years.

Immunohistochemical expression of matrix metalloproteinases 1, 2, 9, and 14 in dermatofibrosarcoma protuberans and common fibrous histiocytoma (dermatofibroma)

CONTEXT

Common fibrous histiocytoma (cFH) or dermatofibroma and dermatofibrosarcoma protuberans (DFSP) are 2 spindle cell mesenchymal tumors that are distinguished in part by their microscopic growth patterns and clinically by the greater propensity for DFSP to recur. Matrix metalloproteinases (MMPs) potentially play a role in modulating the growth patterns of cFH and DFSP by remodeling the extracellular matrix.

OBJECTIVE

To evaluate the immunohistochemical (IHC) expression of MMP-1, MMP-2, MMP-9, and MMP-14 in DFSP and cFH, because (1) MMP-1, MMP-2, MMP-9, and MMP-14 are synthesized by dermal fibroblasts, the major constituent of DFSP and cFH; and (2) platelet-derived growth factor B, which is overexpressed in most examples of DFSP because of t(17;22), activates ets-1, a transcription factor that regulates molecules associated with tumor invasion and metastasis, including MMP-1, MMP-3, and MMP-9.

DESIGN

Immunohistochemical studies were performed on archived, formalin-fixed, paraffin-embedded tissue of DFSP (n = 48) and cFH (n = 47).Results.-Significant IHC expression (>10% of tumor cells) in cFH included MMP-14 (27 [59%] of 46 tumors positive), MMP-2 (21 [47%] of 45 tumors positive), MMP-9 (9 [20%] of 45 tumors positive), and MMP-1 (6 [13%] of 46 tumors positive). No DFSPs showed significant IHC expression of any of the MMPs evaluated. However, anti- MMP-2 highlighted a rich microvascular element within deep tumor tissue present in 81% of DFSPs with a prominent subcutaneous component.

CONCLUSION

Our IHC results indicate that MMP-1 and MMP-9 are not up-regulated in DFSP. Convincing expression of MMP-14 in cFH suggests that this MMP may affect the growth pattern of the lesion, perhaps by activating MMP-2 expression in tumor cells. In DFSP, MMP-2 may play a role in tumor angiogenesis.

Differential Expression of HMGA1 and HMGA2 in Dermatofibroma and Dermatofibrosarcoma Protuberans: Potential Diagnostic Applications, and Comparison with Histologic Findings, CD34, and Factor XIIIa Immunoreactivity

The histologic distinction of dermatofibrosarcoma protuberans (DFSP) and dermatofibroma (DF) may be difficult, especially in the case of DF extending into the subcutaneous fat (deep DF). CD34 and Factor XIIIa staining is commonly used in separating DF from DFSP, but is not always helpful. HMGA1 and HMGA2 genes, members of the high mobility group protein family genes, encode proteins that act as architectural transcription factors and are frequently dysregulated in a variety of benign or locally aggressive mesenchymal tumors. In this study, we evaluated the immunoreactivity of HMGA1 and HMGA2 in a series of DF and DFSP to determine the possible utility for these markers in the differential diagnosis of these two entities. Immunohistochemical stains were performed on paraffin-embedded tissues from 22 cases of DF, including 14 cases of deep DF and 14 cases of DFSP, using antibodies against HMGA1 and HMGA2. CD34 and Factor XIIIa immunoreactivity was also evaluated in these lesions and compared with the results of HMGA immunostaining. Immunopositivity for both HMGA1 and HMGA2 was seen in 21of 22 (96%) DFs, but in only 3 (21%) and 1 (7%) of 14 DFSPs, respectively. While 100% of DFSP stained for CD34, 36% of DF also labeled for CD34. The immunoreactivity of HMGA1 and HMGA2 in DF was generally strong and diffuse, in contrast to weak and focal staining seen in DFSP. The proportion of cases with positive immunoreactivity for both markers was significantly higher in DF and in deep DF than in DFSP (P < 0.001). We conclude that HMGA1 and HMGA2 expression can be used to distinguish DF from DFSP with a degree of accuracy that is fully equivalent to that of Factor XIIIa and CD34.

Genetics of dermatofibrosarcoma protuberans family of tumors: from ring chromosomes to tyrosine kinase inhibitor treatment

Dermatofibrosarcoma protuberans (DP) is a rare, slow-growing, infiltrating dermal neoplasm of intermediate malignancy, made up of spindle-shaped tumor cells often positive for CD34. The preferred treatment is wide surgical excision with pathologically negative margins. At the cytogenetic level, DP cells are characterized by either supernumerary ring chromosomes, which have been shown by using fluorescence in situ hybridization techniques to be derived from chromosome 22 and to contain low-level amplified sequences from 17q22-qter and 22q10-q13.1, or t(17;22), that are most often unbalanced. Both the rings and linear der(22) contain a specific fusion of COL1A1 with PDGFB. Similar to other tumors, the COL1A1-PDGFB fusion is occasionally cryptic, associated with complex chromosomal rearrangements. Although rings have been mainly observed in adults, translocations have been reported in all pediatric cases. DP is therefore a unique example of a tumor in which (i) the same molecular event occurs either on rings or linear translocation derivatives, (ii) the chromosomal abnormalities display an age-related pattern, and (iii) the presence of the specific fusion gene is associated with the gain of chromosomal segments, probably taking advantage of gene dosage effects. In all DP cases that underwent molecular investigations, the breakpoint localization in PDGFB was found to be remarkably constant, placing exon 2 under the control of the COL1A1 promoter. In contrast, the COL1A1 breakpoint was found to be variably located within the exons of the alpha-helical coding region (exons 6-49). No preferential COL1A1 breakpoint and no correlation between the breakpoint location and the age of the patient or any clinical or histological particularity have been described. The COL1A1-PDGFB fusion is detectable by multiplex RT-PCR with a combination of forward primers designed from a variety of COL1A1 exons and one reverse primer from PDGFB exon 2. Recent studies have determined the molecular identity of "classical" DP, giant cell fibroblastoma, Bednar tumor, adult superficial fibrosarcoma, and the granular cell variant of DP. In approximately 8% of DP cases, the COL1A1-PDGFB fusion is not found, suggesting that genes other than COL1A1 or PDGFB might be involved in a subset of cases. It has been proposed that PDGFB acts as a mitogen in DP cells by autocrine stimulation of the PDGF receptor. It is encouraging that inhibitory effects of the PDGF receptor tyrosine kinase antagonist imatinib mesylate have been demonstrated in vivo; such targeted therapies might be warranted in the near future for treatment of the few DP cases not manageable by surgery.