Immunohistochemical analysis of CXCR4 expression in fibrohistiocytic tumors

Challenging Patterns of Atypical Dermatofibromas and Promising Diagnostic Tools for Differential Diagnosis of Malignant Lesions

Dermatofibroma (DF) or fibrous histiocytoma is one of the most frequent benign cutaneous soft-tissue lesions, characterized by a post-inflammatory tissue reaction associated with fibrosis of the dermis. Clinically DFs have a polymorphous clinical aspect from the solitary, firm, single nodules to multiple papules with a relatively smooth surface. However, multiple atypical clinicopathological variants of DFs have been reported and, therefore, clinical recognition may become challenging, leading to a more burdensome identification and sometimes to misdiagnosis. Dermoscopy is considered an important tool in DFs diagnosis, as it improves diagnostic accuracy for clinically amelanotic nodules. Although typical dermoscopic patterns are most frequently seen in clinical practice, there have also been some atypical variants described, mimicking some underlying recurrent and sometimes harmful skin afflictions. Usually, no treatment is required, although an appropriate work-up may be necessary in specific cases, such as in the presence of atypical variants or a history of recent changes. This narrative review's aim is to summarize current evidence regarding clinical presentation, positive and differential diagnosis of atypical dermatofibromas and also to raise awareness about the importance of specific characteristics of atypical variants to better differentiate them from malignant conditions.

Neurotrophin Receptors and Perineural Invasion: Analyses in Select Lineage-Unrelated Cutaneous Malignancies With a Propensity for Perineural Invasion

In this chapter, we parse the literature on neurotrophins that have been implicated in the pathogenesis of perineural invasion (PNI) in select lineage-unrelated malignancies. We also detail evidence linking neurotrophins and their receptors (TrkA, RET, p75NGFR, and NCAM) to the pathogenesis of PNI in desmoplastic melanoma and cutaneous squamous cell carcinoma-both malignancies with an established propensity for PNI. Lastly, the clinical potential of neurotrophins as receptors for targeted therapies is explored.

Close correlation between CXCR4 and VEGF expression and frequent CXCR7 expression in rhabdomyosarcoma

CXC chemokine receptor 4 (CXCR4) expression is reportedly correlated with both vascular endothelial growth factor (VEGF) expression and poor prognosis in a variety of cancers. Its relation to CXC chemokine receptor 7 (CXCR7) is also noted in several malignancies, including rhabdomyosarcoma (RMS) cell lines. However, the correlations between these chemokine receptors and angiogenic factors have not yet been adequately investigated in RMS clinical specimens. By immunohistochemistry, we assessed CXCR4, CXCR7, CC chemokine receptor 6, CC chemokine receptor 7, VEGF expression, microvessel density, and MIB-1 labeling index in 82 formalin-fixed RMS specimens, including 34 primary alveolar RMS and 44 primary embryonal RMS (ERMS). Twenty-six frozen samples were available for investigation by quantitative reverse transcription polymerase chain reaction to detect the messenger RNA expression levels of these molecules. We also evaluated their significance with respect to clinicopathological factors and patient survival rates. Primary RMS showed high expression of CXCR7 (83.1%) regardless of the histologic subtype. High cytoplasmic CXCR4 and high VEGF expression revealed significant correlations in both ERMS and alveolar RMS (P = .0051 and P = .0003, respectively). By univariate analysis of ERMS cases, the tumors with high VEGF expression showed significantly poor prognoses (P = .0017). High VEGF expression also was the independent adverse prognostic factor for ERMS. Because CXCR4, CXCR7, and VEGF are widely expressed in RMS, the combination of these antagonists may provide a potential target for molecular therapy.

Chemokine receptor CXCR4 is a novel marker for the progression of cutaneous malignant melanomas

The CXCR4/CXCL12 pathway has recently been reported to be involved in stimulating the metastasis of many different neoplasms, in which CXCR4 activates various phenomena such as chemotaxis, invasion, angiogenesis and proliferation. The purpose of this study was to analyze a possible association between the expression of chemokine receptors CXCR4, CCR6 and CCR7 with the clinicopathological features of cutaneous malignant melanoma, and to assess the usefulness of these chemokine receptors for diagnosis and prognosis. In our study, a percentage of immunoexpression of both CXCR4 and its ligands CXCL12 was associated with high clinical risk. In contrast, the patients with a low immunoexpression of CXCR4 and CXCL12 had low clinical risk. CCR6 and CCR7 immunoexpressions were also correlated with some clinical parameters, but seemed no more useful than CXCR4. These data suggest that the assessment of CXCR4 immunoexpression is a novel tool for predicting tumor aggressiveness in malignant melanomas, and in particular, a high immunoexpression percentage of CXCR4 and CXCL12 might be a sign of a poor prognosis.

IGFBP7, a novel immunohistochemical marker in differentiating dermatofibroma from dermatofibrosarcoma protuberans

BACKGROUND

Loss of insulin-like growth factor-binding protein 7 (IGFBP7) has been found to be a critical step in the development of melanoma and colon cancer. To our knowledge, immunostaining of IGFBP7 in various dermatofibrosarcoma protuberans (DFSP) and dermatofibroma (DF) has not been studied before.

OBJECTIVES

To assess the immunostaining of IGFBP7 in DFSPs and DFs and to ascertain whether IGFBP7 is superior to antibodies traditionally used in differentiating DFs from DFSPs.

METHODS

Immunohistochemical staining was performed on 28 cases of DFSP and 30 cases of DF, using antibodies to IGFBP7, CD34, factor XIIIa (FXIIIa), CD10 and stromelysin-3 (ST-3).

RESULTS

Six of 28 (21.4%) DFSP samples were positive for IGFBP7, whereas 28 of 30 (93.3%) DF samples were positive. CD34 was positive in 26 of 28 (92.9%) cases of DFSP and 4 of 30 (13.3%) cases of DF. FXIIIa staining was positive in 4 of 28 (14.3%) cases of DFSP and 28 of 30 (93.3%) cases of DF. CD10 staining was positive in 12 of 28 (42.9%) cases of DFSP and ST-3 staining was positive in 7 of 28 (25.0%) cases of DFSP. The preferential IGFP7 staining of DFSPs in comparison with DFs was statistically significant (P < 0.01).

CONCLUSIONS

We confirmed that IGFBP7 is a negative immunohistochemical marker for DFSPs and the combination with CD34, FXIIIa and ST-3 immunostaining could make the distinction more reliable.