Dermatofibromas with Aberrant Expression of CD34 Protein: A Systematic Review and a Reappraisal of Clinicopathological Features and Histogenesis

Abstract

Background: Dermatofibromas (DFs) are benign fibrohistiocytic lesions that usually do not express CD34 protein. This study aimed to analyze the literature concerning the immunohistological and ultrastructural features of DFs. It also related these features to the histogenesis of these lesions. Methods: This study included a PubMed literature search for studies addressing the clinicopathological, ultrastructural, and immunohistochemical features of DFs. It also presented some current cases of CD34-negative DFs and a subset of these lesions with aberrant expression of this protein. Results: Analysis of the PubMed literature revealed that DFs with an aberrant expression of CD34 are rare tumors that commonly affect the extremities of adult females. Separating these tumors from dermatofibrosarcoma protuberans (DFSP, CD34-positive tumors) requires using a large panel of immunostains. Ultrastructurally, DFs are composed of diverse cell types, including cells with histiocytic, myofibroblastic, and fibroblastic features. An analysis of the DFs described by this study revealed that cases with an aberrant expression of CD34 protein had slightly high mean age and male sex predominance when compared to CD34-negative cases. The former commonly affected the extremities. There was no evidence of local recurrence or distant metastasis on follow-up. Conclusions: DFs have the potential to express CD34 protein, defining a rare aberrant phenotype, which was not associated with any differences in the outcome as compared to CD34-negative DFs.

The Burden of Skin Cancers in Saudi Arabia Through 2011-2022

“…In general, DFSP was detected in 4-6% of the detected skin cancers in KSA [ 2 , 25 , 26 , 28 ], which matched the percentage detected in the current study (5.5%). Although DFSP possesses female predominance at 20-40 years old [ 41 ], in the current study, it was recorded in four males and only one female but within the same age range. These types of tumors are composed of fibroblastic, myofibroblastic, and histiocytic cells with eosinophilic cytoplasm that are generally positive for CD68 and negative for CD34 [ 42 ].…”