Cutaneous and Superficial Soft Tissue CD34+ Spindle Cell Proliferation

Context.-Cutaneous and superficial soft tissue spindle cell proliferations with CD34 expression represent a unique heterogeneous group of lesions. They can pose diagnostic challenges for unaware pathologists in their daily practice. Objective.-To review selected entities of CD34(+) spindle cell proliferations in the skin and superficial soft tissue. The effective diagnostic approaches using clinical, histopathologic, and immunophenotypical findings are discussed within a broad spectrum of differential diagnosis. Data Sources.-All information used in the article is obtained from published literature by PubMed search and Internet-based search engines. The authors' collective experience and real-life examples are also used. Conclusions.-Spindle cell proliferations with CD34 positivity can be worked up to a definitive diagnosis by using clinical, histopathologic, and immunophenotypical findings. Familiarity with these entities helps pathologists make the accurate diagnosis.