Scalp Involvement in Primary Cutaneous Lymphomas-An Update on Clinical Presentation, Diagnostics, and Management.

Primary cutaneous lymphomas (PCLs) constitute a heterogeneous group of rare diseases. Previously, few studies have focused on the aspect of scalp involvement by PCLs. The objective of this study was to analyze the clinical presentation, diagnostic pathways, and treatment methods in patients diagnosed with scalp PCLs. A comprehensive literature review was conducted using the PubMed database, with the search terms "scalp" AND "cutaneous lymphoma", "folliculotropic mycosis fungoides" AND "scalp", "trichoscopy" AND "lymphoma", and "dermoscopy" AND "scalp" AND "lymphoma." The search was limited to articles published from database inception to May 2, 2024. Based on the title and abstract analysis, we included articles on PCLs involving the scalp. After a thorough review of the full manuscripts, several were excluded due to irrelevance, the absence of essential clinical data, discrepancies in patient age, gender, and diagnosis, and a lack of information pertinent to scalp PCLs. The literature search identified 1482 patients with scalp involvement in PCLs. Of the total number of cases, 1096 were diagnosed with B-cell PCLs, 384 with T-cell PCLs, and two cases lacked a precise PCL diagnosis. Primary cutaneous follicle center lymphoma was the most frequently reported B-cell PCL of the scalp, while mycosis fungoides was the most common T-cell PCL. Alopecia was observed in 69.0% of the patients analyzed, with the most prevalent form being non-scarring focal alopecia. It is imperative to consider the scalp in patients with PCLs, particularly in light of the knowledge that some lymphomas affecting the scalp exhibit a higher degree of aggressiveness.