Kim DH, Medeiros LJ, Aung PP, et al. - Researchers sought to describe the histologic and immunohistochemical features of mantle cell lymphoma (MCL) involving skin. Thirty-seven skin specimens involved by MCL were reported; these represent 1.4% of total MCL biopsy specimens in their institution. Skin involvement was presented at the median age of 66 years (range, 36 to 85 y) and there was a male predilection of 2.7 to 1. The skin of extremities was the most frequently involved site, in 59.3% of patients, and advanced stage (III/IV) disease was identified in 30 (81.1%) patients. Skin lesions as the first manifestation of MCL were presented by 11 (29.7%) patients presented and 26 (70.3%) patients presented skin lesions as relapse or progression of previously documented MCL and despite therapy for systemic MCL. Microscopically, in all cases, the epidermis was spared with a grenz zone. The most common architectural pattern was a diffuse pattern of involvement (66.7%). Aggressive variants vs classic variant MCL displayed higher Ki-67 proliferation rate (median 90% vs 20%). The overall survival was inferior among patients with aggressive variant MCH vs those with classic variant MCL (median: 59 vs 155.8 mo). In summary, skin involvement rarely occurs in MCL and it correlates with relapse or progression of disease, aggressive morphologic features, and a poorer prognosis.