P = .78, log-rank test) or other clinical features. Among 34 patients with available data, the group of patients with skin lesions at the time of presentation showed significantly higher levels of tumor cell p65 nuclear factor kB expression (2-tier scoring by immunohistochemistry, P = .023, x 2 test; confirma- tory Western blot in 14/34 patients), a feature often found in association with T-cell activation or lym- phoma progression. We conclude that skin involved by T-PLL, al- though common, is subjected to biopsy infrequently and reflects the aggressive disease course but likely does not represent a feature useful for distinguishing prognostic subsets. In addition, our analysis indi- cates that skin involvement in T-PLL is associated with a more diverse clinical and morphological spectrum than suggested by Magro et al. 1 In our experience, immunohistochemical staining for TCL1 is a useful diagnostic aid in discriminating T-PLL from other T-cell tumors. 3,5,6 However, a sub- set of T-PLL cases does not express TCL1. Interest- ingly, we observed a slightly higher number of cases with skin infiltration in these patients with TCL1- negative tumors. 3 Overall, T-PLL represents a heterogeneous entity both biologically and clinically as it also shows considerable clinicopathologic overlap with other T-cell tumors that involve peripheral blood and/or skin, such as Se ´zary syndrome. 3 Given the diagnostic difficulties and therapeutic challenges in T-PLL, 7 refined systematic analyses are needed. Marco Herling, MD, a,b Jose R. Valbuena, MD, a,c Dan Jones, MD, PhD, a and L. Jeffrey Medeiros, MD a Department of Hematopathology, The University of Texas, M. D. Anderson Cancer Center, Houston, a the Department of Hematology/Medical Oncology, Cologne University, Germany, b and Anatomic Pathology, Pontificia Universidad Catolica de Chile c Supported by a DFG young investigator grant (HE3553/2-1) to M.H. Conflicts of interest: None declared. Correspondence to: Marco Herling, MD, Hematol- ogy/Medical Oncology, University of Cologne, Kerpenerstrasse 62, LFI, Level 4, Room 058a, Cologne 50931, Germany E-mail: marco.herling@uk-koeln.de REFERENCES 1. Magro CM, Morrison CD, Heerema N, Porcu P, Sroa N, Deng AC. T-cell prolymphocytic leukemia: an aggressive T cell malignancy with frequent cutaneous tropism. J Am Acad Dermatol 2006; 55:467-77. 2. Matutes E, Brito-Babapulle V, Swansbury J, Ellis J, Morilla R, Dearden C, et al. Clinical and laboratory features of 78 cases of T-prolymphocytic leukemia. Blood 1991;78:3269-74. 3. Herling M, Khoury JD, Washington LT, Duvic M, Keating MJ, Jones D. A systematic approach to diagnosis of mature T-cell leukemias reveals heterogeneity among WHO categories. Blood 2004;15:328-35. 4. Mallett RB, Matutes E, Catovsky D, Maclennan K, Mortimer PS, Holden CA. Cutaneous infiltration in T-cell prolymphocytic leukemia. Br J Dermatol 1995;132:263-6. 5. Valbuena JR, Herling M, Admirand JH, Padula A, Jones D, Medeiros LJ. T-cell prolymphocytic leukemia involving extra- medullary sites. Am J Clin Pathol 2005;123:456-64. 6. Herling M, Teitell MA, Shen RR, Medeiros LJ, Jones D. TCL1 expression in plasmacytoid dendritic cells (DC2) and the related CD41 CD561 blastic tumors of skin. Blood 2003;101:5007-9. 7. Ravandi F, O’Brien S, Jones D, Lerner S, Faderl S, Ferrajoli A, et al. T-cell prolymphocytic leukemia (T-PLL): a single institution experience. Clin Lymphoma Myeloma 2005;6:234-9. doi:10.1016/j.jaad.2007.02.034 Case of multiple verrucous carcinomas responding to treatment with acetretin more likely to have been a case of verrucous psoriasis To the Editor: In the February 2007 case reports supplement, Kuan et al 1 described a case of multiple verrucous carcinomas that responded to treatment with acetretin. Both the clinical and histologic find- ings, however, cause us to question the diagnosis and wonder whether this may well be a case of psoriasis. Multiple verrucous carcinomas occurring in the same patient, as acknowledged by the authors, are rare. The clinical description and accompanying images of hyperkeratotic plaques over both feet, ankles and the left thigh persisting for 3 years is very atypical. Verrucous carcinoma on the feet typically appears as warty, well-circumscribed lesions with a cauliflower-like appearance that are often mistaken for verrucae and have a predilection for the weight- bearing areas of the soles. 2 The histologic diagnosis of verrucous carcinoma is difficult. The authors stated that 6 biopsy speci- mens were obtained from different sites and that ‘‘... all specimens showed marked parakeratosis, neo- plastic proliferation, and downward invasion of epidermal keratinocytes with a blunt border and a pushed down, bulldozing appearance.’’ Verrucous carcinoma is histologically characterized by blunt papillary projections of well-differentiated epithe- lium, with tumor islands in the thickened papillary dermis supported by edematous, nonreactive stroma. The image of the biopsy specimen supplied only visualized the epidermis and minimal dermis JAM ACAD DERMATOL SEPTEMBER 2007 534 Letters