MORE THAN JUST INFLAMMATION: INITIAL DIAGNOSIS OF CHRONIC LYMPHOCYTIC LYMPHOMA FOUND IN A ROUTINE EXCISION OF SQUAMOUS CELL CARCINOMA Andrew LJ Dunn, MD1; Daisy V Alapat, MD1; Sara C Shalin, MD, PhD1, Jennifer R Kaley, MD1; Jerad m Gardner, MD1 1Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 INTRODUCTION FINDINGS Chronic lymphocytic leukemia (CLL) is a low-grade hematological malignancy and is the most common leukemia in developed countries. Patients with CLL have been found to have a higher incidence of squamous cell carcinoma (SCC) relative to the general population. We present a case of CLL first diagnosed in an excision for SCC. PRESENTATION 59 year old male with a past medical history of multifocal SCC of the frontal scalp and left temple presents for wide local excision of a 4.1 x 3.9 cm ulcerative lesion of the right dorsal hand. Magnetic resonance imaging (MRI) showed 1 cm extension with lobulated contours that reached the extensor digitorum tendons. A B C RESULTS/DISCUSSION Well to moderately differentiated SCC was found invading to a depth of 8 mm and into tendons. Multifocal deposits of uniform small round lymphocytes were found throughout the dermis and subcutaneous tissue. Immunohistochemical staining (***) was consistent with CLL. Follow up bone marrow and lymph node biopsies showed involvement by CLL. Careful examination of atypical inflammation is vital as it may reveal underlying lymphoproliferative malignancies. In the setting of concomitant CLL and SCC, higher recurrence rates of SCC may occur. ? Move the 40x to the top left Show CD 20  CD5 C -4x D – 20x E, F -20x D E F 1. Brewer JD, Habermann TM, and Shanafelt TD. Lymphoma-associated skin cancer: incidence, natural history, and clinical management. Int J Dermatol. 2014 Mar;53(3):267-74. 2. Smoller BR, and Warnke RA. Cutaneous infiltrate of chronic lymphocytic leukemia and relationship to primary cutaneous epithelial neoplasms. J Cutan Pathol. 1998: 25; 160-164. 3. Agnew KL, Ruchlemer R, Catovsky D, Matutes E, and Bunker CB. Cutaneous findigns in chronic lymphocytic leukaemia. Br J Dermatol. 2004; 150: 1129-1135. Figure 1 Low power view showing superficial ulcer with invasive squamous cell carcinoma and adjacent inflammation (A, 40x original magnification). Lobules of small monotonous lymphocytes involve the subcutaneous adipose tissue (B, 40x original magnification). Higher power view shows monotonous lymphoid population infiltrating adipocytes (C, 400x original magnification). Intermediate power view shows the same monotonous cell population abutting invasive carcinoma (D, 200x original magnification). These cells coexpress CD5 and CD20 (E and F, respectively) NOTHING TO DISCLOSE