BMC Cancer Case report A case repot of Merkel cell carcinoma on chronic lymphocytic leukemia: differential diagnosis of coexisting lymphadenopathy and indications for early aggressive treatment KI Papageorgiou*†1 and MG Kaniorou-Larai†1,2 BioMed Central Open Access Address: 1St Andrews Center of Burns and Plastic Surgery, Broomfield Hospital, Court Road, Chelmsford, CM1 7ET, UK and 2Plastic and Reconstructive Surgery Department, "G. Gennimatas" 6th IKA Oncological Hospital, 11473 Athens, Greece Email: KI Papageorgiou* - papageorgiouk@doctors.org.uk; MG Kaniorou-Larai - mkaniorou@yahoo.co.uk * Corresponding author †Equal contributors Published: 19 August 2005 BMC Cancer 2005, 5:106 doi:10.1186/1471-2407-5-106 This article is available from: http://www.biomedcentral.com/1471-2407/5/106 Received: 30 March 2005 Accepted: 19 August 2005 © 2005 Papageorgiou and Kaniorou-Larai; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC). Case presentation: A case report of an 84-year old male, who presented with an aggressively recurrent form of MCC on the lower lip, on the background of an 8-year history of untreated CLL. During the recurrences of MCC, coexisting regional lymphadenopathy, posed a problem in the differential diagnosis and treatment of lymph node involvement. Histopathology and immunoistochemistry showed that submandibular lymphadenopathy coexisting with the second recurrence of MCC, was due to B-cell small lymphocytic lymphoma. The subsequent and more aggressive recurrence of the skin tumor had involved the superficial and deep cervical lymph nodes. Surgical excision followed by involved field radiation therapy has been proven effective for both malignancies. Conclusion: MCC has a high incidence of regional lymphadenopathy at presentation (12–45%) and even when it arises on the background of chronic leucemia, lymphadenopathy at presentation should be managed agressively with elective lymph node dissection. We overview the postulated correlation between Merkel tumor and CCL, the differential diagnosis of regional lymphadenopathy during the recurrences of the skin tumor and the strategies of treatment Background MCC, is an uncommon tumor, which mostly occurs as an asymptomatic, solitary, firm and red-pink nodule. It has been linked to increased sun exposure [1], both in its ana- tomic and geographical distribution. Usually is nonulcer- ated and ranges from 0.8 to 4 cm in diameter [2,3]. Predominantly involves the head and neck region (65%) [4,5], followed by the upper extremities (18%), and the lower extremities (13%) [3]. The precice origin is still con- troversial. However, the Merkel cell (assumed to be a touch receptor) and the melanocyte are the cutaneous counterparts of the Amine Precurcor Uptake and Page 1 of 6 (page number not for citation purposes)