A unique case of merkel cell carcinoma and CLL presenting in a single cutaneous lesion (collision tumour).

[Guest guest]

BlankA unique case of merkel cell carcinoma and chronic lymphocytic leukaemia

presenting in a single cutaneous lesion (collision tumour).

H Zhang, G Gupta, XY Yang, R Rosenbluth, and PK Bhattacharyya

BMJ Case Reports, January 1, 2009; 2009: .

University of Medicine and Dentistry of New Jersey, Pathology, E156, 185 South

Orange Avenue, Newark, NJ 07103, USA.

A 58-year-old man with 10 year history of chronic lymphocytic leukaemia (CLL)

presented with a bulging mass (3.2?1.6?1.5 cm) in the right anterior abdominal

wall. On microscopic examination the mass was found to be an epithelial neoplasm

in the background of lymphoid proliferation. The epithelial cells were of

moderate size, with scant cytoplasm and round nuclei, forming glandular,

alveolar or sheet-like structures. These cells were immunoreactive for

cytokeratin 20, chromogranin and synaptophysin. The above findings supported a

diagnosis of Merkel cell carcinoma (MCC). The background small lymphocytes

expressed phenotypic markers of B cells (CD20) and CD5, consistent with his

known diagnosis of CLL. The incidence of a patient with a known history of CLL

who develops a secondary MCC is rare. This is believed to be the second case

report of a single lesion containing CLL and MCC.

PMID: 21686502