Monday, April 1, 2013

First description of Merkel Cell polyomavirus DNA detection in a patient with Stevens-Johnson syndrome.

First description of Merkel Cell polyomavirus DNA detection in a patient with Stevens-Johnson syndrome.

May 2013


Institute for Maternal and Child Health, IRCCS Burlo Garofolo, University of Trieste, Trieste, Italy.


Merkel Cell polyomavirus (MCPyV), a ubiquitous DNA tumor virus, has been found to be associated with Merkel cell carcinoma and chronic lymphocytic leukaemia while other associations are still being explored. MCPyV sequences have also been detected in normal tissues of tumor patients and in the blood of healthy donors. This report documents a new MCPyV association with the Stevens-Johnson syndrome, a rare immune-modulated mucocutaneous process particularly associated with specific drugs and infective agents. A high MCPyV viral load was detected simultaneously in fluid from skin lesions (2.0 × 10(4) copies/ml) and in matched blood (7.4 × 10(5) copies/ml) from a young adult patient after bone marrow transplant for a relapsed T-cell acute lymphatic leukaemia. MCPyV clearance concurred with the complete resolution of skin lesions after 5 days of cidofovir treatment. DNA sequencing classified the amplicons as the European/Italian MKL-1 strain. Given its ubiquitous nature, MCPyV could account for part of Stevens-Johnson syndrome idiopathic cases. J. Med. Virol. 85:918-923, 2013.

Merkel cell carcinoma with divergent differentiation: histopathological and immunohistochemical study of 15 cases with PCR analysis for Merkel cell polyomavirus.

Merkel cell carcinoma with divergent differentiation: histopathological and immunohistochemical study of 15 cases with PCR analysis for Merkel cell polyomavirus.

Apr 2013


Dermatopathology Department, St John's Institute of Dermatology, St Thomas' Hospital, London, UK.



To report on 15 cases of Merkel cell carcinoma (MCC) with divergent differentiation, to characterize its clinicopathological spectrum and its relationship with Merkel cell polyomavirus (MCV).

METHODS AND RESULTS: Fifteen patients with a mean age of 81 years were included. Follow-up was available for 13 cases (range 12 days to 6 years; median 6 months). Recurrence, metastasis and mortality rates were 15.4%, 53.8% and 61.5%, respectively. All tumours showed the typical histological and immunohistochemical features of MCC, with at least one additional divergent component. Eight cases had a single aberrant component (squamous in six cases, follicular in one case, and porocarcinoma in one case), six cases had two aberrant components (squamous and sarcomatous in three cases, glandular and squamous in two cases, and sarcomatous and neuroblastic in one case), and one case had three aberrant components (glandular, squamous, and sarcomatous). All cases had dysplastic changes in the overlying epithelium, and four of 15 showed epidermotropism. PCR analysis for Merkel cell polyomavirus (MCV) gave negative results in all 12 cases tested.


Merkel cell carcinoma with divergent differentiation is a highly aggressive tumour that might be difficult to recognize, owing to its wide histological variability. Negativity for MCV suggests that the virus is not implicated in the development of this subtype of MCC.