Epidermotropic Merkel cell carcinoma: A case series with histopathologic examination - 24/04/13
Abstract |
Background |
Merkel cell carcinoma (MCC), an aggressive malignancy that has been increasing in incidence, rarely presents with an epidermotropic pattern.
Objective |
We conducted an immunohistochemical evaluation of 6 previously unpublished cases of epidermotropic MCC, focusing particularly on the staining characteristics of epithelial membrane antigen and cytokeratin-20 in the hope of providing insight into the mechanism of epidermotropism in MCC.
Methods |
This study is a retrospective evaluation using light microscopy and immunohistochemistry.
Results |
Forty cases of MCC with pathology at Rhode Island Hospital and the Miriam Hospital in Providence, RI, from 1983 through 2009 were reviewed. Following exclusion criteria, 6 patients (5 men, 1 woman) with a mean age of 82.5 years (range, 72-92) demonstrated epidermotropism. Three of 6 patients had MCC of the eyelid. In cases 1, 3, and 6, the perinuclear dot pattern observed with cytokeratin-20 in the epidermotropic MCC cells was less pronounced than the pattern observed in the dermis, and in all 6 of the tumors, the epidermal staining pattern observed with epithelial membrane antigen was not more or less prominent than the staining observed in the dermis.
Limitations |
The small total number of cases of epidermotropic MCC is a limitation.
Conclusion |
The data presented reinforce the differential diagnosis of tumors with an epidermotropic growth pattern and the importance of immunohistochemical staining in the histologic workup of such tumors: squamous cell carcinoma in situ, melanoma, mycosis fungoides, eccrine porocarcinoma, sebaceous carcinoma of the eyelid, mammary and extramammary Paget disease, MCC, and epidermotropic metastases. It is notable that 3 of 6 identified tumors were located on the eyelid; further study of epidermotropic MCC may shed more light on this finding, either as an unusual coincidence or a finding with unexplained significance.
Le texte complet de cet article est disponible en PDF.Key words : eccrine porocarcinoma, epidermotropic metastases, epidermotropism, mammary and extramammary Paget disease, melanoma, Merkel cell carcinoma, mycosis fungoides, sebaceous carcinoma of the eyelid, squamous cell carcinoma in situ, staining characteristics
Abbreviations used : CK, EMA, MCC, MCPyV, TTF
Plan
Funding sources: None. |
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Conflicts of interest: None declared. |
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Reprints not available from the authors. |
Vol 62 - N° 3
P. 463-468 - mars 2010 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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