Background: Rudimentary polydactyly histologically reveals a marked neural proliferation in the dermis and a large number of Meissner corpuscles in the dermal papillae. Objective: Our study was performed to determine whether this neural proliferation is related to Merkel cells. Method: Using an antibody to cytokeratin 20, we examined the number and distribution of Merkel cells in 5 cases of rudimentary polydactyly, including an immature case without Meissner corpuscles. Results: Only the case without Meissner corpuscles had a markedly large number of Merkel cells and some dermal Merkel cells. Conclusion: The normal number of Merkel cells in the mature cases suggests that abundant Merkel cells may appear at first and disappear after the development of neural proliferation. Merkel cells may be associated with the generation of cutaneous nerve plexus and nerve endings in the upper dermis, and possibly with the development of Meissner corpuscles, at the early stage of rudimentary polydactyly.

Keywords:
Rudimentary polydactyly, Merkel cells, Meissner corpuscles, Neural proliferation, Cytokeratin 20
1.
Shapiro L, Juhlin EA, Brownstein MH: Rudimentary polydactyly. Arch Dermatol 1973;108:223–225.
2.
Chung J, Nam IW, Ahn SK, Lee SH, Kim JG, Sung YO: Rudimentary polydactyly. J Dermatol 1994;21:54–55.
3.
Scott SA, Cooper E, Diamond J: Merkel cells as targets of the mechanosensory nerves in salamander skin. Proc R Soc Lond B 1981;211:455–470.
4.
Pasche F, Mérot Y, Carraux P, Saurat JH: Relationship between Merkel cells and nerve endings during embryogenesis in the mouse epidermis. J Invest Dermatol 1990;95:247–251.
5.
Narisawa Y, Hashimoto K, Nihei Y, Pietruk T: Biological significance of dermal Merkel cells in development of cutaneous nerves in human fetal skin. J Histochem Cytochem 1992;40:65–71.
6.
Suzuki H, Matsuoka S: Rudimentary polydactyly (cutaneous neuroma): Case report with ultrastructural study. J Cutan Pathol 1981;8:299–307.
7.
Moll I, Kuhn C, Moll R: Cytokeratin 20 is a general marker of cutaneous Merkel cells while certain neuronal proteins are absent. J Invest Dermatol 1995;104:910–915.
8.
Hare PJ: Rudimentary polydactyly. Br J Dermatol 1954;66:402–408.
9.
Murphy GF: Histology of the skin; in Elder D, Elenitsas R, Jaworsky C, Johnson B Jr (eds): Lever’s Histopathology of the Skin, ed 8. Lippincott-Raven, Philadelphia, 1997, p 34.
10.
Ide C: Development of Meissner corpuscle of mouse toe pad. Anat Rec 1977;188:49–68.
11.
Moll R, Moll I, Werner WF: Identification of Merkel cells in human skin by specific cytokeratin antibodies: Change of cell density and distribution in fetal and adult plantar epidermis. Differentiation 1984;28:136–154.
© 2001 S. Karger AG, Basel
2001
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.