Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Supernumerary Digit Workup

  • Author: Luke Lennox, MD; Chief Editor: Dirk M Elston, MD  more...
 
Updated: Mar 29, 2016
 

Imaging Studies

Prenatal ultrasound

Fetal finger buds can be seen using transvaginal ultrasound as early as 9 weeks and reliably by 13 weeks of pregnancy. Once polydactyly is established, a thorough ultrasound evaluation, especially of the heart, nervous system, limbs, and kidneys, to identify an associated syndrome (eg, Meckel-Gruber syndrome, trisomy 13) should be performed. Follow-up ultrasound between 17 and 34 weeks with biometric profile is recommended to establish the diagnosis of isolated polydactyly.[14, 15]

Radiographs

Radiographs of the affected limb are recommended to show whether the rudimentary digit contains skeletal elements. The degree of deviation of the digit and the size of the articulating metacarpal or metatarsal also may be helpful in surgical planning.

Next

Histologic Findings

Rudimentary polydactyly, which may be a type of congenital traumatic neuroma, shows hyperkeratosis and acanthosis overlying many nerve bundles in the dermis. It may appear as a papule on the base of the ulnar side of the little finger. Abundant Merkel cells may appear at first and then disappear after the development of these nerve bundles, which form Meissner corpuscles in the dermal papillae and stain positively with S-100 protein.[16]

See the histology slides below.

Supernumerary digit, no magnification.Supernumerary digit, no magnification.
Twenty-eight-day-old supernumerary digit, connectiTwenty-eight-day-old supernumerary digit, connective tissue and epidermis (40x).
Twenty-eight-day-old supernumerary digit, nerve buTwenty-eight-day-old supernumerary digit, nerve bundle base (40x).

 

Twenty-eight-day-old supernumerary digit, rudimentTwenty-eight-day-old supernumerary digit, rudimentary nail unit cartilage (2x).
Previous
 
 
Contributor Information and Disclosures
Author

Luke Lennox, MD Resident Physician, Department of Medicine, University of Buffalo, State University of New York School of Medicine and Biomedical Sciences

Disclosure: Nothing to disclose.

Coauthor(s)

Thomas N Helm, MD Clinical Professor of Dermatology and Pathology, University of Buffalo, State University of New York School of Medicine and Biomedical Sciences; Director, Buffalo Medical Group Dermatopathology Laboratory

Thomas N Helm, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Society for Dermatologic Surgery, American Society of Dermatopathology

Disclosure: Nothing to disclose.

Specialty Editor Board

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Texas Medical Association, Association of Military Dermatologists, Texas Dermatological Society

Disclosure: Nothing to disclose.

Robert A Schwartz, MD, MPH Professor and Head of Dermatology, Professor of Pathology, Pediatrics, Medicine, and Preventive Medicine and Community Health, Rutgers New Jersey Medical School; Visiting Professor, Rutgers University School of Public Affairs and Administration

Robert A Schwartz, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, New York Academy of Medicine, American Academy of Dermatology, American College of Physicians, Sigma Xi

Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD Professor and Chairman, Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina College of Medicine

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

Additional Contributors

Albert C Yan, MD Section Chief, Associate Professor, Department of Pediatrics, Section of Dermatology, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine

Albert C Yan, MD is a member of the following medical societies: American Academy of Dermatology, Society for Investigative Dermatology, Society for Pediatric Dermatology, American Academy of Pediatrics

Disclosure: Nothing to disclose.

Carter G Abel, MD Clinical Assistant Attending, Department of Dermatology, New York Presbyterian Hospital

Carter G Abel, MD is a member of the following medical societies: American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery, Medical Society of New Jersey

Disclosure: Nothing to disclose.

Denise M McCarthy, MD Associate Professor, Department of Radiology, Morristown Memorial Hospital

Denise M McCarthy, MD is a member of the following medical societies: American Association for Women Radiologists, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America

Disclosure: Nothing to disclose.

References
  1. Hosalkar HS, Shah H, Gujar P, Kulkarni AD. Crossed polydactyly. J Postgrad Med. 1999 Jul-Sep. 45(3):90-2. [Medline].

  2. Wattanarat O, Kantaputra PN. Preaxial polydactyly associated with a MSX1 mutation and report of two novel mutations. Am J Med Genet A. 2015 Oct 13. [Medline].

  3. Bouldin CM, Harfe BD. Aberrant FGF signaling, independent of ectopic hedgehog signaling, initiates preaxial polydactyly in Dorking chickens. Dev Biol. 2009 Oct 1. 334 (1):133-41. [Medline].

  4. Muragaki Y, Mundlos S, Upton J, Olsen BR. Altered growth and branching patterns in synpolydactyly caused by mutations in HOXD13. Science. 1996 Apr 26. 272(5261):548-51. [Medline].

  5. Finley WH, Gustavson KH, Hall TM, Hurst DC, Barganier CM, Wiedmeyer JA. Birth defects surveillance: Jefferson County, Alabama, and Uppsala County, Sweden. South Med J. 1994 Apr. 87(4):440-5. [Medline].

  6. Cohen MS. Thumb duplication. Hand Clin. 1998 Feb. 14(1):17-27. [Medline].

  7. Hung L, Cheng JC, Bundoc R, Leung P. Thumb duplication at the metacarpophalangeal joint. Management and a new classification. Clin Orthop Relat Res. 1996 Feb. 31-41. [Medline].

  8. Klaassen Z, Shoja MM, Tubbs RS, Loukas M. Supernumerary and absent limbs and digits of the lower limb: a review of the literature. Clin Anat. 2011 Jul. 24(5):570-5. [Medline].

  9. Temtamy SA, McKusick VA. The genetics of hand malformations. Birth Defects Orig Artic Ser. 1978. 14(3):i-xviii, 1-619. [Medline].

  10. Malik S, Grzeschik KH. Synpolydactyly: clinical and molecular advances. Clin Genet. 2008 Feb. 73(2):113-20. [Medline].

  11. Tian F, Tian LJ, Zhao W, Li XC, Li B, Ji XL. Plastic repair for a case with synpolydactyly. Arch Orthop Trauma Surg. 2011 Jun. 131(6):869-73. [Medline].

  12. Castilla EE, Lugarinho R, da Graça Dutra M, Salgado LJ. Associated anomalies in individuals with polydactyly. Am J Med Genet. 1998 Dec 28. 80(5):459-65. [Medline].

  13. Jafari D, Sharifi B. A variant of mirror hand. A case report. J Bone Joint Surg Br. 2005 Jan. 87(1):108-10. [Medline].

  14. Bromley B, Shipp TD, Benacerraf B. Isolated polydactyly: prenatal diagnosis and perinatal outcome. Prenat Diagn. 2000 Nov. 20(11):905-8. [Medline].

  15. Zimmer EZ, Bronshtein M. Fetal polydactyly diagnosis during early pregnancy: clinical applications. Am J Obstet Gynecol. 2000 Sep. 183(3):755-8. [Medline].

  16. Ban M, Kitajima Y. The number and distribution of Merkel cells in rudimentary polydactyly. Dermatology. 2001. 202(1):31-4. [Medline].

  17. Eskandari MM, Oztuna V, Demirkan F. Late psychosocial effects of congenital hand anomaly. Hand Surg. 2004 Dec. 9(2):257-9. [Medline].

  18. Morley SE, Smith PJ. Polydactyly of the feet in children: suggestions for surgical management. Br J Plast Surg. 2001 Jan. 54(1):34-8. [Medline].

  19. Park GH, Jung ST, Chung JY, Park HW, Lee DH. Toe component excision in postaxial polydactyly of the foot. Foot Ankle Int. 2013 Apr. 34(4):563-7. [Medline].

  20. Dijkman R, Selles R, van Rosmalen J, Hülsemann W, Mann M, Habenicht R, et al. A clinically weighted approach to outcome assessment in radial polydactyly. J Hand Surg Eur Vol. 2015 Aug 28. [Medline].

  21. Hartzell TL, Taylor H. Traumatic amputation of a supernumerary digit: a 16-year-old boy's perspective of suture ligation. Pediatr Dermatol. 2009 Jan-Feb. 26 (1):100-2. [Medline].

  22. Katz K, Linder N. Postaxial type B polydactyly treated by excision in the neonatal nursery. J Pediatr Orthop. 2011 Jun. 31 (4):448-9. [Medline].

Previous
Next
 
Twenty-eight-day-old supernumerary digit, rudimentary nail unit cartilage (2x).
Twenty-eight-day-old supernumerary digit, nerve bundle base (40x).
Twenty-eight-day-old supernumerary digit, connective tissue and epidermis (40x).
Supernumerary digit, no magnification.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.