eMedicine Specialties > Physical Medicine and Rehabilitation > Lower Limb Musculoskeletal Conditions

Morton Neuroma: Differential Diagnoses & Workup

Author: Kevin Berry, MD, Resident Physician, Physical Medicine and Rehabilitation Department, University of Colorado Hospital
Coauthor(s): Peter Gonzalez, MD, Assistant Professor, Department of Physical Medicine and Rehabilitation, University of Colorado School of Medicine; Richard G Bowman II, MD, Rehabilitation and Electrodiagnostic Director, Physical Medicine and Rehabilitation, Pain Management, The Center for Pain Relief
Contributor Information and Disclosures

Updated: May 26, 2009

Differential Diagnoses

Other Problems to Be Considered

Stress fracture of the neck of the metatarsal
Rheumatoid arthritis and other systemic arthritis conditions
Hammer toe
Metatarsalgia (plantar tenderness over the metatarsal head)
Neoplasms
Metatarsal head osteonecrosis
Freiburg osteochondrosis
Ganglion cysts
Intermetatarsal bursal fluid collections
True neuromas

Workup

Laboratory Studies

  • No laboratory studies are indicated for the diagnosis of Morton's neuroma.

Imaging Studies

  • Results of plain films are normal in Morton's neuroma.
  • Ultrasonography, although not often used, may detect Morton's neuroma, but it has questionable reliability.4
  • Computed tomography (CT) scanning has been used but may not be as sensitive as magnetic resonance imaging (MRI).
    • MRI, while not needed in most cases for establishing diagnosis of Morton's neuroma, has been studied widely.5
    • Sensitivity of 87% and specificity as high as 100% have been reported. Asymptomatic neuromas may occur and confound accurate diagnosis.
  • Indications exist that Morton's neuromas smaller than 5 mm in diameter may not be significant clinically and that other diagnoses may be excluded carefully before such a small lesion is diagnosed as a symptomatic Morton's neuroma. Imaging with T1 weighting in a coronal plane is recommended for best visualization. In addition, on T2 imaging, the low signal of a Morton's neuroma may help to differentiate it from a true neuroma, ganglion cyst, or intermetatarsal bursal fluid collection.
  • Contrast enhancement usually is demonstrated with Morton's neuromas.

Other Tests

  • Electromyography and nerve conduction study (EMG/NCS) of Morton's neuroma are not used often because of the technical difficulty in performing the them; needle stimulation of the common digital nerve and pickup on the adjacent toe or toes, which may be of short distance, is required. Surface stimulation results most often in volume conduction through the skin to the pickups because of the short distance involved and the large amount of stimulation needed to penetrate the deep tissue separating the nerve from the skin surface.

Procedures

  • Temporary elimination of pain and numbness in the associated webspace by a common digital nerve block with an anesthetic agent supports a diagnosis of Morton's neuroma. If numbness of the associated webspace occurs but no decrease in pain is noted, other diagnoses should be considered.

Histologic Findings

Tissue biopsy is neither needed nor recommended for Morton's neuroma.

More on Morton Neuroma

Overview: Morton Neuroma
Differential Diagnoses & Workup: Morton Neuroma
Treatment & Medication: Morton Neuroma
Follow-up: Morton Neuroma
Multimedia: Morton Neuroma
References
Further Reading
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References

  1. Morton TG. Peculiar painful affection of fourth metatarsophalangeal articulation. Am J Med Sci. 1876;71:37.

  2. Kim JY, Choi JH, Park J, et al. An anatomical study of Morton's interdigital neuroma: the relationship between the occurring site and the deep transverse metatarsal ligament (DTML). Foot Ankle Int. Sep 2007;28(9):1007-10. [Medline].

  3. O'Connor FG, Wilder RP, Nirschl R. Foot Injuries in the Runner. In:Textbook of Running Medicine. New York: McGraw-Hill; 2001;258-260.

  4. Lee MJ, Kim S, Huh YM, Song HT, Lee SA, Lee JW, et al. Morton neuroma: evaluated with ultrasonography and MR imaging. Korean J Radiol. Mar-Apr 2007;8(2):148-55. [Medline].

  5. Zanetti M, Weishaupt D. MR imaging of the forefoot: Morton neuroma and differential diagnoses. Semin Musculoskelet Radiol. Sep 2005;9(3):175-86.

  6. Akermark C, Saartok T, Zuber Z. A prospective 2-year follow-up study of plantar incisions in the treatment of primary intermetatarsal neuromas (Morton's neuroma). Foot Ankle Surg. 2008;14(2):67-73. [Medline].

  7. Monacelli G, Cascioli I, Prezzemolo G, Spagnoli A, Irace S. [Surgical treatment of Morton's neuroma: our experience and literature review]. Clin Ter. May-Jun 2008;159(3):165-7. [Medline].

  8. Valente M, Crucil M, Alecci V. Operative treatment of interdigital Morton's neuroma. Chir Organi Mov. May 2008;92(1):39-43. [Medline].

  9. Villas C, Florez B, Alfonso M. Neurectomy versus neurolysis for Morton's neuroma. Foot Ankle Int. Jun 2008;29(6):578-80. [Medline].

  10. Title CI, Schon LC. Morton neuroma: primary and secondary neurectomy. J Am Acad Orthop Surg. Sep 2008;16(9):550-7. [Medline].

  11. Markovic M, Crichton K, Read JW, et al. Effectiveness of ultrasound-guided corticosteroid injection in the treatment of Morton's neuroma. Foot Ankle Int. May 2008;29(5):483-7. [Medline].

  12. Betts LO. Morton's Metatarsalgia. Med J Aust. 1940;1:514.

  13. Clanton TO, Butler JE, Eggert A. Injuries to the metatarsophalangeal joints in athletes. Foot Ankle. Dec 1986;7(3):162-76. [Medline].

  14. Cyriax J. Diagnosis of soft tissue lesions.In: Textbook of Orthopaedic Medicine. 8th ed. Philadelphia, Pa:. The Curtis Center;1982.

  15. Guiloff RJ. Carbamazepine in Morton''s neuralgia. Br Med J. Oct 13 1979;2(6195):904. [Medline].

  16. Jahss MH, Kummer F. Non-inflammatory synovitis of the second metatarsophalangeal joint and its surgical management. Paper read at: 16th Annual Meeting of American Orthopaedic Foot Ankle Society, New Orleans, La. February 1986.

  17. Logan PM, Janzen DL, O''Connell JX, et al. Magnetic resonance imaging and histopathologic appearances of benign soft-tissue masses of the foot. Can Assoc Radiol J. Feb 1996;47(1):36-43. [Medline].

  18. Mizel MS, Miller RA, Scioli MW. Orthopaedic knowledge update. In: Foot and Ankle. Rosemont, Ill:. American Academy of Orthopaedic Surgeons;1998.

  19. Snyder RK. In: Essentials of Musculoskeletal Care. Rosemont, Ill:. American Academy of Orthopedic Surgeons;1997.

  20. Terk MR, Kwong PK, Suthar M, et al. Morton neuroma: evaluation with MR imaging performed with contrast enhancement and fat suppression. Radiology. Oct 1993;189(1):239-41. [Medline].

  21. Vazquez-Abad D, Tian L, Monteon V, et al. CRI-EM is a human idiotype highly specific for scleroderma. Ann N Y Acad Sci. Apr 5 1997;815:512-5. [Medline].

  22. Wu KK. Morton neuroma and metatarsalgia. Curr Opin Rheumatol. Mar 2000;12(2):131-42. [Medline].

  23. Yocum LA. In: Clinics in Sports Medicine. Vol 7. Philadelphia, Pa:. WB Saunders Co;1988.

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Keywords

Morton neuroma, Morton's neuroma, neuroma, metatarsal, foot surgery, foot pain, feet pain, metatarsals, neuroma surgery, foot neuroma, neuromas, neuroma treatment, metatarsalgia, plantar nerve, interdigital nerve, Morton's metatarsalgia, interdigital neuroma, plantar neuroma, Morton metatarsalgia

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Contributor Information and Disclosures

Author

Kevin Berry, MD, Resident Physician, Physical Medicine and Rehabilitation Department, University of Colorado Hospital
Kevin Berry, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, American Medical Association, American Medical Student Association/Foundation, and Illinois State Medical Society
Disclosure: Nothing to disclose.

Coauthor(s)

Peter Gonzalez, MD, Assistant Professor, Department of Physical Medicine and Rehabilitation, University of Colorado School of Medicine
Peter Gonzalez, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, American Association of Neuromuscular and Electrodiagnostic Medicine, American College of Sports Medicine, and Physiatric Association of Spine, Sports and Occupational Rehabilitation
Disclosure: Nothing to disclose.

Richard G Bowman II, MD, Rehabilitation and Electrodiagnostic Director, Physical Medicine and Rehabilitation, Pain Management, The Center for Pain Relief
Richard G Bowman II, MD is a member of the following medical societies: American Medical Association
Disclosure: Nothing to disclose.

Medical Editor

Robert J Kaplan, MD, James E Van Zandt VA Medical Center, Staff Physician, Department of Rehabilitation Medicine
Robert J Kaplan, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, Association of Academic Physiatrists, and Physiatric Association of Spine, Sports and Occupational Rehabilitation
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Michael T Andary, MD, MS, Residency Program Director, Professor, Department of Physical Medicine and Rehabilitation, Michigan State University College of Osteopathic Medicine
Michael T Andary, MD, MS is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, American Association of Neuromuscular and Electrodiagnostic Medicine, American Medical Association, and Association of Academic Physiatrists
Disclosure: allergan Honoraria Speaking and teaching; Pfizer Honoraria Speaking and teaching

CME Editor

Kelly L Allen, MD, Regional Medical Director, IMX-Medical Management Services
Disclosure: Nothing to disclose.

Chief Editor

Consuelo T Lorenzo, MD, Consulting Staff, Department of Physical Medicine and Rehabilitation, Alegent Health Care, Immanuel Rehabilitation Center
Consuelo T Lorenzo, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation
Disclosure: Nothing to disclose.

 
 
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