Neuroma



Neuroma


Thomas Mentzel, MD









Solitary circumscribed neuroma (“palisaded encapsulated neuroma”) represents a well-circumscribed, partly encapsulated, dermal, neural neoplasm.






Solitary circumscribed neuroma is composed of S100 positive Schwann cells. Often preexisting peripheral nerves image are seen on the base of these lesions.


TERMINOLOGY


Definitions



  • Represents proliferation of peripheral nerve fibers in which ratio of axons to Schwann cell fascicles approaches 1:1



    • Solitary circumscribed neuroma (“palisaded encapsulated neuroma”) represents spontaneous proliferation of peripheral nerve fibers


    • Multiple mucosal neuromas associated with multiple endocrine neoplasia syndrome (type 2B) represent rare autosomal dominant condition


    • Traumatic neuroma represents post-traumatic proliferation of peripheral nerve fibers


    • Morton neuroma represents degenerative neural change with reactive fibrosis on the foot


    • Pacinian neuroma represents painful hyperplasia of pacinian bodies on finger


    • Epithelial sheath neuroma represents proliferation of enlarged dermal nerves ensheathed by squamous epithelium


ETIOLOGY/PATHOGENESIS


Developmental Anomaly



  • Multiple mucosal neuromas in multiple endocrine neoplasia syndrome



    • Represents rare autosomal dominant condition


    • Also includes medullary carcinoma of thyroid, pheochromocytoma, and somatic abnormalities


    • Mucosal neuromas have been rarely reported without any other systemic features of the syndrome


Environmental Exposure



  • Traumatic neuroma



    • Amputation neuroma represents painful, reactive proliferation of nerve fibers after amputation


    • Supernumerary digit represents proliferation of nonencapsulated nerve fibers after intrauterine or perinatal amputation of supernumerary digits


    • Lesion on penis may occur after circumcision


  • Morton neuroma



    • Degenerative damage of peripheral nerves


CLINICAL ISSUES


Epidemiology



  • Age



    • Solitary circumscribed neuroma is most common in 5th and 7th decades


  • Gender



    • Solitary circumscribed neuroma occurs in equal ratio in both genders


Site



  • Solitary circumscribed neuroma



    • Majority (90%) located on face


    • Rare in other anatomic locations


    • Mucosal involvement has been reported rarely


  • Morton neuroma



    • Usually in distal parts of peripheral nerves of 3rd and 4th os metatarsale


  • Pacinian neuroma



    • Usually on fingers


Presentation



  • Painful or painless mass


  • Slow growing


Treatment



  • Surgical approaches



    • Simple excision is curative


Prognosis



  • Biologically benign lesions



MACROSCOPIC FEATURES


General Features



  • Raised dermal lesions

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Neuroma

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