Cellular neurothekoma

    Also known as: immature nerve sheath myxoma

    Clinical Features:

    • Benign tumor of controversial histogenesis
    • Most often seen in young adults, with a female predominance
    • May affect any area of the body, but most common on the head and neck
    • Firm pink to red-brown papule or nodule
    • May recur if incompletely excised

    Histologic Features:

    • Ill-defined lesion filling the dermis and sometimes extending into the subcutis
    • Fascicular, nodular, nested or plexiform pattern
    • Composed of epithelioid to spindled cells with abundant eosinophilic cytoplasm and ovoid nuclei with prominent nucleoli
    • Numerous mitoses can sometimes be seen.
    • Foci of significant atypia are sometimes present.
    • In contrast to classic neurothekeoma, myxoid change is not a prominent feature.
    • Stromal changes can include chronic inflammation, fibrosis and hyalinization.
    • The epidermis can on occasion show melanocytic hyperplasia.
    • Immunohistochemistry of is of limited utility.  The tumor is negative or only weakly positive for S-100, Leu-7 (CD57), type IV collagen and EMA.  Some cases are positive for NSE, MSA or CD34.  The only universally positive immunohistochemical stain is vimentin.

    Cases associated with this book:

  • Cellular neurothekeoma
    Author: Stephen Lyle, M.D., Ph.D.

    Conference: DermatopathologyConsultations.com Teaching Collection