B-cell pseudolymphoma

    Article Contributors: 
    Sean Klepper M.D.
    Stephen Lyle, M.D., ...

    Also known as: cutaneous B-cell lymphoid hyperplasia, lymphadenosis benigna cutis, lymphocytoma cutis, pseudolymphoma of Spiegler-Fendt

    Clinical Features:

    • Reactive proliferation of B-cells
    • May be secondary to a variety of immune provocations, such as insect bites, drugs, vaccinations, tattoos and infection with Borrelia burgdorferi.
    • Common sites are the face, nipple and scrotum.
    • Presents as a solitary, smooth, red to brown nodule.

    Histologic Features:

    • Well-circumscribed nodular collections of predominantly small mature lymphocytes within the dermis and sometimes subcutis
    • The nodules are frequently more densely packed within the upper dermis than the lower dermis ("top heavy").
    • Germinal centers are frequently present.
    • Important in the differential diagnosis with lymphoma is the admixture of smaller numbers of other cell types within the lymphoid collections: eosinophils, plasma cells and histiocytes.
    • The epidermis and adnexae are uninvolved, in contrast to lymphoma.
    • Mitotic figures are rare, except in germinal centers.
    • The B-cells stain for the usual B-cell markers (CD20, CD19. CD79a) and are polytypic for immunoglobulin light chains (kappa and lambda).  They are usually surrounded by numerous CD3+ T-cells.


    Cases associated with this book:

  • B-cell pseudolymphoma
    Author: Stephen Lyle, M.D., Ph.D.

    Conference: DermatopathologyConsultations.com Teaching Collection