Florid Lymphoid Hyperplasia or Lymphoma-like Lesion of the Lower Genital Tract: A 35-Year Literature Review in View of the New WHO Classification.

Florid lymphoid hyperplasias of the lower female genital tract, also known as pseudolymphoma or lymphoma-like lesions, are benign lesions displaying histologic features which mimic aggressive B-cell lymphomas. Initially described by Young and colleagues in 1985, fewer than 100 cases have been published, making this lesion rather uncommon and subject to misdiagnoses. However, given that this entity has now been included in the World Health Organization's most recent classification, greater clarity would be beneficial for pathologists and physicians. Thus, our report aims to review these entities and provide all available data. We reviewed the available literature according to PRISMA guidelines. We found that lymphoma-like lesions, regardless of their localization, display numerous superficial lymphoid B cells admixed with a polymorphic small lymphocytic and plasmocytic background and, sometimes, superficial ulceration. Large lymphoid cells show prominent nucleoli and mitotic figures. Immunohistochemistry can usually exclude large cell lymphomas, such as high-grade follicular lymphoma and Burkitt lymphoma, when a starry sky pattern is found, as well as Hodgkin Lymphoma; however, the exclusion of diffuse large B-cell lymphoma or marginal zone lymphoma is more difficult. Explorations seeking infectious agents may show Epstein-Barr virus or, rarely, Borrelia burgdorferi involvement. Molecular study occasionally finds a monoclonal B-cell population, but without the subsequent follow-up which would otherwise be worrisome. Despite its somewhat aggressive histologic features, the benignity of this entity must be highlighted to avoid misdiagnosis and complications due to overtreating.