Reactive Follicular Hyperplasia

Reactive Follicular Hyperplasia

C. Cameron Yin, MD, PhD

A hyperplastic lymphoid follicle is seen with a central, prominent germinal center and a peripheral, sharply demarcated mantle zone.

A reactive germinal center is composed of a mixed population of centrocytes, centroblasts, follicular dendritic cells, and tingible-body macrophages.



  • Reactive follicular hyperplasia (RFH)


  • Follicular hyperplasia


  • Benign, reversible process characterized by marked proliferation of hyperplastic lymphoid follicles

    • Hyperplastic follicles have prominent germinal centers (so-called secondary follicles)

    • Characteristic of humoral immune reaction involving stimulation and proliferation of B cells

    • Usually involves lymph nodes but can affect extranodal organs


Environmental Exposure

  • Variety of drugs, chemicals, and environmental pollutants can cause RFH

Infectious Agents

  • Most common cause of RFH is bacterial infection

    • Fungi, parasites, and viruses also can cause RFH, either pure or as part of mixed reactive pattern


  • In many cases, etiology of RFH cannot be identified



  • Patients typically present with enlarged lymph nodes, either localized or widespread

    • Systemic symptoms, such as fever, fatigue, and weight loss, may be present

    • Laboratory abnormalities, such as leukocytosis, neutrophilia, or lymphocytosis, are common with infections and may be present

  • Lymph node size is important

    • Small, shotty lymph nodes in asymptomatic patients are within normal limits

    • Lymph nodes ≥ 1 cm in diameter are abnormal

  • Painful lymph nodes are more often related to inflammation or hemorrhage

  • Age and duration are important in identifying etiology

  • Location and consistency can suggest most likely etiologic agent

    • Location, as related to likely causes of lymphadenopathy

      • Cervical: Infectious mononucleosis

      • Posterior cervical: Toxoplasmosis

      • Parotid, submaxillary, epitrochlear: HIV infection

      • Cervical and axillary: Cat scratch disease

      • Inguinal: Sexually transmitted diseases

      • Supraclavicular: Often associated with malignant diseases, especially in older patients

    • Consistency, as related to likely causes of lymphadenopathy

      • Soft: Inflammatory

      • Fluctuant: Suppurative infection (often bacterial or fungal)

      • Matted: Tuberculosis, lymphogranuloma venereum, cancer

      • Firm to hard: Malignancy, including lymphoma or metastatic carcinoma


  • Localized lymph node enlargement in absence of other symptoms requires follow-up for 3-4 weeks

    • If lymphadenopathy does not resolve, additional investigation is likely needed

  • Generalized lymphadenopathy usually requires immediate investigation for etiology


  • Benign, reversible process with no impact on patient survival

    • Can be associated with other diseases such as autoimmune disease or malignancy


Histologic Features

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Reactive Follicular Hyperplasia

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