Lymph nodes & spleen, nonlymphoma

Lymph nodes-inflammatory / reactive disorders

Dermatopathic lymphadenitis

Last author update: 1 December 2017
Last staff update: 30 January 2023 (update in progress)

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PubMed search: Dermatopathic lymphadenitis

Jayalakshmi Balakrishna, M.D.
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Cite this page: Balakrishna J, Sharabi A. Dermatopathic lymphadenitis. website. Accessed February 8th, 2023.
Definition / general
  • Type of paracortical hyperplasia, commonly occurring in lymph nodes draining areas with chronic skin irritation
Essential features
  • Paracortical expansion with nodular proliferation of interdigitating dendritic cells, Langerhans cells and histiocytes
  • Most often pigment in the histiocytic cytoplasm, including melanin and rarely iron
ICD coding
  • I88.9 - Nonspecific lymphadenitis, unspecified
  • Most (but not all) cases are associated with chronic exfoliative or eczematoid skin disease
  • Dermatopathic lymphadenitis can occur as a reaction to mycosis fungoides / Sézary syndrome
  • Men are affected twice as frequently as women
  • Axillary and inguinal lymph nodes are most commonly affected
  • Reaction to drainage of melanin and various skin antigens
  • Chronic skin irritation
Clinical features
  • Enlarged, firm, movable, nontender lymph nodes
  • Peripheral blood eosinophilia may be present
  • Associated with skin disease
  • Clinical presentation, biopsy and histopathology with immunohistochemistry
  • Early involvement by mycosis fungoides can be ruled out by testing for T cell clonality with PCR
  • Peripheral blood eosinophilia
Radiology description
  • Enlarged lymph nodes
Radiology images

Images hosted on other servers:

CT showing enlarged lymph nodes

Prognostic factors
  • Association with mycosis fungoides confers a poorer prognosis
Case reports
  • Treatment of the underlying skin irritation or mycosis fungoides (if present)
Clinical images

Images hosted on other servers:

Cervical lymphadenopathy

Elastic firm nodules

Gross description
  • Enlarged lymph nodes with firm tan to yellow cut surface
  • There may be brown pigmented areas
Microscopic (histologic) description
  • Preserved architecture and marked paracortical expansion with irregular nodular pale areas located adjacent to the subcapsular sinuses and capsule
  • Early stages also show hyperplastic follicles; in later stages follicles become compressed or atrophic
  • High power shows the pale areas composed of interdigitating dendritic cells and Langerhans cells admixed with small lymphocytes, plasma cells, eosinophils and histiocytes
    • The histiocytes may be foamy or may contain brown pigment in their cytoplasm
    • Pigment is commonly melanin but can be hemosiderin
  • Medulla may show plasmacytosis and dilated sinuses with histiocytes, plasma cells and eosinophils
Microscopic (histologic) images

Case #396

H&E images





AFIP images

Dermatopathic lymphadenopathy

In a patient with mycosis fungoides

Contributed by Mark R. Wick, M.D.

Various images

Cytology description
  • Polymorphous population of small and large lymphocytes admixed with pigment laden macrophages, immunoblasts, dendritic cells, monocytoid cells, eosinophils and plasma cells
Cytology images

Images hosted on other servers:

DLN showing histiocytes and eosinophil

Positive stains
Electron microscopy description
  • Interdigitating dendritic cells predominate over Langerhans cells and are differentiated from the latter by: more abundant hyperplastic smooth endoplasmic reticulum, lipid droplets and fibrogranular bodies; more prominent tubulovesicular complexes and melanin granules; lack of Birbeck granules which are characteristic of Langerhans cells
Molecular / cytogenetics description
  • Polyclonal population of T cells
  • Clonal T cell population favors early involvement by mycosis fungoides
Differential diagnosis
  • Classic Hodgkin lymphoma: lacks proliferation of Langerhans cells and interdigitating dendritic cells and characteristically contain Hodgkin / Reed-Sternberg cells
  • Mycosis fungoides / Sézary syndrome: aberrant T cell immunophenotype and presence of T cell clone
  • Toxoplasma lymphadenitis: epithelioid histiocytes, no interdigitating dendritic cells, no Langerhans cells proliferation
  • Viral lymphadenitis: paracortical expansion is a common feature; can be differentiated by the lack of pale staining nodular proliferation of interdigitating dendritic cells and Langerhans cells and viral serology assays
Board review style question #1
Dermatopathic lymphadenitis can be a difficult to distinguish from early lymph node involvement by mycosis fungoides / Sézary syndrome. What is a reliable feature to differentiate the two?

  1. Extensive lymphadenopathy
  2. Paracortical expansion with a polymorphous lymphohistiocytic infiltrate
  3. Presence of skin lesions
  4. Presence of T cell clone
Board review style answer #1
D. Presence of T cell clone: presence of T cell clone identified by molecular methods is the best way to differentiate dermatopathic lymphadenitis from early lymph node involvement by mycosis fungoides / Sézary syndrome.

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