Lymph nodes & spleen, nonlymphoma


Common nonspecific abnormal features

Last author update: 1 October 2012
Last staff update: 21 December 2022

Copyright: 2012-2023,, Inc.

PubMed Search: Abnormal features spleen

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Cite this page: Mansouri J, Lynch D. Common nonspecific abnormal features. website. Accessed September 27th, 2023.
Foamy macrophages
Definition / general
  • Increased foamy histiocytes / macrophages, typically in the red pulp

Essential features
  • Associated with a wide variety of conditions both benign and malignant
  • Conditions with high cell turnover may produce foamy histiocytes
  • Diagnosis typically requires clinicopathologic correlation

  • Ceroid histiocytosis - histiocytes filled with phospholipids; not specific to a single disease entity

Case reports

Microscopic (histologic) description
  • Red pulp expanded by histiocytes with abundant foamy cytoplasm
  • Histiocytes scattered without forming a discrete mass
  • May have basophilic cytoplasm from ingestion of platelets in idiopathic thrombocytopenic purpura (ITP)
  • Finely fibrillary cytoplasm suggests underlying storage disease
  • White pulp is normal in size

Microscopic (histologic) images

Contributed by David Lynch, M.D.
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Foamy histiocytes

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Positive stains

Negative stains

Differential diagnosis

Additional references
Follicular hyperplasia
Definition / general
  • Also called reactive follicular hyperplasia
  • Focal or diffuse
  • Normal in children
  • In adults, due to systemic infection (malaria, measles, typhoid fever, virus, other), immune mediate disorders (hemolytic anemia, immune thrombocytopenic purpura, rheumatoid arthritis)
  • Often associated with congestion and plasmacytic proliferation
  • Associated with hypersplenism in Zaire, Nigeria and New Guinea, where spleens also show extramedullary hematopoiesis and marked sinusoidal dilation; may be related to malaria
  • Note: graft rejection and AIDS are associated with reactive nonfollicular hyperplasia, which may resemble lymphoma but has heterogeneous lymphocytic population without atypia and without clonality
  • Felty syndrome (rheumatoid arthritis): no granulocytic phagocytosis but expansion of red pulp cords and sinuses with macrophages

Gross description
  • May have enlarged spleen with multiple small, pale tan nodules or solitary large nodules resembling lymphoma (Am J Surg Pathol 1983;7:373)

Microscopic (histologic) description
  • Resemble nodal reactive follicles, with mixed follicular center population and tingible body macrophages
  • Usually mature lymphocytes and plasma cells in red pulp
  • Also called dysplenism
  • Enlarged spleen leads to removal of cellular blood components (some or all), causing thrombocytopenia, neutropenia, hemolytic anemia or pancytopenia
  • Due to disorders (congestive splenomegaly, Gaucher disease, hamartoma, hemangioma, Langerhans cell histiocytosis, leukemia / lymphoma, other conditions diffusely involving red pulp) causing widening of splenic cords with increase in macrophages or connective tissue, causing premature destruction of normal blood components
  • Reactive follicular hyperplasia of white pulp may be present in hypersplenism associated with cytopenias
  • Infectious causes include brucellosis, CMV, Echinococcus, histoplasmosis, infectious mononucleosis, leishmaniasis, malaria, schistosomiasis, syphilis, toxoplasmosis, trypanosomiasis, tuberculosis, typhoid
  • May be due to abnormal cellular blood components (hereditary spherocytosis)
Definition / general
  • Due to thrombosis of splenic vein, usually secondary to cardiac emboli
  • Also associated with granulomatosis with polyangiitis (Wegener) (may cause splenic rupture), massive splenomegaly, idiopathic

Gross description
  • Wedge shaped white-gray infarct involving capsule; infarcts heal as large, depressed scars
  • Thick fibrous plaques coating splenic surface
  • Incidental finding at autopsy or associated with portal hypertension
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