Lymphoma and plasma cell neoplasms
B cell lymphoma subtypes
Primary effusion lymphoma (PEL)

Topic Completed: 1 March 2011

Revised: 6 February 2019

Copyright: 2001-2018,, Inc.

PubMed Search: primary effusion lymphoma

Nikhil Sangle, M.D.
Page views in 2018: 2,195
Page views in 2019 to date: 1,514
Cite this page: Sangle N. Primary effusion lymphoma (PEL). website. Accessed August 24th, 2019.
Definition / general
  • Rare type of diffuse large B cell lymphoma with lymphomatous effusions in pleural, pericardial and abdominal cavities but no tumor mass
  • Also called body cavity lymphoma
Clinical features
  • Only one body cavity typically involved
  • Strongly associated with HHV8 and advanced HIV; usually EBV+
  • Also occurs in non immunosuppressed patients, often elderly
  • Rarely, extracavitary tumors with features of PEL are seen in GI tract, skin, lung, CNS and lymph nodes
  • Survival usually only months
  • Solid variant: very rare; affects GI tract, skin, lung, cerebrum; rarely nodal (Hum Pathol 2002;33:846); may represent a heterogeneous group of disorders
Case reports
Microscopic (histologic) description
  • Immunoblastic cells with abundant basophilic cytoplasm, round nucleus, single prominent nucleoli, perinuclear halo, variable nuclear pleomorphism with binucleated cells
  • Occasional large Reed-Sternberg like and anaplastic cells
  • Rarely is solid with plasmablastic features
  • Solid variant: large pleomorphic cells; nodal case resembled anaplastic large cell lymphoma
Microscopic (histologic) images

Images hosted on other servers:

68 year old HIV- but HHV8+ patient

70 year old man with HHV8+, EBV+ pleural effusions

87 year old HIV- but HHV8+ man with T cell variant

Positive stains
Negative stains
Molecular / cytogenetics description
  • Often required for diagnosis since negative for B cell stains
  • Clonal rearrangements and somatic mutations of Ig heavy chain
  • Clonal Epstein Barr virus and HHV8 genetic sequences
  • Also gain of sequences in chromosomes 12 and X (Arch Pathol Lab Med 2000;124:824)
Molecular / cytogenetics images

Images hosted on other servers:

PCR for HHV8 and EBV

T cell variant: PCR for T cell receptor; PCR for HHV8

Differential diagnosis
Additional references
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