Lymphoma and plasma cell neoplasms
T / NK cell disorders
Primary cutaneous CD4+ small / medium T cell lymphoma

Author: Dragos Luca, M.D. (see Authors page)

Revised: 27 March 2017, last major update August 2011

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PubMed search: Primary cutaneous CD4+ small / medium T cell lymphoma

Cite this page: Primary cutaneous CD4+ small / medium T cell lymphoma. PathologyOutlines.com website. http://pathologyoutlines.com/topic/lymphomanonBcutaneouscd4.html. Accessed November 19th, 2017.
Definition / general
Terminology
  • Cutaneous nodular proliferation of pleomorphic T-lymphocytes of undetermined significance
Epidemiology
  • Rare, 2% of all cutaneous T cell lymphomas
Sites
  • Solitary plaque or nodule on face, neck, upper trunk
  • Lower extremity involvement is rare
Clinical features
  • Usually asymptomatic; only clinical feature is a solitary skin lesion
  • Rarely large tumors or multiple skin lesions
Case reports
Treatment
Treatment and prognosis:
  • Favorable prognosis, 80% 5 year survival
  • Solitary skin lesions have an excellent prognosis (surgical excision or radiotherapy), multiple / large lesions may be more aggressive
Postulated normal counterpart
  • Skin homing CD4+ T cell
Gross description
  • Solitary plaque or nodule (more favorable) or multiple or large lesions (more aggressive)
Gross images

Images hosted on other servers:

Various images

Microscopic (histologic) description
  • Dense, diffuse or nodular dermal infiltrate with tendency to subcutaneous involvement
  • May have focal epidermotropism but if more than that, consider mycosis fungoides
  • Predominantly small / medium sized pleomorphic T cells sometimes with a small proportion (< 30%) of large pleomorphic cells
  • May have admixed reactive lymphocytes, histiocytes, eosinophils, plasma cells
Microscopic (histologic) images

Images hosted on other servers:

Various images

Positive stains
Negative stains
  • CD8, CD30, cytotoxic markers, loss of a pan-T cell marker, EBV
Molecular / cytogenetics description
  • Clonal rearrangements of the TCR genes
  • No specific cytogenetic abnormality
Molecular / cytogenetics images

Images hosted on other servers:

Various images

Differential diagnosis
  • Reactive lymphoid infiltrate of the skin: also called pseudolymphoma or cutaneous lymphoid hyperplasia; no clonal TCR gene rearrangements, no loss of a pan-T cell marker