Lymphoma and plasma cell neoplasms
T / NK cell disorders
Primary cutaneous anaplastic large cell lymphoma (C-ALCL)

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 anaplastic large cell lymphoma [title] C-ALCL

Related topics: Primary cutaneous CD30+ T cell lymphoproliferative disorders

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Cite this page: Primary cutaneous anaplastic large cell lymphoma (C-ALCL). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphomanonBprimarycutTCALCL.html. Accessed May 23rd, 2019.
Definition / general
  • Cutaneous anaplastic large cell lymphoma is composed of large cells with an anaplastic, pleomorphic or immunoblastic cytomorphology that express the CD30 antigen by the majority (> 75%) of the tumor cells (WHO 2008)
Terminology
  • Also called regressing atypical histiocytosis (European Organisation for Research and Treatment of Cancer)
Epidemiology
  • Second most common type of cutaneous T cell lymphoma
  • Median age 60 years, M:F ratio 2 - 3:1, occasionally children
  • Common form of cutaneous T cell lymphoma in HIV+ individuals
Sites
  • Trunk, face, extremities, buttocks
Clinical features
  • Solitary or localized nodules / tumors, sometimes papules, often ulcerated
  • Multifocal lesions in 20% of cases
  • Extracutaneous dissemination (mainly regional lymph nodes) in 10% of cases
Prognostic factors
Treatment and prognosis:
  • Usually favorable prognosis (10 year disease related survival of 90%)
  • May show partial or complete spontaneous regression of skin lesions (10% - 40%)
  • Frequent skin relapses
  • Multifocality / nodal involvement have a similar prognosis as skin only lesions
  • No difference in behavior between anaplastic and nonanaplastic morphology
Case reports
Postulated normal counterpart
  • Transformed / activated skin-homing T lymphocyte
Clinical images

Images hosted on other servers:

Shin

Gross description
  • Solitary / multifocal papules / nodules / tumors
Microscopic (histologic) description
  • Diffuse, usually non-epidermotropic infiltrates of cohesive sheets of large CD30+ cells with anaplastic morphology (abundant cytoplasm, round / oval / irregular nuclei, prominent eosinophilic nucleoli)
  • Nonanaplastic appearance (pleomorphic or immunoblastic) is less common (20% - 25%)
  • Ulcerating lesions may show lymphomatoid papulosis-like histology with an inflammatory background (reactive T cells, histiocytes, eosinophils, neutrophils), relatively few CD30+ cells, prominent epidermal hyperplasia
  • Rare neutrophil rich (pyogenic) variant with extremely prominent inflammatory background
Microscopic (histologic) images

Images hosted on other servers:

CD30 immunostain

Positive stains
Negative stains
Molecular / cytogenetics description
  • Clonal TCR gene rearrangements in most cases (> 90%), but no specific / consistent cytogenetic abnormalities
  • No translocations involving the ALK gene at chromosome 2
Differential diagnosis
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