Primary cutaneous ALCL with phosphorylated/activated cytoplasmic ALK and novel phenotype: EMA/MUC1+, cutaneous lymphocyte antigen negative

Am J Surg Pathol. 2008 Sep;32(9):1421-6. doi: 10.1097/PAS.0b013e3181648d6d.

Abstract

Primary cutaneous anaplastic large-cell lymphoma (ALCL) ordinarily is distinguished from systemic ALCL by clinical presentation, absence of anaplastic lymphoma kinase (ALK) expression, and immunophenotype (CLA+, EMA/MUC1-). We present an exceptional case of an elderly man with primary cutaneous ALCL and no systemic disease for a 13-year period. Recurrent skin tumors in this patient were characterized by anaplastic, often multinucleated, cells infiltrating the lymphatics and associated with pseudoepitheliomatous hyperplasia. Cutaneous lymphocyte antigen was absent and EMA/MUC1, typical of systemic ALCL, was strongly expressed by the tumor cells. Remarkably, the tumor cells expressed a cytoplasmic-only variant of ALK protein, as reported in 3 previous cases of primary cutaneous ALCL. Fluorescence in situ hybridization revealed lack of rearrangements of the chromosome 2 ALK gene locus usually involved by translocation t(2;5) or other chromosomal rearrangements that generate nucleophosmin-ALK or the variant ALK fusions that occur in systemic ALCL. Nonetheless, the cytoplasmic ALK protein in the patient's tumor cells was shown to be phosphorylated/activated, suggesting a novel mechanism of ALK activation. Primary cutaneous ALCL of this novel subtype should be distinguished from systemic ALCL to ensure proper clinical management.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age of Onset
  • Aged
  • Anaplastic Lymphoma Kinase
  • Antigens, Differentiation, T-Lymphocyte
  • Antigens, Neoplasm / biosynthesis
  • Enzyme Activation / physiology
  • Humans
  • In Situ Hybridization, Fluorescence
  • Lymphoma, Large-Cell, Anaplastic / genetics
  • Lymphoma, Large-Cell, Anaplastic / metabolism*
  • Lymphoma, Large-Cell, Anaplastic / pathology*
  • Male
  • Membrane Glycoproteins / biosynthesis
  • Middle Aged
  • Mucin-1 / biosynthesis
  • Neoplasm Recurrence, Local / metabolism
  • Neoplasm Recurrence, Local / pathology
  • Phenotype
  • Phosphorylation
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Receptor Protein-Tyrosine Kinases
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology*

Substances

  • Antigens, Differentiation, T-Lymphocyte
  • Antigens, Neoplasm
  • CTAGE1 protein, human
  • Membrane Glycoproteins
  • Mucin-1
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases