Cytomorphologic features of primary anaplastic large cell lymphoma of the psoas muscle: a case report and literature review

Diagn Cytopathol. 2010 Mar;38(3):208-12. doi: 10.1002/dc.21174.


Ki-1 (CD30) positive anaplastic large cell lymphoma (ALCL) is an uncommon malignancy, which may present with nodal as well as extra-nodal disease. Primary skeletal muscle Ki-1 (CD30) positive ALCL is an even rarer event with few cases reported in the literature and only some with published cytomorphologic features. An 83-year-old woman underwent a fine needle aspiration (FNA) of a psoas muscle mass. Smears demonstrated a predominantly discohesive population of large pleomorphic cells. The nuclei were hypechromatic and lobulated, with often multinucleation. Nucleoli were prominent in a subset of cells. Cytoplasmic vacuolization was also present. No lymphoglandular bodies were identified. A cytodiagnosis of malignant cells favoring metastatic melanoma vs. poorly differentiated carcinoma was rendered. Morphologic and immunohistochemical features later revealed a primary psoas muscle Ki-1 (CD30) positive ALCL with negative staining for anaplastic large cell lymphoma kinase (ALK). Cytologic features of ALCL mimic epithelial neoplasms, sarcomas, melanoma and other lymphomas. Although rare, ALCL should be a diagnostic consideration when discohesive pleomorphic malignant cells are encountered on FNA of a muscle neoplasm.

Publication types

  • Case Reports

MeSH terms

  • Aged, 80 and over
  • Anaplastic Lymphoma Kinase
  • Biomarkers, Tumor / metabolism
  • Biopsy, Fine-Needle
  • Carcinoma / diagnosis
  • Cell Nucleus / metabolism
  • Cell Nucleus / pathology
  • Diagnosis, Differential
  • Female
  • Humans
  • Ki-1 Antigen / metabolism
  • Lymphoma, Large-Cell, Anaplastic / metabolism
  • Lymphoma, Large-Cell, Anaplastic / pathology*
  • Melanoma / diagnosis
  • Melanoma / secondary
  • Muscle Neoplasms / metabolism
  • Muscle Neoplasms / pathology*
  • Protein-Tyrosine Kinases / metabolism
  • Psoas Muscles / metabolism
  • Psoas Muscles / pathology*
  • Receptor Protein-Tyrosine Kinases
  • Skin Neoplasms / diagnosis


  • Biomarkers, Tumor
  • Ki-1 Antigen
  • ALK protein, human
  • Anaplastic Lymphoma Kinase
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases