title: Cytomorphologic features of primary anaplastic large cell lymphoma of the psoas muscle: a case report and literature review.
abstract: 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.
authors.affiliation: Department of Pathology at the Medical University of South Carolina, Charleston, South Carolina 29425, USA. r_recavarren@hotmail.com
authors.forename: Rosemary A
authors.initials: RA
authors.lastname: Recavarren
authors.forename: Jack
authors.initials: J
authors.lastname: Yang
mesh_terms: D000369:Aged, 80 and over; D000077548:Anaplastic Lymphoma Kinase; D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D002277:Carcinoma / Q000175:diagnosis; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D017730:Ki-1 Antigen / Q000378:metabolism; D017728:Lymphoma, Large-Cell, Anaplastic / Q000378:metabolism / Q000473:pathology*; D008545:Melanoma / Q000175:diagnosis / Q000556:secondary; D019042:Muscle Neoplasms / Q000378:metabolism / Q000473:pathology*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016658:Psoas Muscles / Q000378:metabolism / Q000473:pathology*; D020794:Receptor Protein-Tyrosine Kinases; D012878:Skin Neoplasms / Q000175:diagnosis
chemical_list: D014408:Biomarkers, Tumor; D017730:Ki-1 Antigen; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases