title: Primary cutaneous Langerhans cell sarcoma without Birbeck granules: indeterminate cell sarcoma?
abstract: An 88-year-old white male presented with a rapidly growing skin nodule on the scalp. Clinically, the nodule did not appear unusual for an ordinary cutaneous neoplasm on sun-exposed skin of an elderly white male. Histopathological examination showed sheet-like epithelioid tumor cell growth with a vaguely nested pattern and frank malignant features, resembling malignant melanoma. However, the tumor cells possessed irregularly convoluted nuclei with nuclear groves, frequent multinucleation and fine vesicular cytoplasm, features highly suggestive of histiocytes. Immunohistochemistry studies showed that the tumor cells were diffusely positive for S-100 protein and CD1a and negative for HMB-45, Melan-A, cytokeratin and CD30. The provisional diagnosis of Langerhans cell sarcoma was thus favored. To confirm this diagnosis, electron microscopic examination was performed. Although classic features of histiocytes were readily identifiable, no Birbeck granules could be found upon a thorough search on repeated sections. These results are indicative of the indeterminate cell nature of the tumor. We propose a diagnosis of primary cutaneous indeterminate cell sarcoma for this unusual histiocytic neoplasm. Current classification of histiocytic neoplasms and differential diagnosis are reviewed.
authors.affiliation: Department of Dermatology, University of Maryland, Baltimore, MD 21201-1734, USA. adeng@som.umaryland.edu
authors.forename: April
authors.initials: A
authors.lastname: Deng
authors.forename: Wendy
authors.initials: W
authors.lastname: Lee
authors.forename: Richard
authors.initials: R
authors.lastname: Pfau
authors.forename: Allan
authors.initials: A
authors.lastname: Harrington
authors.forename: John
authors.initials: J
authors.lastname: DiGiovani
authors.forename: Kyle A
authors.initials: KA
authors.lastname: Prickett
authors.forename: David M
authors.initials: DM
authors.lastname: Dare
authors.forename: John P
authors.initials: JP
authors.lastname: Petrali
mesh_terms: D000369:Aged, 80 and over; D018949:Antigens, CD1 / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D002467:Cell Nucleus / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D006644:Histiocytes / Q000648:ultrastructure; D006801:Humans; D007124:Immunoenzyme Techniques; D054752:Langerhans Cell Sarcoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D007801:Langerhans Cells / Q000737:chemistry / Q000473:pathology*; D008297:Male; D009418:S100 Proteins / Q000032:analysis; D012535:Scalp; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery
chemical_list: D018949:Antigens, CD1; D014408:Biomarkers, Tumor; C419393:CD1a antigen; D009418:S100 Proteins