title: Spindle cell squamous cell carcinoma showing continuous mesenchymal dedifferentiation in a single tumor.
abstract: We report the case of an 85-year-old man who presented with an enlarging tumor on the right temple. Histologically, spindle-shaped cells were proliferating continuously within well-differentiated squamous cell carcinoma that was immunohistochemically negative for vimentin and alpha-smooth muscle actin (ASMA) but positive for cytokeratin (AE1/3). These spindle-shaped cells expressed vimentin and ASMA but not cytokeratin (AE1/3). Intermediate cells with round nuclei and small amounts of cytoplasm displayed slight expression of vimentin, ASMA, and cytokeratin. This case illustrated spindle cell squamous cell carcinoma with mesenchymal metaplasia of malignant epithelial cells.
authors.affiliation: Department of Dermatology, Kochi Medical School, Nankoku, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Seike
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Ikeda
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakajima
authors.forename: Hajime
authors.initials: H
authors.lastname: Kodama
mesh_terms: D000199:Actins / Q000032:analysis; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000473:pathology*; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008297:Male; D008648:Mesoderm / Q000473:pathology; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*; D014746:Vimentin / Q000032:analysis
chemical_list: D000199:Actins; D014746:Vimentin; D007633:Keratins