title: Primary cutaneous diffuse leiomyosarcoma with desmoplasia.
abstract: A 65-year-old man presented with an indurated plaque over his left cheek and left neck. An initial punch biopsy of skin showing increased smooth muscle bundles was consistent with a diagnosis of smooth muscle hamartoma. A second incisional skin biopsy revealed a well-differentiated smooth muscle proliferation invading into the dermis and subcutaneous fat in a diffusely infiltrative pattern and with a desmoplastic component, suggesting a diagnosis of desmoplastic leiomyosarcoma. Resection of the tumour confirmed the presence of a cytologically low grade leiomyosarcoma with an insidious infiltrative growth pattern. This rare pattern of diffuse leiomyosarcoma is important to recognize as the histological features are subtle and may potentially constitute a pitfall in histological diagnosis in a small biopsy specimen. In addition, our case illustrates overlapping morphology between diffuse and desmoplastic types of leiomyosarcoma.
authors.affiliation: Skin and Cancer Foundation Australia, Darlinghurst, New South Wales, Australia. cchoy@scfa.edu.au
authors.forename: Carolyn
authors.initials: C
authors.lastname: Choy
authors.forename: Alan
authors.initials: A
authors.lastname: Cooper
authors.forename: Steven
authors.initials: S
authors.lastname: Kossard
mesh_terms: D000368:Aged; D002610:Cheek / Q000473:pathology; D003131:Combined Modality Therapy; D003896:Desmosomes / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007890:Leiomyosarcoma / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D008297:Male; D009333:Neck / Q000473:pathology; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery