title: Osteosarcoma of the femur mimicking Ewing sarcoma/primitive neuroectodermal tumour on biopsy and metastatic carcinoma on resection.
abstract: Osteosarcoma (OS) is known to have several morphological appearances, small cell osteosarcoma and epithelioid osteosarcoma being two well recognized patterns. The former can be mistaken for a Ewing sarcoma/primitive neuroectodermal tumour (ES/PNET), whereas the latter mimics metastatic carcinoma. Herein we present an osteosarcoma in a 17-year-old girl that was diagnosed as an ES/PNET on biopsy; however, the resected specimen revealed a very unusual morphology mimicking a metastatic carcinoma with a sex cord stromal tumour-like pattern.
authors.affiliation: Department of Pathology, Tata Memorial Hospital, E. Borges Marg, Parel, Mumbai, 400 012, India. najambhekar@rediffmail.com
authors.forename: Nirmala Ajit
authors.initials: NA
authors.lastname: Jambhekar
authors.forename: Manish
authors.initials: M
authors.lastname: Agarwal
authors.forename: Pallavi
authors.initials: P
authors.lastname: Suryawanshi
authors.forename: Saral
authors.initials: S
authors.lastname: Desai
authors.forename: Bharat
authors.initials: B
authors.lastname: Rekhi
authors.forename: Ashish
authors.initials: A
authors.lastname: Gulia
authors.forename: Ajay
authors.initials: A
authors.lastname: Puri
mesh_terms: D000293:Adolescent; D018278:Carcinoma, Neuroendocrine / Q000473:pathology* / Q000556:secondary* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D005266:Femoral Neoplasms / Q000175:diagnosis*; D006801:Humans; D012516:Osteosarcoma / Q000175:diagnosis*; D012512:Sarcoma, Ewing / Q000473:pathology* / Q000556:secondary* / Q000601:surgery