title: Primary osteosarcoma of the breast: report of 2 cases.
abstract: Two distinct histologic variants of primary breast osteosarcoma in 2 elderly women are described. The first patient was an 88-year-old woman with a long-standing, slow-growing, 18-cm mass in her right breast. The second patient was a 96-year-old woman with a recently self-detected, painless, 7.5-cm lump in her left breast. Clinically, there was no evidence of metastasis, and both women underwent simple mastectomy. Histologic features of both specimens were those of high-grade primary breast osteosarcoma. The first patient's tumor was classified as a chondroblastic variant, and the second as an osteoblastic variant of osteosarcoma. The patients were alive without evidence of local recurrence or hematogenous spread at a 16- and 4-month follow-up, respectively. Primary mammary osteosarcoma should be distinguished from metaplastic/sarcomatoid carcinoma with heterologous osseous/cartilaginous differentiation or malignant phyllodes tumor because it has a different biological behavior and requires a different treatment approach.
authors.affiliation: Department of Pathology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Armita
authors.initials: A
authors.lastname: Bahrami
authors.forename: Erika
authors.initials: E
authors.lastname: Resetkova
authors.forename: Jae Y
authors.initials: JY
authors.lastname: Ro
authors.forename: Joe D
authors.initials: JD
authors.lastname: Ibañez
authors.forename: Alberto G
authors.initials: AG
authors.lastname: Ayala
mesh_terms: D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D002349:Carpal Tunnel Syndrome / Q000150:complications; D003937:Diagnosis, Differential; D005260:Female; D006333:Heart Failure / Q000150:complications; D006801:Humans; D007037:Hypothyroidism / Q000150:complications; D007150:Immunohistochemistry; D012516:Osteosarcoma / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D003557:Phyllodes Tumor / Q000473:pathology; D012509:Sarcoma / Q000473:pathology; D013921:Thrombocytopenia / Q000150:complications