title: Lipophyllodes of the breast. A reappraisal of fat-rich tumors of the breast based on 22 cases integrated by immunohistochemical study, molecular pathology insights, and clinical follow-up.
abstract: We have studied 22 cases of mammary lipophyllodes tumors (LPT), analyzing their clinicopathologic features along with available follow-up. All cases were tested for cytokeratins, S100 protein, and MDM2, and in selected cases for estrogen receptor, smooth muscle actin, bcl2, desmin, and myogenin. Patients were women aged 21 to 69 years (average, 45 years), and LPT size ranged from 1.6 to 30 cm (average, 9.7 cm). Microscopically, LPT segregated as follows: atypical lipoma-like tumor/well-differentiated liposarcoma (ALT/WDL), 8 cases; myxoid, 6; and pleomorphic/poorly differentiated/round cell, 8, including a case of dedifferentiated liposarcoma. Immunohistochemistry studies showed focal positive staining for S100 and CD34 in most ALT/WDL, and desmin and myogenin in 2 cases with evidence of rhabdomyoblastic differentiation. MDM2 positivity was focally seen in 1 case. Follow-up was available in 8 cases. Multiple recurrent tumors were seen in 2 patients, and metastatic disease to the lung was seen in 2 patients. In 4 patients with a follow-up between 2 and 15 years there was no evidence of recurrent or metastatic disease. Patients with ALT/WDL (2/2) were alive with no evidence of disease; 2 of 4 patients with myxoid liposarcoma component experienced tumor recurrence, whereas pleomorphic liposarcoma LPT pursued a less favorable course although only 1 patient died of the condition. Absence of MDM2 reactivity in most cases seems not as meaningful as in fatty tumors of somatic soft parts.
authors.affiliation: Lab Bacchi, Botucatu, SP, Brazil.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Bacchi
authors.affiliation: Lab Bacchi, Botucatu, SP, Brazil.
authors.forename: Sheila C
authors.initials: SC
authors.lastname: Wludarski
authors.affiliation: Department of Pathology, Institute of Oncology, Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Lamovec
authors.affiliation: Department of Pathology, The Barzilai Medical Center, Ashkelon, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Ben Dor
authors.affiliation: Department of Pathology, University of Trieste School of Medicine, Trieste, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Ober
authors.affiliation: Department of Pathology, University of Trieste School of Medicine, Trieste, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Salviato
authors.affiliation: Department of Pathology, University of Trieste School of Medicine, Trieste, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Zanconati
authors.affiliation: Department of Pathology, General University Hospital, Udine, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: De Maglio
authors.affiliation: Department of Pathology, General University Hospital, Udine, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Pizzolitto
authors.affiliation: Department of Pathology, General University Hospital, Udine, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Sioletic
authors.affiliation: Department of Pathology, University of Trieste School of Medicine, Trieste, Italy. Electronic address: dr.g.falconieri@gmail.com.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Falconieri
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001940:Breast / Q000378:metabolism / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008067:Lipoma / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D008080:Liposarcoma / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D003557:Phyllodes Tumor / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D051736:Proto-Oncogene Proteins c-mdm2
keywords: Immunohistochemistry; Lipophyllodes; MDM2; Phyllodes tumor