%0 Journal Article %T Malignant Phyllodes Tumour with Liposarcomatous Differentiation, Invasive Tubular Carcinoma, and Ductal and Lobular Carcinoma In Situ: Case Report and Review of the Literature %A Mardiana Abdul Aziz %A Frank Sullivan %A Michael J. Kerin %A Grace Callagy %J Pathology Research International %D 2010 %I Hindawi Publishing Corporation %R 10.4061/2010/501274 %X A 43-year-old woman presented with a right breast lump that had enlarged over 5 months. She had chemoradiotherapy for non-Hodgkin¡¯s lymphoma in 1989. Histology revealed a malignant phyllodes tumour (PT) with liposarcomatous differentiation and ductal carcinoma in situ (DCIS) within the tumour with invasive tubular carcinoma, DCIS, and lobular carcinoma in situ in the surrounding breast. She had surgery and adjuvant radiotherapy. One year follow-up showed no recurrence or metastatic disease. Liposarcomatous differentiation is uncommon in PTs, and coexisting carcinoma is rare with 38 cases in 31 reports in the literature. Carcinoma is reported in malignant ( ), benign ( ) and in borderline PTs ( ) with invasive carcinoma ( ) and pure in situ carcinoma ( ) recorded in equal frequency. Carcinoma is more commonly found within the confines of benign PTs; whereas it is more often found surrounding the PT or in the contralateral breast in malignant PTs. Previous radiotherapy treatment is reported in only two cases. The aetiology of co-existing carcinoma is unclear but the rarity of previous radiotherapy treatment suggests that it is incidental. This case highlights the diverse pathology that can occur with PTs, which should be considered when evaluating pathology specimens as they may impact on patient management. 1. Introduction Phyllodes tumors (PTs) of the breast are uncommon biphasic fibroepithelial neoplasms that account for <1% of all breast tumours. Most PTs are benign and carry a risk of local recurrence whereas malignant PTs have a 13% risk of haematogenous metastasis [1].The distinction between benign, borderline and malignant PT is based on the assessment of a number of histological features including infiltrative margin, stromal overgrowth, stromal atypia, cellularity, and mitotic activity.However,while histological features are helpful, they are not accurate predictors of tumour behavior, and no single parameter is reliable in all cases [2]. PTs are believed to arise from intralobular or periductal stroma and may arise de novo or from pre-existing fibroadenomas [2]. Up to 30% of PTs show malignant transformation, most often in the form of malignant transformation of the stroma, which usually shows fibrosarcomatous differentiation and rarely heterologous sarcomatous elements. Malignant transformation of epithelial elements is very rare with only 38 cases reported in the literature. We present a case of a malignant PT that contained heterologous liposarcomatous stromal differentiation and exhibited a range of epithelial pathology. Ductal carcinoma in %U http://www.hindawi.com/journals/pri/2010/501274/