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 .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 . PTs are believed to arise from intralobular or periductal stroma and may arise de novo or from pre-existing fibroadenomas . 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
J. R. Parfitt, C. Armstrong, F. O'Malley, J. Ross, and A. B. Tuck, “In-situ and invasive carcinoma within a phyllodes tumor associated with lymph node metastases,” World Journal of Surgical Oncology, vol. 2, article 46, 2004.
R. Yamaguchi, M. Tanaka, Y. Kishimoto, K. Ohkuma, M. Ishida, and M. Kojiro, “Ductal carcinoma in situ arising in a benign phyllodes tumor: report of a case,” Surgery Today, vol. 38, no. 1, pp. 42–45, 2008.
M. J. Ramdass and S. Dindyal, “Phyllodes breast tumour showing invasive squamous-cell carcinoma with invasive ductal, clear-cell, secretory, and squamous components,” Lancet Oncology, vol. 7, no. 10, p. 880, 2006.
G. de Rosa, G. Ferrara, P. Goglia, C. Chicas, and P. Zeppa, “In situ and microinvasive carcinoma with squamoid differentiation arising in a phyllodes tumor: report of a case,” Tumori, vol. 75, no. 5, pp. 514–517, 1989.
L. Christensen, M. Nielsen, and P. M. Madsen, “Cystosarcoma phyllodes: a review of 19 cases with emphasis on the occurrence of associated breast carcinoma,” Acta Pathologica Microbiologica et Immunologica Scandinavica, Section A, vol. 94, no. 1, pp. 35–41, 1986.
T. Ishida, M. Izuo, and T. Kawai, “Breast carcinoma arising in cystosarcoma phyllodes: report of a case with a review of the literature,” Japanese Journal of Clinical Oncology, vol. 14, no. 1, pp. 99–106, 1984.
A. Korula, J. Varghese, M. Thomas, F. Vyas, and A. Korula, “Malignant phyllodes tumour with intraductal and invasive carcinoma and lymph node metastasis,” Singapore Medical Journal, vol. 49, no. 11, pp. e318–e321, 2008.
M. Kefeli, L. Yildiz, I. Akpolat, P. Balci, and N. Ozen, “The coexistence of invasive ductal carcinoma and malignant phyllodes tumor with liposarcomatous and chondrosarcomatous differentiation in the same breast in a post-osteosarcoma case,” Pathology Research and Practice, vol. 204, no. 12, pp. 919–923, 2008.
T. Sugie, E. Takeuchi, F. Kunishima, F. Yotsumoto, and Y. Kono, “A case of ductal carcinoma with squamous differentiation in malignant phyllodes tumor,” Breast Cancer, vol. 14, no. 3, pp. 327–332, 2007.
B. Merck, P. Cansado Martinez, M. Pérez Ramos, N. Martínez Banaclocha, F. J. Lacueva Gómez, and R. Calpena, “Infiltrating ductal carcinoma and synchronous malignant phyllodes tumour: diagnostic and therapeutic approaches,” Clinical and Translational Oncology, vol. 8, no. 11, pp. 830–832, 2006.
L. H. Gebrim, J. R. Bernardes Júnior, A. C. Nazário, C. Kemp, and G. R. Lima, “Malignant phyllodes tumor in the right breast and invasive lobular carcinoma within fibroadenoma in the other: case report,” Sao Paulo Medical Journal, vol. 118, no. 2, pp. 46–48, 2000.
M. Kasami, M. Yoshida, J. Isogaki, et al., “Bilateral breast tumors, malignant phyllodes tumor and invasive lobular carcinoma in a 46,XX/46,XY mosaic female with family history of breast cancer,” Pathology International, vol. 47, no. 2-3, pp. 147–154, 1997.
T. Morimoto, T. Tanaka, K. Komaki, et al., “The coexistence of lobular carcinoma in a fibroadenoma with a malignant phyllodes tumor in the opposite breast: report of a case,” Surgery Today, vol. 23, no. 7, pp. 656–660, 1993.
P. A. Isotalo, R. L. George, R. Walker, and S. K. SenGupta, “Malignant phyllodes tumor with liposarcomatous differentiation,” Archives of Pathology and Laboratory Medicine, vol. 129, no. 3, pp. 421–422, 2005.
A. M. Jones, R. Mitter, R. Springall, et al., “A comprehensive genetic profile of phyllodes tumours of the breast detects important mutations, intra-tumoral genetic heterogeneity and new genetic changes on recurrence,” Journal of Pathology, vol. 214, no. 5, pp. 533–544, 2008.
A. Kuijper, A. M. Snijders, E. M. J. J. Berns, et al., “Genomic profiling by array comparative genomic hybridization reveals novel DNA copy number changes in breast phyllodes tumours,” Cellular Oncology, vol. 31, no. 1, pp. 31–39, 2009.
E. J. Sawyer, A. M. Hanby, P. Ellis, et al., “Molecular analysis of phyllodes tumors reveals distinct changes in the epithelial and stromal components,” American Journal of Pathology, vol. 156, no. 3, pp. 1093–1098, 2000.
E. J. Sawyer, A. M. Hanby, A. J. Rowan, et al., “The Wnt pathway, epithelial-stromal interactions, and malignant progression in phyllodes tumours,” Journal of Pathology, vol. 196, no. 4, pp. 437–444, 2002.