Case report
Invasive lobular carcinoma of the breast presenting as retroperitoneal fibrosis: a case report
- Equal contributors
1 Department of Laboratory Medicine, and the Keenan Research Centre in the Li Ka Shing Knowledge Institute. St. Michael's Hospital, Toronto, Ontario, Canada
2 Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
3 Department of Pathology, London Health Sciences Center, University of Western Ontario, London, Ontario, Canada
4 Division of Urology, Department of Surgery, St. Michael's Hospital Toronto, University of Toronto, Ontario, Canada
Journal of Medical Case Reports 2010, 4:175 doi:10.1186/1752-1947-4-175
Published: 9 June 2010Abstract
Introduction
Invasive lobular carcinoma of the breast represents approximately 6.3% of mammary malignancies. Distant metastasis of invasive lobular carcinoma to the peritoneum or retroperitoneum has been reported fairly frequently.
Case presentation
We report the case of a 59-year-old Caucasian-Canadian woman with invasive lobular carcinoma of the breast presenting with retroperitoneal fibrosis and bilateral ureteral obstruction. Intra-operative pathology consultation did not reveal malignancy. The diagnosis, however, was confirmed on permanent sections by histological appearance in addition to immunohistochemistry. To the best of our knowledge, this is the first reported case of invasive lobular carcinoma of the breast presenting with retroperitoneal fibrosis.
Conclusion
In a case of unexplained ureteric obstruction and retroperitoneal fibrosis, more comprehensive physical examination and additional ancillary studies may be warranted to rule out malignancy as an underlying etiology. This case also emphasizes that intra-operative frozen section consultation cannot always be fully relied upon to exclude a malignancy as the etiology of retroperitoneal fibrosis. Moreover, in permanent histopathology sections, immunohistochemistry testing can be of value to rule out metastatic disease where the morphology is not salient. There is a need for a thorough physical examination of patients with retroperitoneal fibrosis, including the breast and gynecological organs.



