Invasive lobular carcinoma of the breast has similar patterns of metastatic disease when compared to invasive ductal carcinoma; however, lobular carcinoma metastasizes to unusual sites more frequently. We present a 65-year-old female with a history of invasive lobular breast carcinoma (T3N3M0) treated with modified radical mastectomy and aromatase-inhibitor therapy who underwent a surveillance PET scan, which showed possible sigmoid cancer. Colonoscopy with biopsy revealed a 3 cm sigmoid adenocarcinoma. The patient underwent a lower anterior resection. Pathology showed an ulcerated, invasive moderately differentiated adenocarcinoma extending into but not through the muscularis propria. However, six of seventeen paracolonic lymph nodes were positive for metastatic breast carcinoma (ER+/PR+), consistent with her lobular primary breast carcinoma; there was no evidence of metastatic colon cancer. This case highlights the unusual metastatic patterns of lobular carcinoma.
A 65-year-old female with a history of invasive lobular breast carcinoma (T3N3M0) treated with modified radical mastectomy and aromatase-inhibitor therapy underwent a surveillance PET scan approximately three years later, which showed possible sigmoid cancer (Figure
The patient underwent a lower anterior resection. Pathology showed an ulcerated, invasive moderately differentiated adenocarcinoma extending into but not through the muscularis propria (Figure
Primary lobular carcinoma.
Primary colon adenocarcinoma.
Pericolonic lymph node with positive mammaglobin staining.
PET CT scan with avid FDG uptake associated with the sigmoid colon.
Hematology/oncology was consulted regarding her metastatic invasive lobular breast carcinoma. They discontinued her tamoxifen and started her on Arimidex. The patient had a recent PET scan, which showed no signs of recurrent disease.
One in twelve American women develop breast cancer, and infiltrating lobular carcinoma (ILC) involves around 10% of these cases [
For instance, Ferlicot et al. showed more diverse patterns of tumor spread in ILC when compared to IDC. There was a statistically significant difference in metastatic spread in the bones, lung, and abdominal organs. In ILC, metastatic spread was seen more frequently in the bones and abdominal region whereas IDC metastasized to the lung. There was no difference in liver, nonaxillary lymph nodes, or the central nervous system [
Other studies have shown similar findings especially in postmortem examinations. Metastatic ILC was seen more frequently in the ovaries, uterus, peritoneum, retroperitoneum, stomach, and intestine on autopsy [
It is not common to see colonic involvement in patients with a history of ILC; as high as 12% has been cited in the literature [
It is important that clinicians be cognizant that ILC has a much wider and different pattern of metastatic disease when compared to IDC. Metastatic ILC must be in the differential diagnosis in a patient with a history of ILC presenting with abdominal complaints or an incidental finding seen on the screening imaging, even if the patient has been disease-free for several years.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors thank Dr. Teresita Zdunek a pathologist at the Saint Joseph Hospital who provided the slides for this paper.