Metastatic lobular carcinoma of the breast: Patterns of spread in the chest, abdomen, and pelvis on CT

OBJECTIVE. We determined the pattern of spread of metastatic lobular carcin oma in the chest, abdomen, and pelvis on CT. MATERIALS AND METHODS. We identified 57 women (age range, 30-79 years: mean age, 57 years) with metastatic lobular carcinoma of the breast who underwe nt CT of the chest, abdomen, or pelvis between 1995 and 1998. Then two expe rienced oncology radiologists retrospectively reviewed 78 CT examinations o f those patients to identify sites of metastatic disease and to identify co mplications caused by metastases. RESULTS. Metastases were identified in bone in 46 patients (81%), lymph nod es in 27 patients (47%), lung in 19 patients (33%), liver in 18 patients (3 2%), peritoneum in 17 patients (30%), colon in 15 patients (26%), pleura in 13 patients (23%), adnexa in 17 patients (21%), stomach in nine patients ( 16%), retroperitoneum in nine patients (16%), and small bowel in six patien ts (11%). Eighteen patients (32%) had gastrointestinal tract involvement th at manifested as bowel wall thickening. Hydronephrosis was present in six p atients (11%). CONCLUSION. Although lobular carcinoma metastasized to common metastatic si tes of infiltrating ductal carcinoma, lobular carcinoma frequently metastas ized to unusual sites, including the gastrointestinal tract, peritoneum, an d adnexa. Gastrointestinal tract involvement was as frequent as liver invol vement, appearing as bowel wall thickening on CT. Hydronephrosis was a comp lication of metastatic lobular carcinoma.