A 64-year-old man underwent left mastectomy for carcinoma of the breast at Teikyo University Hospital. Microscopic and immunohistochemical examination revealed estrogen-receptor-positive invasive ductal carcinoma without lymph node involvement. The patient received antiestrogen therapy for 6 months, and the clinical follow-up showed no signs of tumor recurrence. After a disease-free interval of 3 years, multiple liver metastases were detected, and antiestrogen therapy was resumed. Although the liver metastases decreased in size and there was no change in the patient’s condition, he was admitted to our hospital after 4 years for anemia and blood in his stools. A barium enema showed rectal stenosis ([Fig. 1]), and a computed tomography scan demonstrated eccentric thickening of the wall of the rectum ([Fig. 2]). Colonoscopy revealed edema and yellowish-white polypoid lesions in the rectal mucosa ([Fig. 3]). A rectal biopsy showed diffuse tissue infiltration by tumor cells ([Fig. 4]). Immunohistochemical staining for estrogen receptor showed positive ([Fig. 5]). The pathologist classified the tumor as metastasis of invasive ductal carcinoma of the breast. The patient was treated with hormonal therapy. A barium enema carried out after hormonal therapy showed that the rectal stenosis had improved. At the present time, he is doing well as an outpatient and has not had any complaints.
Fig. 1 Barium enema showed rectal stenosis.
Fig. 2 Computed tomography demonstrated eccentric thickening of the wall of the rectum.
Fig. 3 Colonoscopy revealed edema and yellowish-white polypoid leasions in the rectal mucosa.
Fig. 4 Rectal biopsy showed diffuse tissue infiltration by tumor cells.
Fig. 5 Immunohistochemical staining for estrogen receptor showed positive.
Rectal metastasis of invasive ductal carcinoma is very rare [1]
[2]; second primary malignancies are more common than gastrointestinal tract metastases in patients with a history of breast cancer [3]. For this reason, we first diagnosed the rectal lesion as a type-4 rectal cancer, because the mucosa of the rectum was edematous, granular, and gyriform-like in appearance. Immunohistochemical staining for estrogen receptor as well as the histological findings were also useful for establishing the diagnosis. Since patients with colorectal metastatic lesions of breast cancer have widespread metastases, systemic treatment with anticancer drugs and hormonal agents is recommended as first-line treatment.
Endoscopy_UCTN_Code_CCL_1AD_2AC
