Because the mass in this patient was solid and obstructing the rectal outlet, biopsy was performed after colonoscopy. The mass was determined to be metastatic invasive lobular carcinoma of the breast. Several immunohistochemical studies were performed. E-cadherin findings were negative, consistent with a diagnosis of metastatic breast cancer. BRST2 findings were strongly positive. The progesterone receptor findings were negative. The HER2/neu finding was 2+, and fluorescence in situ hybridization analysis was negative. The tumor cells were positive for ER, CK7, and AE1/AE3 and were negative for CA125, CK20, MOC-31, CD45, and Ber-EP4. Histologic immunohistochemistries were strongly suggestive of metastatic invasive lobular carcinoma of the breast.
Arteriovenous malformations do not typically present as acute obstructions; lower gastrointestinal bleeding is more common. Hemorrhoids most often present with long-term intermittent bleeding. A rectal polyp is usually small and asymptomatic. Diverticulosis presents with intermittent pain in the event of diverticulitis. Of the choices above, only a solid mass, such as metastasis, is consistent with this subacute presentation. Biopsy clarified and confirmed the diagnosis.
The most common metastatic sites of breast cancer are well known: the lungs, bones, liver, and brain. Involvement of the gastrointestinal tract remains unusual. Borst and Ingold published a large series that analyzed more than 2500 cases of breast cancer with metastatic disease over 18 years; they found that only 17 patients (less than 1%) had metastasis to the gastrointestinal tract.McLemore and colleagues also reported that infiltrating lobular carcinoma represented 64% of cases of gastrointestinal metastasis among breast cancer metastasis. Even in patients with mixed ductal and lobular primary breast carcinoma, the lobular type is most likely to cause metastatic disease. Metastasis to the gastrointestinal tract, such as the rectum, owing to breast cancer is a rare condition and is difficult diagnose. This diagnosis should be suspected when the patient has a history of lobular breast cancer.
This case serves as a reminder that, in a patient with history of cancer, evaluating a mass as a possible recurrence or metastasis is important—especially because constipation is a common problem among patients with cancer, owing to treatment or other conditions. A constipated patient may present with abdominal bloating, pain during defecation, rectal bleeding, diarrhea, low back pain, unexpected weight loss, inability to pass flatus, or vomiting. Understanding the many differential diagnoses associated with constipation is important. Among the factors to consider are the age of patient, acute or chronic presentation, an inherent gastrointestinal problem, comorbid problems (eg, neurologic conditions, endocrinopathies, motility problems), and medication use. Common differential diagnoses associated with constipation include hernias, colon cancer, ileus, and irritable bowel syndrome. Diet-related factors that should be considered include diabetes, lead poisoning, spinal cord injuries, and medications that can cause constipation. Rare causes include Chagas disease, panhypopituitarism, hypothyroidism, or peritonitis.
A detailed history of the constipated patient should include questions about normal patterns of defecation, frequency, and laxative use. Understanding how much fluid the patient drinks daily and information about movement and walking are also important. A cancer-related condition is not a likely cause of constipation for patients younger than 50 years and for those who have had the same symptoms for longer than 2 years. Ileus is usually associated with volvulus and an acute presentation. Volvulus is mostly found in young patients or in those with previous abdominal surgery and presents with abdominal pain secondary to a mechanical defect in the colon. Ileus may be secondary to psychiatric conditions, medications, or changes in diet.
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Cite this: Winston Tan, Matthew Tan. A 61-Year-Old Woman With Painful Constipation - Medscape - Oct 12, 2017.