Unveiling the Unexpected: Duodenal Ulcer as a Manifestation of Breast Cancer Metastasis

Abstract

Breast cancer typically metastasizes to the lymph nodes, lungs, bones, and liver. However, gastrointestinal (GI) involvement is exceedingly rare, particularly presenting as duodenal ulcers. Such metastases often mimic primary GI malignancies, leading to nonspecific symptoms like abdominal pain, anorexia, bleeding, and vomiting, which can delay accurate diagnosis. Early recognition through appropriate diagnostic evaluations is crucial to prevent disease progression. We report a unique case of an 86-year-old woman with multiple comorbidities who presented with multiple gastrointestinal ulcers. Further investigation revealed these lesions to be manifestations of metastatic breast cancer. This case underscores the importance of considering metastatic breast cancer in the differential diagnosis of atypical gastrointestinal presentations, even in elderly patients without a known history of malignancy.

1. Introduction

Breast cancer, accounting for approximately 32 % of all cancers, is the most common malignancy in women, with a lifetime risk of 1 in 10 (Nazareno et al., 2006).1 The prognosis of this malignancy depends on the extent of the primary lesion, hormone receptor status, lymph node involvement, and the presence of metastatic disease (Nazareno et al., 2006).1 Although breast cancer metastasis to the gastrointestinal (GI) tract is rare, it has been well documented. Autopsy studies reveal GI tract involvement in 14 %–35 % of metastatic breast carcinoma cases, with 6 %–18 % showing gastric involvement (Reiman & Butts, 2001).2 Small bowel metastasis accounts for approximately 8 % of such cases, with duodenal involvement being particularly rare, as highlighted in prior case series.3 Recent reports suggest that gastric metastases from breast cancer can occur even decades after the initial diagnosis, sometimes as late as 20 years post-treatment. 4 Recent studies have shown that these metastases can present in many different ways from causing no symptoms at all to triggering severe gastrointestinal issues, making them especially challenging to diagnose.5 This case report presents an 86-year-old female whose initial symptoms of anemia, fatigue, and abdominal discomfort were ultimately found to be due to metastatic breast cancer.

2. Case report

An 86-year-old female patient with a history of atrial fibrillation on chronic anticoagulation with Eliquis, ureteric strictures secondary to stones in the past, having bilateral nephrostomy tubes, without a known family history of breast cancer, bilateral hysterectomy with bilateral oophorectomy, and poor oral intake was admitted from a nursing home. She presented with symptoms of weakness, fatigue, tarry stools, and a hemoglobin level of 6.7 g/dL. These symptoms had been ongoing for four days, and she also reported abdominal discomfort and pain. Physical examination revealed pallor, a soft and non-tender abdomen, and diffuse ecchymosis on her extremities. The patient was not on any medication at home except Eliquis. Laboratory workup revealed significantly worsened kidney function, with a serum creatinine of 1.97 mg/dL on admission compared to a baseline of 0.84 mg/dL documented six months prior in an outpatient clinic note. The patient was also found to have a complicated urinary tract infection and overlapping metabolic acidosis., as shown in Table 1.

Table 1.

Laboratory Investigations on admission.

Laboratory marker	Patient’s value on admission	Normal range
WBC count	10.63 10*3/uL	3.5–10.5 10*3/uL
RBC count	3.06 10*6/uL	3.9–5.03 10*6/uL
Hemoglobin	6.7	12.0–15.5 g/dl
Hematocrit	28.0	34.9–44.5 %
Absolute Neutrophils	9.35	2.5–7.0 10*3/uL
% Neutrophils	88.0 %	40–60 %
% Lymphocytes	8.0 %	20–40 %
Glucose	162	70–140
BUN	53	6.0–24.0 mg/dl
Creatinine	1.97	0.5–1.0 mg/dl
Chloride	108	96–106 mEq/L
eGFR	24	>90
Calcium, total	8.3	8.6–10.3 mg/dl
Protein, total	4.8	6.0–8.3 g/dl
Albumin, S	1.7	3.4–5.4 g/dl
Urinalysis
LEUCOCYTE ESTERASE, Urine	2+
Protein, Qual. Urine	3+
Urine Bacteria	Few
Urine Blood	3+
Urine Casts	>63
Urine RBC	1003
Urine WBC	240

On the first day of admission, a gastrointestinal consult was obtained for evaluation of anemia and melena. Esophagogastroduodenoscopy (EGD) revealed distal esophageal and multiple duodenal ulcers, gastritis, a small hiatal hernia, gastroesophageal reflux disease (GERD), and an epiphrenic diverticulum. Biopsies were obtained from ulcerated areas. The suspected peptic ulcer disease was managed conservatively with intravenous proton pump inhibitors and blood transfusions. Anticoagulation with Eliquis was held due to active bleeding and renal dysfunction. The patient remained hospitalized due to persistent clinical instability. Approximately two weeks later, biopsy results revealed estrogen receptor (ER)-positive tumor cells with immunohistochemistry consistent with metastatic carcinoma, most likely of breast origin, supported by positive CK7 and CK5/6 and negative p63, CK20, p40, GATA-3, and synaptophysin. D2–40 staining indicated lymphatic involvement. Histopathology images are included and labeled as Figs. 1 and 2.

Fig. 1.

Hematoxylin and eosin (H&E) stain of tissue section (magnification × 40). Black arrows indicate endothelial cells lining lymphatic vessels. Red arrows indicate tumor cells present within the lymphatic spaces.

Fig. 2.

Immunohistochemical stain for estrogen receptor (ER) (magnification × 40). Nuclei of tumor cells show positive staining, confirming ER expression.

The biopsy findings strongly suggested metastatic carcinoma, most likely of breast origin, further supported by skin and nipple changes on physical exam. Oncology consultation recommended letrozole, though initiation was deferred due to the patient’s unstable condition. Imaging revealed pulmonary nodules and bony metastases. Her hospital course was complicated by septic shock from a urinary tract infection, Influenza A pneumonia, and recurrent anemia requiring multiple transfusions. Given her poor prognosis and need for vasopressors, curative cancer treatment was not pursued, and goals-of-care discussions were prioritized. She passed away before breast imaging could confirm the primary tumor. This case highlights the diagnostic complexity of metastatic breast cancer presenting as gastrointestinal disease, often mimicking primary GI pathology.

3. Discussion

Breast cancer accounts for 19 % of mortality among women (Rubin et al., 1993, pp. 187–211).4 ]. Most types of metastases are more commonly seen with invasive lobular carcinoma (ILC) than with invasive ductal carcinoma (IDC). While the exact reason isn’t fully understood, some researchers suggest it may be linked to the natural tendency of lobular cells to spread in certain ways. Interestingly, even when the primary breast cancer has mixed features, it’s usually the lobular component that spreads widely through the gastrointestinal tract. In contrast, the few reported cases of ductal carcinoma spreading to the GI tract tend to show up as small, localized nodules in the stomach.5 Advances in current management strategies have had a substantial impact on both mortality and survival rates in breast cancer patients (Chu et al., 1996).6 Prognosis depends on several factors, including tumor type and grade, presence of metastatic disease, lymph node involvement, and hormone receptor sensitivity. Tumor subtypes such as tubular and mucinous carcinomas tend to have a lower metastatic potential and are associated with a better prognosis (Borst & Ingold, 1993). Invasive lobular carcinoma is more likely to metastasize to the gastrointestinal tract, whereas invasive ductal carcinoma more commonly spreads to the liver, lungs, and brain (Borst & Ingold, 1999).7 McLemore et al. (2005)8 reported that the colon and rectum are the most frequent sites for gastrointestinal metastases, followed by the stomach, small intestine, and esophagus. The presentation in this case, with initial symptoms of anemia and duodenal metastasis, is highly unusual for breast cancer.

The stomach is the most common site of metastatic breast carcinoma within the gastrointestinal (GI) tract (Chang et al., 1978; Joffe, 1975).9,10 The presenting symptoms often mimic those of peptic ulcer disease or gastritis (Easter et al., 1995).11 When breast cancer metastasizes to the stomach, it is essential to differentiate it from primary gastric carcinoma—a distinction that relies on radiologic, endoscopic, and histopathologic evaluations (Jones et al., 2007).12 Patients with gastrointestinal metastases may present with symptoms such as abdominal pain, nausea, vomiting, early satiety, weight loss, hematochezia, or rectal tenesmus.

The presentation of severe, symptomatic iron deficiency anemia is uncommon and not widely documented. Extensive gastrointestinal involvement may contribute to the severity of anemia and is often indicative of advanced disease (Khan et al., 2017).13 The presence of signet ring cells, commonly associated with gastric and other gastrointestinal adenocarcinomas, can further complicate the diagnostic process (Shakoor et al., 2014).14

There are a few reported cases involving simultaneous progression to both the stomach and colon, where severe anemia was the predominant presenting symptom (Pectasides et al., 2009; Signorelli et al., 2005; Villa Guzmán et al., 2017).15–17 Villa Guzmán et al. (2017)17 reported a case in which a patient presented with severe dyspeptic symptoms, including nausea and epigastric pain. Esophagogastroscopy revealed signs of malignancy, and biopsies from suspicious lesions confirmed metastasis from lobular breast carcinoma.

Treatment data for gastrointestinal metastases from breast cancer remains incomplete, with most cases managed using a combination of chemotherapy, surgery, endocrine therapy, and radiotherapy (Ambroggi et al., 2012).18 Surgical management of gastrointestinal metastases has not demonstrated a significant survival benefit, with some studies reporting no patients surviving beyond five years (Mourra et al., 2012).19 Diagnosing gastric metastasis from breast cancer is challenging due to its rarity and resemblance to primary GI tumors. Subtle findings, as seen in our case, underscore the need for thorough endoscopic and histological evaluation. Comparing gastric biopsy results with the original breast cancer histology is crucial for accurate diagnosis and guiding treatment.20

This underscores the importance of early diagnosis and treatment to alleviate symptoms and improve patient quality of life.

In this case, the absence of breast-related symptoms and withoutau family history of breast cancer made the diagnosis particularly challenging. Clinical consequences must be carefully considered when evaluating similar presentations. Patients with metastatic breast carcinoma who develop anemia should be thoroughly assessed for possible underlying causes, including gastrointestinal involvement. Additionally, chemotherapy or oral treatments may increase the risk of gastrointestinal bleeding and further complicate the clinical picture.

Given the patient’s critical condition, the clinical focus shifted to supportive care and goals-of-care discussions. This case highlights the importance of a comprehensive diagnostic approach in patients with complex presentations to ensure timely and appropriate management.

4. Conclusion

This case highlights the rare and complex presentation of metastatic breast cancer with gastrointestinal involvement. It underscores the importance of considering metastatic disease in patients presenting with unexplained anemia and gastrointestinal symptoms. Early and comprehensive evaluation—including imaging and histopathological analysis—is essential for accurate diagnosis and appropriate management.