Gastrointestinal bleeding due to small bowel metastasis from lung adenocarcinoma: A case report

Abstract

BACKGROUND

Lung cancer is the most prevalent malignant tumor in human body, and is characterized by a high level of malignancy. The most common metastatic sites include the liver, bone, brain, and adrenal gland, while lung cancer resulting in gastrointestinal tract metastasis is uncommon.

CASE SUMMARY

A 74-years-old man with lung cancer was hospitalized owing to blood in the stool, The cause was identified as metastasis to the small intestine, and the patient subsequently underwent radical resection of the small intestine tumor. Currently, the overall condition of the patient is good, and undergoing combined chemotherapy.

CONCLUSION

Early intervention in patients with metastatic tumors can significantly improve prognosis.

Key Words: Lung adenocarcinoma; Metastatic tumors; Small intestinal tumor; Gastrointestinal bleeding; Case report

Core Tip: This article introduces a case of lung cancer with small bowel metastasis and gastrointestinal bleeding, which is relatively rare compared with other sites, and the patient underwent laparoscopic radical resection of small bowel cancer, and the long-term prognosis still needs to be observed and followed. We look forward to providing a helpful clinical experience based on this case, and there is an urgent need to record more cases to support more advanced research efforts aimed at improving the detection rate of these patients and ultimately improving the quality of life and survival of patients.

INTRODUCTION

Lung cancer is the most prevalent malignant tumor in the human body, characterized by a high degree of malignancy. The most common sites of metastasis are including the liver, bone, brain, and adrenal glands. In contrast, metastasis of lung cancer resulting in the digestive tract is relatively uncommon, and limited research is found on this topic. Therefore, this study aims to investigate a case of small bowel metastasis from lung cancer that caused gastrointestinal bleeding, offering a potential diagnostic and therapeutic approach for managing with gastrointestinal bleeding as the primary symptom.

CASE PRESENTATION

Chief complaints

This patient was admitted to the hospital with black stools for 5 hours.

History of present illness

The patient (a 74-year-old elderly man) was first visited our hospital in 2019 after a ground-glass nodule was discovered in the upper lobe of the right lung. On July 18, 2019, he underwent thoracoscopic wedge resection of the right upper and lower lung nodule under general anesthesia, following the ruling out of any contraindications to surgery. Postoperative pathology revealed invasive adenocarcinoma (nodule in the upper lobe of the right lung), with two masses that did not invade the lung membranes, and no cancerous involvement of the anastomotic margins. The (nodule in the lower lobe of the right lung) showed microinvasive adenocarcinoma without invasion of the lung membranes, and no cancer involvement at the anastomotic end margins. The patients underwent regular follow-up chest computed tomography (CT). On July 25, 2023, the patient was hospitalized with a history of “4 years after surgery for right lung cancer, and the right lung nodule was found to have increased in size over the past 3 days compared with the previous one”. Upon admission, the patient underwent a complete examination of blood, which revealed no significant abnormalities. After discussing with the family, the patient chose to undergo CT-guided percutaneous lung nodule aspiration biopsy and thermal ablation under local anesthesia on July 28, 2023 and August 8, 2023, respectively, following these procedures, the patient underwent regular follow-up chest CT scans of the upper and middle lobe lesions in the right lung, alongside thermal ablation treatment to reduce the lesions compared to those of the previous scan.

On January 9, 2024, the patient was admitted to the emergency department of our hospital 5 hours ago for acute upper gastrointestinal hemorrhage after having 3 black stools, large in total amount, without vomiting blood, accompanied by obvious panic and weakness, without fainting, and without abdominal pain and distension.

History of past illness

Thirty years history of hypertension, systolic blood pressure up to 200 mmHg, taking 2 tablets of compound reserpine 1 day, 1 tablet of nifedipine extended-release tablets 1 day, 2 tablets of captopril 1 day, systolic blood pressure under control at 150 mmHg. Seven years history of carotid stenosis on the left side and cerebral stenosis. Four years after surgery for right lung cancer. Right lung cancer 4 years after surgery. Five months after thermal ablation of right lung tumor. No history of coronary heart disease or diabetes mellitus; no history of hepatitis, tuberculosis or other infectious diseases or close contact with them; no history of blood transfusion; allergic to penicillin and streptomycin, no history of food or other drug allergies; history of vaccinations unknown.

Personal and family history

No obvious abnormalities were found.

Laboratory examinations

On January 9, 2024, the patient presented with black stool and was urgently tested, revealing a hemoglobin level of 58 g/L. Given the active bleeding, the patient was admitted to the gastroenterology department with a history of “black stool for 5 hours”. Treatment included blood transfusion, fluid supplementation, hemostasis, and acidic gastric protection, among other interventions.

Imaging examinations

The patient underwent a CT examination of the chest and abdomen, which revealed localized thickening of the small bowel wall in the left lower abdomen with multiple surrounding lymph nodes, suggesting small bowel occupancy with peripheral lymph node metastasis. Oral small bowel imaging showed gastritis, while no significant abnormalities were found in the jejunum ileum and ileocecum region. Additionally, double-balloon enteroscopy revealed small bowel occupation and bleeding; along with submucosal elevation, that may represent lipoma. The nature of esophageal lesions; non-atrophic gastritis (Figure 1). Immunohistochemistry results showed the following: P53 (wild type expression), Ki67 (basal high expression), and jejunum checked for carcinoma, the findings included: SMARCA4 (deletion), CK7 (+), TTF-1 (-), Napsin A (-), SPA (-), SP-B (-), CK20 (-), Villin (focal +), CDX-2 (-), SATB2 (individually weakly plus), CK5/6 (-), P40 (-), and Ki67 (+ 65%; Figure 2). The patient was subsequently transferred for emergency abdominal surgery. Upon evaluation, the patient underwent laparoscopic radical resection for small bowel cancer on January 20, 2024. During surgery, a small bowel tumor was found 200 cm from the beginning of the jejunum, with the distal lumen of the small bowel and lumen of the colon being were covered with black blood, suggesting gastrointestinal hemorrhage owing to small bowel cancer. Further immunohistochemistry of the tumor cells revealed CK (+), CK 7 (+), TTF1 (-) Napsin A (-), P40 (-), P63 (-), INI1 (+), CK20 (-), Villin (-), Syn (-), CgA (-), CD56 (-), SALL4 (-), CD34 (-), SATB2 (weakly +), CDX-2 (-), and Ki67 (hot spot area +) about 65%; special staining result: PAS (+); The pathologic diagnosis was poorly differentiated adenocarcinoma with a bulging mass invading the subplasma membrane. No cancer involvement was seen at the cut margins of both ends of the specimen. Metastatic carcinoma was identified in the peristomal lymph nodes (2/17), which, along with the history of the patient, was consistent with a pulmonary origin.

Figure 1 Oral small bowel imaging. A-C: Visible elevation of the small intestine and bowel occupation with hemorrhagic manifestations.

Figure 2 Immunohistochemistry results. A: CK7 is a key component of cytokeratin, and the positivity is usually indicative of a high likelihood of adenocarcinoma. In this patient, CK7 was distinctly positive in a localized area; B: The primary site of Ki67 positivity is located in the nucleus. Ki67 is a marker of cell proliferation and primarily reflects the proliferative state of the cell. The immunohistochemistry result of the small bowel microscopy pathology of this patient shows a Ki67 index of 65%, reflecting a high proliferative activity). CA weakly positive expression of SATB2 is observed in the individual; D: SMARCA4-deficient undifferentiated carcinomas are commonly found in multiple sites, most especially in the lungs and rarely in the gastrointestinal tract. Based on a 2023 lung tissue biopsy that also demonstrated SMARCA4 deletion, intestinal metastases from lung cancer cannot be excluded from this intestinal tissue; E: Weak, localized positivity for Villin was observed.

FINAL DIAGNOSIS

Following the surgical intervention, the patient no longer experienced black stool, and the postoperative diagnosis included: (1) Postoperative lung cancer with small intestinal tumor metastasis; (2) Acute upper gastrointestinal hemorrhage; (3) Postoperative right lung cancer; and (4) Post thermal ablation of the right lung tumor.

TREATMENT

The patient underwent laparoscopic radical resection for small bowel cancer on January 20, 2024.

OUTCOME AND FOLLOW-UP

A literature review revealed that > 50% of patients with small intestinal metastases from lung cancer died within 3 months, while < 10% survived beyond 1 year[1]. Tracking and follow-up revealed that the patient discontinued docetaxel/carboplatin and tirilizumab combination chemotherapy after surgery, during which no adverse reactions, such as small intestinal hemorrhage, perforation, or obstruction, were observed. As a non-traditional PD-1 inhibitor, tirilizumab avoids T-cell reduction while maintaining anti-tumor efficacy. The current general condition of the patient is good, further demonstrating that early detection and therapeutic intervention can improve the survival rate of such cases.

DISCUSSION

Diagnostic difficulties

(1) Digestive tract metastasis caused by lung cancer is primarily categorized into symptomatic and asymptomatic digestive tract metastasis. Symptomatic digestive tract metastasis can be detected clinically. In contrast, asymptomatic digestive tract metastasis, is usually identified more frequently during autopsy than that observed in the clinically, making it challenging to detect and diagnose; (2) Since many gastrointestinal symptoms in patients, such as nausea, vomiting, and abdominal distension, are non-specific and may be mistaken for normal gastrointestinal reactions during lung cancer treatment, this makes diagnosis challenging owing to the atypical symptoms; and (3) Owing to the lack of specific tests for digestive tract metastasis caused by lung cancer, it can be more difficult to detect small bowel tumors using standard abdominal CT scans. Some studies have revealed that new technologies, such as positron emission tomography-CT, capsule endoscopy, and double-balloon enteroscopy, show good prospects for detecting small bowel lesions. However, it remains challenging to diagnose without specificity in ancillary tests.

Diagnostic thinking of this patient

The patient initially underwent abdominal CT scanning, which revealed localized thickening of the small intestine wall. While these findings could be considered as a placeholder, they did not clarify the nature of the lesion of the patient. Additionally, the small bowel imaging method provides limited results and fails to identify the cause of the gastrointestinal bleeding of the patients. The primary factors that contributed to clarifying the diagnosis included: (1) The small bowel colonoscopy of the patient, which revealed a small bowel occupation and bleeding, providing a crucial explanation to identify the primary cause of the bloody stools of the patients; and (2) After evaluating the small bowel occupation and bleeding of the patient, they were transferred to gastrointestinal surgery. During the operation, a black, bloody stool was observed covering the distal intestinal lumen of the small bowel and the colon lumen. Intraoperative pathological examination and immunohistochemistry were performed, confirming that the poorly differentiated carcinoma of the small bowel of the patient originated from lung tumor metastasis. Consequently, the postoperative diagnosis was lung cancer with metastasis of the small bowel tumor In this case, a review of the literature highlighted four immunohistochemistry results, such as CK7 (+), CK20 (-), TTF -1, and CDX2, which could help the patient determine if the small bowel tumor was primary or secondary, with the results showing CK7 (+), CK20 (-), CDX2 (-), and TTF1(-), which strongly supported lung cancer as the primary source of the tumor[2].

Treatment

Studies have shown that patients with gastrointestinal metastases usually indicate advanced stages of the tumor. Surgical intervention is typically required for complications such as gastrointestinal perforation and gastrointestinal hemorrhage. However, early detection of gastrointestinal metastases in patients with lung cancer, along with timely surgery, can help alleviate the life-threatening symptoms and improve long-term survival in patients with only isolated gastrointestinal metastases. This patient has undergone radical resection of small bowel cancer and currently exhibits no further black stools. However, the long-term prognosis requires continued observation and follow-up. Additionally, the optimal timing and treatment strategies for surgical treatment of lung cancer metastases in the small bowel require further clinical research.

CONCLUSION

This case provides several insights: (1) For patients with lung cancer, small intestinal metastasis is rare; however, with advancements in diagnostic and treatment technologies, reports of such cases are gradually increasing. When gastrointestinal symptoms occur, it is important to consider not only the adverse reaction from the treatment of the primary tumor but also the gastrointestinal metastasis, which is essential for the prognosis of the patient; (2) When patients is present with gastrointestinal symptoms, it is crucial to perform endoscopy as early as possible to clarify the diagnosis of the patients if conditions permit; (3) When small bowel tumors are detected, it is important to determine if they are primary or secondary to other parts of the body. This requires further identification through pathology and immunohistochemistry; and (4) For patients with small bowel metastasis owing to lung cancer, surgery can alleviate the local symptoms caused by the metastatic tumors. However, the long-term effects require further follow-up.