Introduction

Approximately 50% of lung cancer patients have distant metastases at diagnosis. The most common organ metastases are the brain, liver, bones and adrenals. Approximately one third of lung cancer patients have symptoms due to distant metastases. Intestinal metastasis of lung cancer is very rare and usually asymptomatic (1,2). Most of the lung cancers causing intestinal metastasis are squamous cell carcinomas according to literature and it is followed by large cell lung cancer. In 70% of cases, extra-intestinal metastases are seen along with small intestine. Generally, bowel perforation and obstruction of the cases can be observed.

Case

A 65-year-old male patient had been referred to a peripheral hospital because of abdominal pain. A mass lesion located on the apex of the right lung had been detected on his chest X-ray (Figure 1). Afterwards, further investigations had been done accordingly and many other widespread lesions had been observed located in brain and abdominal cavity which all were compatible with metastasis (Figure 2,3). The bronchoscopy procedure had been consistent with primary lung tumor. The biopsy confirmed adenocarcinoma. Radiotherapy along with anti-edema treatment (Dexamethasone 4*4 mg, Levetirasetam 2*500) had been given for brain metastases. His chemotherapy had been postponed since he had had pneumonia after bronchoscopy.

Later on, he was admitted to our emergency surgery department with the complaint of abdominal pain prolonging for 3-4 days which had aggravated for the last day. Physical examination revealed acute abdomen mimicking symptoms like widespread tenderness, defense and rebound during palpation. Plain graph showed free air under the right hemi-diaphragm. Oral/iv contrast-enhanced thoracic and abdominal computerized tomography (CT) revealed an image of pneumoperitoneum located mostly around anterior surface of the liver. No contrast extravasation was observed. Heterogenic mass lesion having an approximate diameter of 7*6 cm was detected on apical segment of the right lung (Figure 4).

Necessary blood samples were taken during admission, and laboratory values were as follows; Hb/Htc: 9.4/28.9 White blood cell: 7000 C-reactive protein: 80. A detailed informed consent had been taken from the patient and his relatives after giving information about the risks and complications. Later on, he underwent operation due to pre-op diagnosis of hollow organ perforation.

After a laparoscopic exploration, the operation was converted to laparotomy due to dens adhesions which prevented adequate exposure. Abdominal exploration revealed a micro-perforation located on the anti-mesenteric site of the small bowel which was 190 cm distal to Treitz ligament. Multiple implants were observed along the serosa of the small bowel. All small bowel segments beginning from Treitz ligament till the ileocecal valve were explored carefully. Perforated small bowel segment was resected, and functional end-to-end anastomosis with stapler was performed accordingly. Afterwards, the patient was taken to intensive care unit for post-operative follow-up.

The patient was taken to the ward on the following day. Oral intake was initiated on the second day of operation. The patient did not have any problems during the hospitalization period and was discharged uneventfully. The patient was referred to the oncology department for systemic chemotherapy. He died 4 months after the surgery because of terminal disease. Pathological findings were consistent with adenocarcinoma metastasis of lung cancer (Figure 5,6).

Discussion

The most common sites for distant metastasis of lung cancer are the lymph nodes, liver, adrenal glands, skeletal system, and brain respectively. Gastrointestinal metastases are very rare (3,4,5,6). It has been reported in some autopsy studies that it has a prevalence range between 4.7% and 14% (7,8). In the present study, we discussed the clinical course of an adult male patient having small bowel perforation due to metastasis originated from a lung cancer. According to our research in recent literature, about 1/3 of the intestinal metastases originated from lung cancers are asymptomatic, and the diagnosis is usually made following the autopsy. Tumor necrosis induced by chemotherapy has also been claimed to have led to perforation. Gastrointestinal system metastasis of lung tumors occur via hematogenic and/or lymphatic route. Most common symptoms are abdominal pain, nausea/vomiting, anemia and weight loss (9-11). These findings mostly occur after the diagnosis of the primary disease and, sometimes, are seen before or simultaneously with the diagnosis of the primary disease as in our case. Yang et al. (12) scanned 399 lung carcinoma cases between 2003 and 2005, and found six (1.77%) cases who had symptomatic gastrointestinal system metastasis. The diagnosis was made by using gastroscopy for three patients who had gastric metastasis and by colonoscopy for one patient (cecum involvement), and two patients underwent operation due to small bowel perforation and intussusception respectively (13,14). Histological subtypes of bronchogenic carcinomas leading to metastasis differ among studies regarding theirs frequencies. In one study, it was observed that large cell carcinoma of lung metastasized more than the others, whereas in other studies, squamous subtype was to be found more aggressive regarding metastasis. Yang et al. (12) reported squamous cell lung carcinoma to be the most common type of lung cancer having distant metastasis (15-17).

It is difficult to diagnose intestinal metastasis at an early stage before serious complications occur (18). Conventional CT, which is mostly the preferred imaging modaliy, has a low sensitivity to detect small intestine metastases. In some instances, certain indirect findings such as intestinal intussusception are more informative.

No significant pathology was detected after the evaluations done by the peripheral center. The patient was referred to our institute with the persistent complaint of abdominal pain later on. Pathological flourodeoxyglucose uptake in the region fitting ileum on positron emission tomography was helpful reaching the diagnosis. It was not clear whether the lesion was a primary tumor of the gastrointestinal tract or a metastatic lesion (19). Diagnosis was established later on by immunohistochemical examination of the specimen.

Conclusion

The disease has a low rate of overall survey since it has an insidious clinical course despite distant metastasis mostly. Gastrointestinal metastases are very rare. It is difficult to diagnose intestinal metastasis at an early stage before complications occur. If the diagnosis is established at an early period, the life expectancy may be prolonged.

Informed consent: Written informed consent was obtained from the patient.

Peer-review: Externally peer-reviewed.

Author Contributions: Surgical and Medical Practices - B.M., İ.C.S., E.E.; Concept - E.A., R.E.S.; Design - E.A., M.İ., R.E.S.; Data Collection and/or Processing - E.A.; Analysis and/ or Interpretation - E.A.; Literature Search - E.A.; Writing Manuscript - E.A.

Conflict of interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study received no financial support.