Low digestive haemorrhage due to giant-cell lung carcinoma metastasis

Lung cancer is the leading cause of cancer death in the world, with a 5-year survival rate of 10–20%. Nearly 50% of patients have metastatic disease at diagnosis, and a 5-year survival rate of less than 5%.¹ Giant cell carcinoma is a rare and poorly-differentiated variant that accounts for 0.1−0.4%² of cases of lung cancer.

Primary lung cancer usually metastasises to the brain, liver, adrenal glands, lymph nodes and bones.¹ The gastrointestinal tract is an atypical site of spread (0.5–1.3%), although autopsy studies have found that it could be underdiagnosed (4.7–14%),¹ due to spread through the blood and lymph nodes.

We present the case of an 81-year-old man, a former smoker who quit smoking 12 years earlier, with a history of left lower lobectomy plus lymphadenectomy for giant cell carcinoma in April 2018 (pT1bN0 with clear resection margins), with no remote disease observed in studies of spread (M0). During follow-up, no signs suggestive of relapse were seen, nor were there any abnormalities in tumour markers. The only finding worthy of note was a gradual development of anaemia.

The patient was admitted in May 2019, having been transferred from another hospital, for signs and symptoms of low gastrointestinal bleeding and several syncopal episodes, with a haemoglobin level as low as 6.39 mg/dl. He did not present any abdominal signs or symptoms, and examination revealed no findings of interest. The patient underwent a colonoscopy and a gastroscopy, which showed no lesions, and the study was completed with a capsule endoscopy which identified two small vascular lesions of an angiodysplastic nature: one in the proximal duodenum and the other in the proximal-medial jejunum. With these findings, an endoscopy was performed for purposes of haemostasis of these lesions. Given the persistence of the patient's signs and symptoms, a decision was made to perform thoracoabdominal computed tomography. This found a hypervascular mass measuring 25 mm in the mesentery of a loop of terminal ileum infiltration towards the intestinal lumen. In view of the findings of the computed tomography scan, a decision was made to perform an emergency exploratory laparoscopy. This revealed a hard, umbilicated endoluminal tumour measuring 7 cm × 7 cm in the proximal ileum (Fig. 1). A total of 20 cm of proximal ileum were then resected with end-to-end manual anastomosis. The patient had no complications in the postoperative period and was discharged on day 7 after the procedure.

Figure 1.

Macroscopic image of the surgical specimen: a hard, umbilicated endoluminal tumour measuring around 7 cm × 7 cm in the proximal ileum.

The pathology study identified the tumour as giant cell carcinoma metastasis (positive for vimentin, mixed CK, CK7 and TTF, with no EGFR, BRAF or K-RAS mutation detected) consistent with metastatic lung cancer relapse. The patient was referred back to his oncologist, who started chemotherapy with paclitaxel and carboplatin. Radiological follow-up identified multiple bone lesions consistent with bone M1 lesions.

As already mentioned, metastasis of lung cancer to the gastrointestinal tract is uncommon; the main site of spread of this type of cancer is the small intestine (8.1%), followed by the stomach (5.1%) and the large intestine (4.1%).¹ The subtypes that most often metastasise to the small intestine are squamous cell, large cell and pleomorphic (which includes the giant cell subtype).

It is usually diagnosed by X-ray, ultrasound or computed tomography (diagnostic method of choice). Computed tomography angiography and capsule endoscopy are also useful in cases of gastrointestinal haemorrhage with no obstruction.^3,4 The differential diagnosis between a primary and a metastatic tumour can be difficult. Hence, immunohistochemistry plays a crucial role.³

Treatment must be focused in the context of metastatic lung cancer, although surgical resection of the bowel may be required in case of perforation, bowel obstruction or bleeding. Chemotherapy, as a neoadjuvant treatment, depends on the histopathology of the tumour and the condition of the patient,³ as treatment in itself may increase the risk of perforation or bleeding.⁵

Despite surgical resection of intestinal metastases, around 50–60% of patients experience metastatic relapse, and one- and three-year survival rates are 44.4% and 33.3%, respectively.⁵

In conclusion, in patients with a history of lung cancer, the possibility of metastasis to the small bowel in a context of bleeding, obstruction or perforation must be included in the diagnostic algorithm.

In these cases, surgical resection is an option that contributes to solving the urgent condition as well as establishing a diagnosis and planning an oncological treatment strategy.