Synchronous multifocal early gastric cancers and rectal adenocarcinoma: Lesson learnt from image‐enhanced endoscopy

Abstract

Early detection of cancer leads to potentially curative treatment and improved overall survival. The long-term outcome of patients with early gastric cancer (EGC) is better than that of the patients with a later stage of disease, with 5-year survival rates being over 95%. Multifocal EGC are not commonly diagnosed. However, advances in endoscopic imaging have made the early and improved recognition of EGC possible. Here, we present a rare scenario where a patient with rectal cancer was diagnosed with synchronous multifocal gastric cancer. The added value of image-enhanced endoscopy using autofluorescence imaging (AFI) and narrow-band imaging (NBI) with optical magnification in the detection and differentiation of EGC is demonstrated and discussed. A 74-year-old Chinese woman with underlying ulcerative colitis was undergoing palliative radiotherapy for a recently diagnosed rectal adenocarcinoma. Serious comorbidities of recent basal ganglia hemorrhage and cervical myelopathy, in addition to her advanced age, prevented her from undergoing curative surgery. She underwent an upper gastrointestinal (UGI) endoscopy to evaluate a fall in her hemoglobin level and suspected malena. Conventional white light endoscopy using a standard gastroscope (GIF Q160, Olympus, Tokyo, Japan) revealed a small, slightly elevated antral lesion at the anterior wall measuring approximately 10 mm in diameter (Fig. 1). This lesion was biopsied and histology revealed presence of dysplastic cells suspicious, but not definitive of malignancy. A repeat UGI endoscopy was then performed using a high definition gastroscope with AFI, NBI and optical magnification functions (GIF FQ260Z, Olympus, Tokyo, Japan). In addition to the previously detected lesion that was now clearly evident (Fig. 2), a second lesion was detected at the lesser curvature (measuring approximately 15 mm by 25 mm) (Fig. 3). Both lesions were of type 0–IIa (superficial, elevated type) morphology (Japanese Research Society for Gastric Cancer Classification). With AFI it appeared as a purplish plaque against a green background (Fig. 4). NBI with optical magnification demonstrated the presence of distorted mucosal pit pattern and abnormal capillaries (a corkscrew microvascular pattern) (Fig. 5). Targeted biopsies at the sites of distorted pit and microvascular patterns confirmed the diagnosis of adenocarcinoma. Conventional white light endoscopic image of the antral lesion. High definition white light endoscopic image of the antral lesion. High definition white light endoscopic image of a second lesion at the gastric lesser curvature. Autofluorescence image of the gastric lesser curve lesion. Narrow-band imaging with optical magnification demonstrated the presence of distorted mucosal pit pattern and corkscrew microvascular pattern. EGC is defined as a carcinoma of the stomach that is confined to the mucosa and submucosa of the gastric wall, regardless of lymph node involvement.1 Lesions less than 3 cm in size, with differentiated histology and the absence of lymphovascular invasion have a low risk of lymph node metastasis. Endoscopic resection would thus be a suitable choice of treatment. Multifocal EGC may occur in up to 15% of patients with gastric carcinomas.2,3 Risk factors for multifocal EGC include elder age, male gender, gastric atrophy and severe intestinal metaplasia. Interestingly it has been reported that patients with multiple gastric cancers have a significantly higher frequency of synchronous tumors than patients with single gastric cancer (8.2% vs 3.5%). The most common synchronous tumor was colorectal cancer, as in this case. About 4.5% of patients with multifocal EGC may also have preceding or synchronous primary malignancies arising from the lung, esophagus and liver.4–6 However, during conventional white light endoscopy the endoscopic appearance of EGC may be subtle and easily missed or result in sampling errors and a false negative histology. One study found that an endoscopy missed additional lesions in 27.5% of patients and that small lesion size was the most important factor for failure to detect these lesions. The mean size of the missed lesions was 1.57 cm.7 By producing real-time false-color images based on tissue autofluorescence from endogenous fluorophores emitted by excitation light, AFI may detect early gastrointestinal cancers that are not detected by white light endoscopy.8 AFI, however, is limited by a high false positive rate as areas of inflammation appear abnormal. NBI with optical magnification allows the characterization of the mucosal pit and microvascular patterns.9 In EGC the patterns will be distorted10 and this facilitates a targeted biopsy, thus reducing the likelihood of sampling errors. Yasumasa et al. reported a diagnostic accuracy for NBI that is significantly higher than white light imaging (79% vs 44%).11 In our patient a second lesion was found during repeat endoscopy using a high definition AFI/NBI video endoscope and EGC was subsequently diagnosed in both lesions. To conclude, the use of high definition AFI/NBI video endoscopy improves the detection and differentiation of EGC, leading to the potential for complete endoscopic resection with less surgical morbidity and improved overall survival.