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Colon cancer with gastric invasion mimicking gastric submucosal tumor
At the Focal Point
necrotic material on the top of the white slough, giving a “poached egg” appearance (A, B). The intervening mucosa was edematous and boggy. The remainder of the colon was normal as far as the rectum, where other poached egg lesions were seen. On the basis of our previous experience, an endoscopic diagnosis of intestinal amebiasis was made. Biopsy specimens were taken from the lesion, which revealed ulcerated mucosa with multiple trophozoites of Entamoeba histolytica (C). The patient was treated with intravenous metronidazole, and over the following 3 days his fever, diarrhea, and abdominal pain improved significantly. Four weeks later, US showed decreased thickening of the colon, and colonoscopy documented healing of
the previously seen ulcers. Now, 8 months after his initial presentation, the patient is asymptomatic. DISCLOSURE All authors disclosed no financial relationships relevant to this publication. Rajesh Upadhyay, MD, MRCP, Nitin Gupta, DM, Pratibha Gogia, DNB, Subhash Chandra, MD, Jaipur Golden Hospital, Delhi http://dx.doi.org/10.1016/j.gie.2012.03.171
Commentary Entamoeba histolytica is a parasite of global distribution, although most of its morbidity and mortality occurs in Central and South America, Africa, and the Indian subcontinent. It is estimated that E histolytica causes up to 50 million symptomatic cases and up to 100,000 deaths annually. The majority of the 500 million asymptomatic cyst passers are now believed to be infected with E dispar, a morphologically identical but nonpathogenic species of Entamoeba. Infection occurs after ingestion of the cysts in fecally contaminated food and water, after which, in the lumen of the small intestine, each cyst gives rise to 8 trophozoites, which then proceed to invade the colonic epithelium and, in some cases, then spread hematogenously to other organs, most notably the liver. The cecum and ascending colon are affected most commonly and inexplicably; downward invasion of the trophozoites usually is halted at the muscularis mucosae, thereafter spreading laterally and resulting in the so-called collar-button ulcers. Today it probably is better to use the more descriptive “clean-based, flask-shaped” to refer to these ulcers, as most people, myself included, have not had the experience of separately purchasing a button assembly to attach the separate collar to a shirt much as suspenders are attached to slacks, although in my imperfect analogy, the buttons are preattached to the trousers. The colonoscopic appearance of amebiasis is varied: edema, erythema, a myriad of ulcers resembling ulcerative colitis, punctuate ulcers separated by relatively normal mucosa, and now the “poached-egg” necroinflammatory lesion, which the authors tell me is “fairly predictive” of the diagnosis of amebiasis but not of prognostic significance. Of course, the perfect poached egg, cooked by sliding a fresh egg into simmering water, has solidified albumin and a runny yolk. Informed poachers know that the addition of an acidic liquid such as vinegar will help prevent dispersion of the egg white and make for a more attractive serving. With a pH of a saturated aqueous solution of metronidazole at 20°C being about 6.5, I wouldn’t recommend adding this antimicrobial to the simmering liquid to fortify the egg white. Added to the colon, however, it served a purpose that would be a culinary disaster, but that worked for the patient’s good, namely, to disperse forever not only the egg white, but also the yolk of this amebic poached egg. Lawrence J. Brandt, MD Associate Editor for Focal Points
Colon cancer with gastric invasion mimicking gastric submucosal tumor A 70-year-old woman presented to our outpatient department with several weeks of dull epigastric pain, belching, and early satiety. Physical examination revealed mild pallor and epigastric tenderness. Laboratory test results showed a leukocyte count of 14,400/mm3, hemoglobin of 10.7g/dL, and a positive fecal occult blood test. EGD disclosed an ovoid bulging mass at the posterior wall of the mid-gastric body (A, arrow) with intact overlying mucosa, a picture that suggested gastric submucosal tumor or external compression. CT showed a hypodense mass arising from the posterior greater curvature aspect of stomach (B, arrow), and 190 GASTROINTESTINAL ENDOSCOPY Volume 76, No. 1 : 2012
extending to the adjacent colonic wall. EUS demonstrated a 4.5-cm exophytic dumbbell-shaped mass arising from the propria muscularis (C, arrow) with hyperechoic components (C, arrowheads); it was diagnosed as a GI stromal tumor. Colonoscopy found a stricture near the splenic flexure; biopsy specimens were negative for malignancy. During laparotomy, a 5-cm ill-defined tumor was found at the distal transverse colon with gastric invasion and regional lymph node involvement. Left hemicolectomy with lymph node dissection was performed, and pathology showed the tumor to be adenocarcinoma. (D, arrow, H&E. orig. mag. ⫻10). The www.giejournal.org
At the Focal Point
final diagnosis was colon cancer with gastric invasion and lymph node involvement. She is currently receiving adjuvant chemotherapy and being followed in our oncology department. DISCLOSURE The authors disclosed no financial relationships relevant to this publication.
Pin-Chao Wang, MD, Chia-Chi Wang, MD, Ching-Sheng Hsu, MD, Division of Gastroenterology, Department of Internal Medicine, Chung-Tai Yue, MD, Department of Pathology, Jiann-Hwa Chen, MD, Division of Gastroenterology, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan http://dx.doi.org/doi:10.1016/j.gie.2012.02.017
Commentary I have said many times in the Focal Point series that the body is limited in the number of ways it can express disease and that disease too is limited in its expression. Here we can learn the “obtuse angle sign” in which tumors that arise from the submucosa and lesions growing from outside a hollow organ toward the lumen create an obtuse angle with the mucosa. Thus, any time it is suspected that a lesion arises from the submucosa, an external lesion must be excluded. Conversely, lesions that arise from the mucosa typically create an acute angle with the mucosa. In this case, colon cancer invaded the stomach and gave the www.giejournal.org
Volume 76, No. 1 : 2012 GASTROINTESTINAL ENDOSCOPY 191
At the Focal Point
EUS picture of a so-called dumbbell tumor, suggesting a GI stromal tumor; this appearance may also be seen with leiomyomas, or neural tumors such as schwannomas. The term “dumbbell” originated in the Tudor period (1485-1603) of English history, when athletes used hand-held church bells to develop their upper body. Because their use made a great deal of noise, the athletes would remove the clappers so they could practice quietly; hence the term “dumb,” as in “no sound,” before “bell.” It is rare for adenocarcinoma to have both an endophytic and exophytic growth pattern, which is what produces the dumbbell appearance, and explains the confusion in this case. FNA would have been helpful and would have resolved the initial mistaken identify, but would not have changed outcome. Lawrence J. Brandt, MD Associate Editor for Focal Points
GIE on Facebook GIE now has a Facebook page. Fans will receive news, updates, and links to author interviews, podcasts, articles, and tables of contents. Search on Facebook for “GIE: Gastrointestinal Endoscopy” and become a fan.
192 GASTROINTESTINAL ENDOSCOPY Volume 76, No. 1 : 2012
www.giejournal.org
necrotic material on the top of the white slough, giving a “poached egg” appearance (A, B). The intervening mucosa was edematous and boggy. The remainder of the colon was normal as far as the rectum, where other poached egg lesions were seen. On the basis of our previous experience, an endoscopic diagnosis of intestinal amebiasis was made. Biopsy specimens were taken from the lesion, which revealed ulcerated mucosa with multiple trophozoites of Entamoeba histolytica (C). The patient was treated with intravenous metronidazole, and over the following 3 days his fever, diarrhea, and abdominal pain improved significantly. Four weeks later, US showed decreased thickening of the colon, and colonoscopy documented healing of
the previously seen ulcers. Now, 8 months after his initial presentation, the patient is asymptomatic. DISCLOSURE All authors disclosed no financial relationships relevant to this publication. Rajesh Upadhyay, MD, MRCP, Nitin Gupta, DM, Pratibha Gogia, DNB, Subhash Chandra, MD, Jaipur Golden Hospital, Delhi http://dx.doi.org/10.1016/j.gie.2012.03.171
Commentary Entamoeba histolytica is a parasite of global distribution, although most of its morbidity and mortality occurs in Central and South America, Africa, and the Indian subcontinent. It is estimated that E histolytica causes up to 50 million symptomatic cases and up to 100,000 deaths annually. The majority of the 500 million asymptomatic cyst passers are now believed to be infected with E dispar, a morphologically identical but nonpathogenic species of Entamoeba. Infection occurs after ingestion of the cysts in fecally contaminated food and water, after which, in the lumen of the small intestine, each cyst gives rise to 8 trophozoites, which then proceed to invade the colonic epithelium and, in some cases, then spread hematogenously to other organs, most notably the liver. The cecum and ascending colon are affected most commonly and inexplicably; downward invasion of the trophozoites usually is halted at the muscularis mucosae, thereafter spreading laterally and resulting in the so-called collar-button ulcers. Today it probably is better to use the more descriptive “clean-based, flask-shaped” to refer to these ulcers, as most people, myself included, have not had the experience of separately purchasing a button assembly to attach the separate collar to a shirt much as suspenders are attached to slacks, although in my imperfect analogy, the buttons are preattached to the trousers. The colonoscopic appearance of amebiasis is varied: edema, erythema, a myriad of ulcers resembling ulcerative colitis, punctuate ulcers separated by relatively normal mucosa, and now the “poached-egg” necroinflammatory lesion, which the authors tell me is “fairly predictive” of the diagnosis of amebiasis but not of prognostic significance. Of course, the perfect poached egg, cooked by sliding a fresh egg into simmering water, has solidified albumin and a runny yolk. Informed poachers know that the addition of an acidic liquid such as vinegar will help prevent dispersion of the egg white and make for a more attractive serving. With a pH of a saturated aqueous solution of metronidazole at 20°C being about 6.5, I wouldn’t recommend adding this antimicrobial to the simmering liquid to fortify the egg white. Added to the colon, however, it served a purpose that would be a culinary disaster, but that worked for the patient’s good, namely, to disperse forever not only the egg white, but also the yolk of this amebic poached egg. Lawrence J. Brandt, MD Associate Editor for Focal Points
Colon cancer with gastric invasion mimicking gastric submucosal tumor A 70-year-old woman presented to our outpatient department with several weeks of dull epigastric pain, belching, and early satiety. Physical examination revealed mild pallor and epigastric tenderness. Laboratory test results showed a leukocyte count of 14,400/mm3, hemoglobin of 10.7g/dL, and a positive fecal occult blood test. EGD disclosed an ovoid bulging mass at the posterior wall of the mid-gastric body (A, arrow) with intact overlying mucosa, a picture that suggested gastric submucosal tumor or external compression. CT showed a hypodense mass arising from the posterior greater curvature aspect of stomach (B, arrow), and 190 GASTROINTESTINAL ENDOSCOPY Volume 76, No. 1 : 2012
extending to the adjacent colonic wall. EUS demonstrated a 4.5-cm exophytic dumbbell-shaped mass arising from the propria muscularis (C, arrow) with hyperechoic components (C, arrowheads); it was diagnosed as a GI stromal tumor. Colonoscopy found a stricture near the splenic flexure; biopsy specimens were negative for malignancy. During laparotomy, a 5-cm ill-defined tumor was found at the distal transverse colon with gastric invasion and regional lymph node involvement. Left hemicolectomy with lymph node dissection was performed, and pathology showed the tumor to be adenocarcinoma. (D, arrow, H&E. orig. mag. ⫻10). The www.giejournal.org
At the Focal Point
final diagnosis was colon cancer with gastric invasion and lymph node involvement. She is currently receiving adjuvant chemotherapy and being followed in our oncology department. DISCLOSURE The authors disclosed no financial relationships relevant to this publication.
Pin-Chao Wang, MD, Chia-Chi Wang, MD, Ching-Sheng Hsu, MD, Division of Gastroenterology, Department of Internal Medicine, Chung-Tai Yue, MD, Department of Pathology, Jiann-Hwa Chen, MD, Division of Gastroenterology, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan http://dx.doi.org/doi:10.1016/j.gie.2012.02.017
Commentary I have said many times in the Focal Point series that the body is limited in the number of ways it can express disease and that disease too is limited in its expression. Here we can learn the “obtuse angle sign” in which tumors that arise from the submucosa and lesions growing from outside a hollow organ toward the lumen create an obtuse angle with the mucosa. Thus, any time it is suspected that a lesion arises from the submucosa, an external lesion must be excluded. Conversely, lesions that arise from the mucosa typically create an acute angle with the mucosa. In this case, colon cancer invaded the stomach and gave the www.giejournal.org
Volume 76, No. 1 : 2012 GASTROINTESTINAL ENDOSCOPY 191
At the Focal Point
EUS picture of a so-called dumbbell tumor, suggesting a GI stromal tumor; this appearance may also be seen with leiomyomas, or neural tumors such as schwannomas. The term “dumbbell” originated in the Tudor period (1485-1603) of English history, when athletes used hand-held church bells to develop their upper body. Because their use made a great deal of noise, the athletes would remove the clappers so they could practice quietly; hence the term “dumb,” as in “no sound,” before “bell.” It is rare for adenocarcinoma to have both an endophytic and exophytic growth pattern, which is what produces the dumbbell appearance, and explains the confusion in this case. FNA would have been helpful and would have resolved the initial mistaken identify, but would not have changed outcome. Lawrence J. Brandt, MD Associate Editor for Focal Points
GIE on Facebook GIE now has a Facebook page. Fans will receive news, updates, and links to author interviews, podcasts, articles, and tables of contents. Search on Facebook for “GIE: Gastrointestinal Endoscopy” and become a fan.
192 GASTROINTESTINAL ENDOSCOPY Volume 76, No. 1 : 2012
www.giejournal.org