CLINICAL CHALLENGES AND IMAGES IN GI A Rare Gastric Tumor in a Young Woman Biyan Lu,1,2,3,4 Weibiao Ye,5 and Huanliang Liu1,2,3 1
Guangdong Institute of Gastroenterology, the Sixth Affiliated Hospital, Guangzhou; 2Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Guangzhou; 3Institute of Human Virology and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou; 4Dongguan Health School, Dongguan; 5Dongguan Hospital of Southern Medical University, Dongguan, China
Question: A 26-year-old woman was admitted with a 3-week history of progressive abdominal distension, nausea, vomiting, and tarry stool. She denied any significant past medical history or family history. Physical examination revealed mild epigastric tenderness. Laboratory tests were unremarkable except for a moderate normocytic anemia (hemoglobin, 72 g/L). Barium-meal radiographs in her local community hospital showed a large, semicircular filling defect in the antrum of the stomach (Figure A). Upper gastrointestinal endoscopy revealed a nodular lesion (Figure B). Subsequent CT depicted a relatively well-defined, low-density mass protruding into the gastric lumen (Figure C). What is the most likely diagnosis? Look on page 295 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.
Acknowledgments Address correspondence to: Huanliang Liu, Professor, Guangdong Institute of Gastroenterology and the Sixth Affiliated Hospital, Sun Yat-sen University, 22 Yuancun Er Heng Road, Guangzhou, Guangdong 510655, China. e-mail: [email protected]. Conflicts of interest The authors disclose no conflicts. Funding This study was supported by Guangdong Provincial Department of Science and Technology (2012B050500004) ; Guangdong Innovative Research Team Program (2009010058); National Key Clinical Discipline, National Natural Science Foundation of China (81301978); Overseas Excellent Professor Project, Ministry of Education, China. © 2015 by the AGA Institute 0016-5085/$36.00 http://dx.doi.org/10.1053/j.gastro.2015.03.050
Gastroenterology 2015;149:294–295
CLINICAL CHALLENGES AND IMAGES IN GI Answer to Image 2 (page 294): Gastric Plexiform Angiomyxoid Myofibroblastic Tumor The tumor and the affected segment of the stomach were removed through distal gastrectomy. A mucoid, nodular, exophytic tumor was found in the antrum. Pathologic examination displayed ovoid or spindled-shaped cell proliferation in a myxoid or fibromyxoid matrix with a plexiform intramural growth pattern (Figure D). Tumor cells were immunohistochemically positive for smooth muscle actin (SMA) and Vim, but negative for CD34, c-Kit, and Dog-1 (Figure E). Gastric plexiform angiomyxoid myofibroblastic tumor (PAMT) was diagnosed. PAMT is a novel rare entity of gastric mesenchymal tumors, first described in 2007 by Takahashi et al.1 The tumor occurs almost exclusively in the gastric antrum and exhibits unique histologic features, including a plexiform intramural growth pattern of ovoid or spindle cells in the myxoid extracellular matrix. The tumor cells have limited cytologic atypia and exhibit myofibroblastic differentiation with expression of SMA. As a member of gastric non-gastrointestinal stromal mesenchymal tumors, PAMT is exceedingly rare, with only about 39 isolated cases reported in the English-language medical literature.2 According to previous reports, PAMT can occur at any age (range, 7–75 years) and has a roughly equal gender distribution. Although extragastric extension and vascular invasion could sometimes be observed, there have been no reported cases of local recurrence or distant metastases after resection.3 PAMT is predicted to exhibit benign biological behavior. Therefore, operative resection with a margin of normal tissue is the primary treatment of choice.
References 1. 2. 3.
Takahashi Y, Shimizu S, Ishida T, et al. Plexiform angiomyxoid myofibroblastic tumor of the stomach. Am J Surg Pathol 2007;31:724–728. Duckworth LV, Gonzalez RS, Martelli M, et al. Plexiform fibromyxoma: report of two pediatric cases and review of the literature. Pediatr Dev Pathol 2014;17:21–27. Miettinen M, Makhlouf HR, Sobin LH, et al. Plexiform fibromyxoma: a distinctive benign gastric antral neoplasm not to be confused with a myxoid GIST. Am J Surg Pathol 2009;33:1624–1632.
For submission instructions, please see the Gastroenterology web site (www.gastrojournal.org).
295
Guangdong Institute of Gastroenterology, the Sixth Affiliated Hospital, Guangzhou; 2Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Guangzhou; 3Institute of Human Virology and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou; 4Dongguan Health School, Dongguan; 5Dongguan Hospital of Southern Medical University, Dongguan, China
Question: A 26-year-old woman was admitted with a 3-week history of progressive abdominal distension, nausea, vomiting, and tarry stool. She denied any significant past medical history or family history. Physical examination revealed mild epigastric tenderness. Laboratory tests were unremarkable except for a moderate normocytic anemia (hemoglobin, 72 g/L). Barium-meal radiographs in her local community hospital showed a large, semicircular filling defect in the antrum of the stomach (Figure A). Upper gastrointestinal endoscopy revealed a nodular lesion (Figure B). Subsequent CT depicted a relatively well-defined, low-density mass protruding into the gastric lumen (Figure C). What is the most likely diagnosis? Look on page 295 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.
Acknowledgments Address correspondence to: Huanliang Liu, Professor, Guangdong Institute of Gastroenterology and the Sixth Affiliated Hospital, Sun Yat-sen University, 22 Yuancun Er Heng Road, Guangzhou, Guangdong 510655, China. e-mail: [email protected]. Conflicts of interest The authors disclose no conflicts. Funding This study was supported by Guangdong Provincial Department of Science and Technology (2012B050500004) ; Guangdong Innovative Research Team Program (2009010058); National Key Clinical Discipline, National Natural Science Foundation of China (81301978); Overseas Excellent Professor Project, Ministry of Education, China. © 2015 by the AGA Institute 0016-5085/$36.00 http://dx.doi.org/10.1053/j.gastro.2015.03.050
Gastroenterology 2015;149:294–295
CLINICAL CHALLENGES AND IMAGES IN GI Answer to Image 2 (page 294): Gastric Plexiform Angiomyxoid Myofibroblastic Tumor The tumor and the affected segment of the stomach were removed through distal gastrectomy. A mucoid, nodular, exophytic tumor was found in the antrum. Pathologic examination displayed ovoid or spindled-shaped cell proliferation in a myxoid or fibromyxoid matrix with a plexiform intramural growth pattern (Figure D). Tumor cells were immunohistochemically positive for smooth muscle actin (SMA) and Vim, but negative for CD34, c-Kit, and Dog-1 (Figure E). Gastric plexiform angiomyxoid myofibroblastic tumor (PAMT) was diagnosed. PAMT is a novel rare entity of gastric mesenchymal tumors, first described in 2007 by Takahashi et al.1 The tumor occurs almost exclusively in the gastric antrum and exhibits unique histologic features, including a plexiform intramural growth pattern of ovoid or spindle cells in the myxoid extracellular matrix. The tumor cells have limited cytologic atypia and exhibit myofibroblastic differentiation with expression of SMA. As a member of gastric non-gastrointestinal stromal mesenchymal tumors, PAMT is exceedingly rare, with only about 39 isolated cases reported in the English-language medical literature.2 According to previous reports, PAMT can occur at any age (range, 7–75 years) and has a roughly equal gender distribution. Although extragastric extension and vascular invasion could sometimes be observed, there have been no reported cases of local recurrence or distant metastases after resection.3 PAMT is predicted to exhibit benign biological behavior. Therefore, operative resection with a margin of normal tissue is the primary treatment of choice.
References 1. 2. 3.
Takahashi Y, Shimizu S, Ishida T, et al. Plexiform angiomyxoid myofibroblastic tumor of the stomach. Am J Surg Pathol 2007;31:724–728. Duckworth LV, Gonzalez RS, Martelli M, et al. Plexiform fibromyxoma: report of two pediatric cases and review of the literature. Pediatr Dev Pathol 2014;17:21–27. Miettinen M, Makhlouf HR, Sobin LH, et al. Plexiform fibromyxoma: a distinctive benign gastric antral neoplasm not to be confused with a myxoid GIST. Am J Surg Pathol 2009;33:1624–1632.
For submission instructions, please see the Gastroenterology web site (www.gastrojournal.org).
295
