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A Bulky Posterior Mediastinal Tumor
ELECTRONIC CLINICAL CHALLENGES AND IMAGES IN GI 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58
A Bulky Posterior Mediastinal Tumor Q2
Kensuke Adachi,1,* Masaru Nemoto,1,* and Kazuaki Enatsu2 1
Department of Surgery, and 2Department of Pathology, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan
Question: A previously healthy 30-year-old man presented at our hospital with a large mass behind the heart, which was incidentally discovered on ultrasonography in the course of his annual medical checkup. He was completely asymptomatic and emphatically denied any weight loss, fever, dysphagia, food impaction, reflux symptoms, or signs of bleeding. The patient’s history and laboratory test results were unremarkable. An axial contrast-enhanced computed tomography (CT) scan showed a well-circumscribed, heterogeneous mass in the left posterolateral mediastinum, measuring 9 7 5 cm (Figure A). The tumor was deemed inseparable from the lower esophageal wall with adjacent mediastinal structures uninvolved. Crescent-shaped gas pockets outlined the compressed esophageal lumen. No regional lymphadenopathy or distant metastatic disease was evident. An esophagogastroduodenoscopy demonstrated a smooth submucosal tumor without mucosal ulceration in the distal esophagus (Figure B). A barium study showed this intramural mass might have caused luminal narrowing without obstruction (Figure C). An endoscopic ultrasonography disclosed a hypoechoic mass containing multiple hyperechoic foci and showing well-defined margins in the muscularis propria (Figure D). A sagittal positron emission tomography (PET) revealed marked 18 F-fluorodeoxyglucose (FDG) uptake in this paraesophageal tumor (Figure E). The patient underwent a distal esophagectomy.
Gastroenterology 2016;-:e1–e3 DIS 5.4.0 DTD YGAST60092 proof 27 February 2016 12:21 pm ce
59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
ELECTRONIC CLINICAL CHALLENGES AND IMAGES IN GI 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174
What is the diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. *Authors share co-first authorship. Q1
Conflicts of interest The authors disclose no conflicts. © 2016 by the AGA Institute 0016-5085/$36.00 http://dx.doi.org/10.1053/j.gastro.2015.10.018
e2 DIS 5.4.0 DTD YGAST60092 proof 27 February 2016 12:21 pm ce
175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232
ELECTRONIC CLINICAL CHALLENGES AND IMAGES IN GI 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
Answer to: Image 4: Esophageal Leiomyoma
The imaging characteristics raised a strong suspicion for a malignant esophageal mesenchymal neoplasm such as a gastrointestinal stromal tumor (GIST) and a Leiomyosarcoma, although both tumors are found rarely in the esophagus. The cut surface of the specimen displayed whitish-gray multiple nodular lesions in the tumor (Figure F). However, postoperative pathology reversed the diagnosis by revealing desmin-positive, intercrossing smooth muscle fibers without nuclear atypia, denying leimyosarcoma (Figure G, stain: hematoxylin & eosin stain; Figure H, stain: antidesmin). Further immunohistochemistry demonstrated negative reactivity for KIT, CD34, and DOG.1. Additionally, the absence of mutation in KIT, or plateletderived growth factor receptor alpha allowed us to rule out GIST. Despite a positive PET result, the Ki-67 index correlating with tumor mitotic activity was <1%. Based on these findings, benign esophageal leiomyoma was diagnosed. Postoperatively, the patient had an uneventful recovery. At postoperative follow-up 2 months later, he was doing well without incident. Although a leiomyoma comprises <1% of all esophageal tumors, it is the most common benign submucosal tumor in the esophagus.1 Its malignant counterpart, a leiomyosarcma has been considered an extremely rare entity in the post-GIST era, whereas a GIST with varying malignancy potential is a common mesenchymal tumor anywhere in the digestive tract.1 Regardless of malignancy potential, these gastrointestinal mesenchymal tumors tend to displace adjacent structures and sometimes grow quite large before they begin producing symptoms while an asymptomatic esophageal leiomyoma can usually be managed nonsurgically.1 When an asymptomatic, esophageal, submucosal tumor has a bulky but noninvasive appearance, establishing the correct diagnosis is sometimes problematic. Although preoperative pathologic diagnosis is essential in general, an endoscopic ultrasound-guided fine-needle aspiration, or thoracoscopic biopsy is controversial because it may precipitate tumor rupture, dissemination, and hemorrhage in large, potentially malignant tumors.2 Further, it often produces inconclusive preoperative and intraoperative findings.2 The present case illustrates the various diagnostic pitfalls one may encounter when presented with a bulky esophageal leiomyoma; however, recourse must be made to various imaging technologies including an upper GI series, endoscopy, endoscopic ultrasonography, CT, and PET/CT1, as in the case reported herein. Because of the unlikelihood of malignant degeneration, it is of paramount importance to differentiate a benign esophageal leiomyoma from a malignant mesenchymal neoplasm, especially an esophageal GIST. The latter is likely to display a larger size, occasional mucosal ulceration on endoscopy, greater heterogeneity with contrast enhancement on CT, greater heterogeneous echogenicity on endoscopic ultrasonography, and hypermetabolic avidity on PET/CT.1 PET/CT is a valuable diagnostic tool widely used to visualize malignant and inflammatory conditions. In malignant neoplasms, FDG uptake as visualized by PET/CT actually correlates with the aggressiveness of the tumor. Abnormal FDG accumulation in esophageal diseases is also observed in various nononcologic, inflammatory conditions including infection, gastroesophageal reflux, acanthosis, and Barret’s esophagus.3 Such conditions may go unidentified, and explaining the pathology that gave rise to the false-positive PET result may be difficult despite low Ki-67 scores. A strong clinical suspicion is a good point of departure, and familiarity with the imaging characteristics of the disease is crucial to render an accurate diagnosis. Although imaging features may facilitate differentiation of a benign esophageal leiomyoma and a malignant esophageal mesenchymal tumor, our case illustrated how a misdiagnosis can result even after integrating all of the findings from the different imaging modalities.
References 1. 2. 3.
Winant AJ, Gollub MJ, Shia J, et al. Imaging and clinicopathologic features of esophageal gastrointestinal stromal tumors. Am J Roentgenol 2014;203:306–314. Stelow EB, Stanley MW, Mallery S, et al. Endoscopic ultrasound-guided fine-needle aspiration findings of gastrointestinal leiomyomas and gastrointestinal stromal tumors. Am J Clin Pathol 2003;119:703–708. Depypere L, Coosemans W, Nafteux P. Fluorine-18-fluorodeoxyglucose uptake in a benign oesophageal leiomyoma: a potential pitfall in diagnosis. Interac Cardiovasc Thorac Surg 2012;14:234–236. e3 DIS 5.4.0 DTD YGAST60092 proof 27 February 2016 12:21 pm ce
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A Bulky Posterior Mediastinal Tumor Q2
Kensuke Adachi,1,* Masaru Nemoto,1,* and Kazuaki Enatsu2 1
Department of Surgery, and 2Department of Pathology, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan
Question: A previously healthy 30-year-old man presented at our hospital with a large mass behind the heart, which was incidentally discovered on ultrasonography in the course of his annual medical checkup. He was completely asymptomatic and emphatically denied any weight loss, fever, dysphagia, food impaction, reflux symptoms, or signs of bleeding. The patient’s history and laboratory test results were unremarkable. An axial contrast-enhanced computed tomography (CT) scan showed a well-circumscribed, heterogeneous mass in the left posterolateral mediastinum, measuring 9 7 5 cm (Figure A). The tumor was deemed inseparable from the lower esophageal wall with adjacent mediastinal structures uninvolved. Crescent-shaped gas pockets outlined the compressed esophageal lumen. No regional lymphadenopathy or distant metastatic disease was evident. An esophagogastroduodenoscopy demonstrated a smooth submucosal tumor without mucosal ulceration in the distal esophagus (Figure B). A barium study showed this intramural mass might have caused luminal narrowing without obstruction (Figure C). An endoscopic ultrasonography disclosed a hypoechoic mass containing multiple hyperechoic foci and showing well-defined margins in the muscularis propria (Figure D). A sagittal positron emission tomography (PET) revealed marked 18 F-fluorodeoxyglucose (FDG) uptake in this paraesophageal tumor (Figure E). The patient underwent a distal esophagectomy.
Gastroenterology 2016;-:e1–e3 DIS 5.4.0 DTD YGAST60092 proof 27 February 2016 12:21 pm ce
59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
ELECTRONIC CLINICAL CHALLENGES AND IMAGES IN GI 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174
What is the diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. *Authors share co-first authorship. Q1
Conflicts of interest The authors disclose no conflicts. © 2016 by the AGA Institute 0016-5085/$36.00 http://dx.doi.org/10.1053/j.gastro.2015.10.018
e2 DIS 5.4.0 DTD YGAST60092 proof 27 February 2016 12:21 pm ce
175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232
ELECTRONIC CLINICAL CHALLENGES AND IMAGES IN GI 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
Answer to: Image 4: Esophageal Leiomyoma
The imaging characteristics raised a strong suspicion for a malignant esophageal mesenchymal neoplasm such as a gastrointestinal stromal tumor (GIST) and a Leiomyosarcoma, although both tumors are found rarely in the esophagus. The cut surface of the specimen displayed whitish-gray multiple nodular lesions in the tumor (Figure F). However, postoperative pathology reversed the diagnosis by revealing desmin-positive, intercrossing smooth muscle fibers without nuclear atypia, denying leimyosarcoma (Figure G, stain: hematoxylin & eosin stain; Figure H, stain: antidesmin). Further immunohistochemistry demonstrated negative reactivity for KIT, CD34, and DOG.1. Additionally, the absence of mutation in KIT, or plateletderived growth factor receptor alpha allowed us to rule out GIST. Despite a positive PET result, the Ki-67 index correlating with tumor mitotic activity was <1%. Based on these findings, benign esophageal leiomyoma was diagnosed. Postoperatively, the patient had an uneventful recovery. At postoperative follow-up 2 months later, he was doing well without incident. Although a leiomyoma comprises <1% of all esophageal tumors, it is the most common benign submucosal tumor in the esophagus.1 Its malignant counterpart, a leiomyosarcma has been considered an extremely rare entity in the post-GIST era, whereas a GIST with varying malignancy potential is a common mesenchymal tumor anywhere in the digestive tract.1 Regardless of malignancy potential, these gastrointestinal mesenchymal tumors tend to displace adjacent structures and sometimes grow quite large before they begin producing symptoms while an asymptomatic esophageal leiomyoma can usually be managed nonsurgically.1 When an asymptomatic, esophageal, submucosal tumor has a bulky but noninvasive appearance, establishing the correct diagnosis is sometimes problematic. Although preoperative pathologic diagnosis is essential in general, an endoscopic ultrasound-guided fine-needle aspiration, or thoracoscopic biopsy is controversial because it may precipitate tumor rupture, dissemination, and hemorrhage in large, potentially malignant tumors.2 Further, it often produces inconclusive preoperative and intraoperative findings.2 The present case illustrates the various diagnostic pitfalls one may encounter when presented with a bulky esophageal leiomyoma; however, recourse must be made to various imaging technologies including an upper GI series, endoscopy, endoscopic ultrasonography, CT, and PET/CT1, as in the case reported herein. Because of the unlikelihood of malignant degeneration, it is of paramount importance to differentiate a benign esophageal leiomyoma from a malignant mesenchymal neoplasm, especially an esophageal GIST. The latter is likely to display a larger size, occasional mucosal ulceration on endoscopy, greater heterogeneity with contrast enhancement on CT, greater heterogeneous echogenicity on endoscopic ultrasonography, and hypermetabolic avidity on PET/CT.1 PET/CT is a valuable diagnostic tool widely used to visualize malignant and inflammatory conditions. In malignant neoplasms, FDG uptake as visualized by PET/CT actually correlates with the aggressiveness of the tumor. Abnormal FDG accumulation in esophageal diseases is also observed in various nononcologic, inflammatory conditions including infection, gastroesophageal reflux, acanthosis, and Barret’s esophagus.3 Such conditions may go unidentified, and explaining the pathology that gave rise to the false-positive PET result may be difficult despite low Ki-67 scores. A strong clinical suspicion is a good point of departure, and familiarity with the imaging characteristics of the disease is crucial to render an accurate diagnosis. Although imaging features may facilitate differentiation of a benign esophageal leiomyoma and a malignant esophageal mesenchymal tumor, our case illustrated how a misdiagnosis can result even after integrating all of the findings from the different imaging modalities.
References 1. 2. 3.
Winant AJ, Gollub MJ, Shia J, et al. Imaging and clinicopathologic features of esophageal gastrointestinal stromal tumors. Am J Roentgenol 2014;203:306–314. Stelow EB, Stanley MW, Mallery S, et al. Endoscopic ultrasound-guided fine-needle aspiration findings of gastrointestinal leiomyomas and gastrointestinal stromal tumors. Am J Clin Pathol 2003;119:703–708. Depypere L, Coosemans W, Nafteux P. Fluorine-18-fluorodeoxyglucose uptake in a benign oesophageal leiomyoma: a potential pitfall in diagnosis. Interac Cardiovasc Thorac Surg 2012;14:234–236. e3 DIS 5.4.0 DTD YGAST60092 proof 27 February 2016 12:21 pm ce
291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348