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Retroperitoneal Benign Schwannoma in the Suprapancreatic Area
Image of the Month Retroperitoneal Benign Schwannoma in the Suprapancreatic Area MASAO HASHIMOTO, YOSHIFUMI BECK, and MASATOSHI MAKUUCHI Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
enucleation was performed. Histologic examination showed the mass consisting of bundles of spindle cells with hypercellular and hypocellular areas and prominent cystic degeneration (Figure C). Immunohistochemical studies revealed that the tumor was positive for S-100 protein (Figure D), negative for c-Kit antigen (Figure E), and negative for CD34 (Figure F). The final pathologic diagnosis was a benign schwannoma. Preoperative diagnosis of schwannoma is difficult because it does not have any specific ultrasonography, computerized tomography, or magnetic resonance imaging features. Cystic lesions with sporadic internal echoes are common features in larger schwannomas, in which cystic degeneration and hemorrhage has occurred.1 When the mass is small, however, it usually is solid,2 and presents with a hypoechoic pattern.1 On the other hand, the possibility of variable cystic degeneration in schwannomas can lead to unique imaging features, such as the Swiss cheese–like appearance observed in the present case, even when the mass is smaller than 5 cm in diameter.
References 1. Kuo CH, Changchien CS. Sonographic features of retroperitoneal neurilemoma. J Clin Ultrasound 1993;21:309 –312. 2. Regan JF, Juler GL, Schmutzer KJ. Retroperitoneal neurilemoma. Am J Surg 1977;134:140 –145.
A
round mass with a diameter of 4.5 cm was found in the suprapancreatic area of a 43-year-old woman by ultrasonography. Multiple cystic components within the solid mass contributed to a Swiss cheese–like appearance (Figure A). Computed tomography showed a heterogeneous mass consisting of a low and gradually enhanced solid mass (Figure B). Differential diagnosis included schwannoma, gastrointestinal stromal tumor, solitary fibrous tumor, malignant histiocytoma, and cystic neoplasms of the pancreas. Tumor
© 2008 by the AGA Institute
1542-3565/08/$34.00 doi:10.1016/j.cgh.2007.10.023 CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2008;6:e3– e4
e4
HASHIMOTO ET AL
CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 6, No. 1
enucleation was performed. Histologic examination showed the mass consisting of bundles of spindle cells with hypercellular and hypocellular areas and prominent cystic degeneration (Figure C). Immunohistochemical studies revealed that the tumor was positive for S-100 protein (Figure D), negative for c-Kit antigen (Figure E), and negative for CD34 (Figure F). The final pathologic diagnosis was a benign schwannoma. Preoperative diagnosis of schwannoma is difficult because it does not have any specific ultrasonography, computerized tomography, or magnetic resonance imaging features. Cystic lesions with sporadic internal echoes are common features in larger schwannomas, in which cystic degeneration and hemorrhage has occurred.1 When the mass is small, however, it usually is solid,2 and presents with a hypoechoic pattern.1 On the other hand, the possibility of variable cystic degeneration in schwannomas can lead to unique imaging features, such as the Swiss cheese–like appearance observed in the present case, even when the mass is smaller than 5 cm in diameter.
References 1. Kuo CH, Changchien CS. Sonographic features of retroperitoneal neurilemoma. J Clin Ultrasound 1993;21:309 –312. 2. Regan JF, Juler GL, Schmutzer KJ. Retroperitoneal neurilemoma. Am J Surg 1977;134:140 –145.
A
round mass with a diameter of 4.5 cm was found in the suprapancreatic area of a 43-year-old woman by ultrasonography. Multiple cystic components within the solid mass contributed to a Swiss cheese–like appearance (Figure A). Computed tomography showed a heterogeneous mass consisting of a low and gradually enhanced solid mass (Figure B). Differential diagnosis included schwannoma, gastrointestinal stromal tumor, solitary fibrous tumor, malignant histiocytoma, and cystic neoplasms of the pancreas. Tumor
© 2008 by the AGA Institute
1542-3565/08/$34.00 doi:10.1016/j.cgh.2007.10.023 CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2008;6:e3– e4
e4
HASHIMOTO ET AL
CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 6, No. 1