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Pancreatic Schwannoma in a 32-Year-Old Woman Mimicking a Solid-Pseudopapillary Neoplasm
Image of the Month Pancreatic Schwannoma in a 32-Year-Old Woman Mimicking a Solid-Pseudopapillary Neoplasm MINORU OSHIMA, SHINICHI YACHIDA, and YASUYUKI SUZUKI Department of Gastroenterological Surgery, Faculty of Medicine, Kagawa University, Ikenobe, Miki-cho, Kita-gun, Kagawa, Japan
A
32-year-old Japanese woman presented with a chief complaint of back pain. On admission, her past medical history, physical examination, and laboratory values, including tumor markers, were unremarkable. Ultrasonography showed a hypoechoic tumor, measuring 4.0 cm in diameter, within the head of the pancreas. Precontrast computed tomography showed this tumor to be a well-demarcated, low-density lesion with a highdensity component (Figure A). After contrast administration, the lesion showed heterogeneous low density with a highdensity component in the center (Figure B). Magnetic resonance imaging revealed the tumor to be homogenously hypointense on T1-weighted sequences (Figure C) and heterogeneously hyperintense with hypointense areas on T2-weighted sequences (Figure D). These radiographic findings were suggestive of the presence of hemorrhage in various phases and degenerative changes, including cyst formation. This tumor, based on clinical manifestations and radiologic features, was suspected to be a solid-pseudopapillary neoplasm (SPN). Pancreaticoduodenectomy was performed. Examination of the cut surface of the resected specimen showed a firm, whitish, 3.5-cm, well-circumscribed, encapsulated solid tumor with focal areas of degenerative changes: cyst formation, necrosis, and
hemorrhage (Figure E). Microscopically, the lesion was surrounded by a thick fibrocollagenous capsule and normal pancreatic parenchyma. The lesion showed varying degrees of cellularity. The cellular areas were composed of spindle cells with elongated nuclei, which were arranged in fascicles (Figure F). The hypocellular area showed cyst formation, hemorrhage, hemosiderin-laden macrophages, and an edematous stroma. The spindle cell population in the cellular component strongly stained positive for S100 protein and negative for cytokeratins, epithelial membrane antigen, smooth muscle actin, desmin, neurofilament, CD34, and CD117 (c-kit). The tumor was diagnosed as a pancreatic schwannoma from these findings. The Acknowledgments The authors thank Dr Christine A. Iacobuzio-Donahue (Johns Hopkins Medical Institutions) for the critical reading of the manuscript. Conflicts of interest The authors disclose no conflicts. © 2010 by the AGA Institute 1542-3565/10/$36.00 doi:10.1016/j.cgh.2009.05.030 CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2010;8:e1– e2
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IMAGE OF THE MONTH
postoperative course was good, and as of this writing she has survived for more than 3 years without any further treatment, without any evidence of recurrence or metastasis. The pancreatic schwannoma is an extremely rare benign mesenchymal neoplasm of the pancreas. A Medline search of the literature indicated only 46 cases were reported from 1948 through 2008.1,2 The mean patient age at the time of diagnosis was 58.2 years (range, 32– 89 y) and the male-tofemale ratio was 20:26. The mean reported size was 7.86 cm (range, 2–26 cm). The lesion was distributed relatively evenly throughout the pancreas. The majority of schwannomas featured pronounced degenerative changes, including cyst formation, calcification, hemorrhage, hyalinization, and xanthomatous infiltration. Therefore, pancreatic schwannomas often present as cystic, necrotic, and hemorrhage masses on radiographic examination. The most important issue is the difficulty in making the correct preoperative diagnosis. The clinicoradiologic findings for pancreatic schwannomas are similar to those of cystic tumors
CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 8, No. 1
of the pancreas. Pancreatic schwannomas in young women can be especially difficult to diagnose preoperatively because the radiographic findings are very similar to those of pancreatic SPNs. SPNs with a median tumor size of 7 cm (range, 4 –16 cm) typically have been described in young women.3 They usually are well circumscribed, surrounded by a fibrous pseudocapsule, and may be almost entirely solid, varying to cystic with evidence of hemorrhagic degeneration. The present case of a pancreatic schwannoma mimicking SPN highlights the importance of considering this entity in the differential diagnosis of SPN. References 1. Paranjape C, Johnson SR, Khwaja K, et al. Clinical characteristics, treatment, and outcome of pancreatic schwannomas. J Gastrointest Surg 2004;8:706 –712. 2. Tafe LJ, Suriawinata AA. Cystic pancreatic schwannoma in a 46year-old man. Ann Diagn Pathol 2008;12:296 –300. 3. Gleeson FC, Smyrk TC, Chari ST. Asymptomatic solid pseudopapillary neoplasm of the pancreas. Clin Gastroenterol Hepatol 2008;6:A22.
A
32-year-old Japanese woman presented with a chief complaint of back pain. On admission, her past medical history, physical examination, and laboratory values, including tumor markers, were unremarkable. Ultrasonography showed a hypoechoic tumor, measuring 4.0 cm in diameter, within the head of the pancreas. Precontrast computed tomography showed this tumor to be a well-demarcated, low-density lesion with a highdensity component (Figure A). After contrast administration, the lesion showed heterogeneous low density with a highdensity component in the center (Figure B). Magnetic resonance imaging revealed the tumor to be homogenously hypointense on T1-weighted sequences (Figure C) and heterogeneously hyperintense with hypointense areas on T2-weighted sequences (Figure D). These radiographic findings were suggestive of the presence of hemorrhage in various phases and degenerative changes, including cyst formation. This tumor, based on clinical manifestations and radiologic features, was suspected to be a solid-pseudopapillary neoplasm (SPN). Pancreaticoduodenectomy was performed. Examination of the cut surface of the resected specimen showed a firm, whitish, 3.5-cm, well-circumscribed, encapsulated solid tumor with focal areas of degenerative changes: cyst formation, necrosis, and
hemorrhage (Figure E). Microscopically, the lesion was surrounded by a thick fibrocollagenous capsule and normal pancreatic parenchyma. The lesion showed varying degrees of cellularity. The cellular areas were composed of spindle cells with elongated nuclei, which were arranged in fascicles (Figure F). The hypocellular area showed cyst formation, hemorrhage, hemosiderin-laden macrophages, and an edematous stroma. The spindle cell population in the cellular component strongly stained positive for S100 protein and negative for cytokeratins, epithelial membrane antigen, smooth muscle actin, desmin, neurofilament, CD34, and CD117 (c-kit). The tumor was diagnosed as a pancreatic schwannoma from these findings. The Acknowledgments The authors thank Dr Christine A. Iacobuzio-Donahue (Johns Hopkins Medical Institutions) for the critical reading of the manuscript. Conflicts of interest The authors disclose no conflicts. © 2010 by the AGA Institute 1542-3565/10/$36.00 doi:10.1016/j.cgh.2009.05.030 CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2010;8:e1– e2
e2
IMAGE OF THE MONTH
postoperative course was good, and as of this writing she has survived for more than 3 years without any further treatment, without any evidence of recurrence or metastasis. The pancreatic schwannoma is an extremely rare benign mesenchymal neoplasm of the pancreas. A Medline search of the literature indicated only 46 cases were reported from 1948 through 2008.1,2 The mean patient age at the time of diagnosis was 58.2 years (range, 32– 89 y) and the male-tofemale ratio was 20:26. The mean reported size was 7.86 cm (range, 2–26 cm). The lesion was distributed relatively evenly throughout the pancreas. The majority of schwannomas featured pronounced degenerative changes, including cyst formation, calcification, hemorrhage, hyalinization, and xanthomatous infiltration. Therefore, pancreatic schwannomas often present as cystic, necrotic, and hemorrhage masses on radiographic examination. The most important issue is the difficulty in making the correct preoperative diagnosis. The clinicoradiologic findings for pancreatic schwannomas are similar to those of cystic tumors
CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 8, No. 1
of the pancreas. Pancreatic schwannomas in young women can be especially difficult to diagnose preoperatively because the radiographic findings are very similar to those of pancreatic SPNs. SPNs with a median tumor size of 7 cm (range, 4 –16 cm) typically have been described in young women.3 They usually are well circumscribed, surrounded by a fibrous pseudocapsule, and may be almost entirely solid, varying to cystic with evidence of hemorrhagic degeneration. The present case of a pancreatic schwannoma mimicking SPN highlights the importance of considering this entity in the differential diagnosis of SPN. References 1. Paranjape C, Johnson SR, Khwaja K, et al. Clinical characteristics, treatment, and outcome of pancreatic schwannomas. J Gastrointest Surg 2004;8:706 –712. 2. Tafe LJ, Suriawinata AA. Cystic pancreatic schwannoma in a 46year-old man. Ann Diagn Pathol 2008;12:296 –300. 3. Gleeson FC, Smyrk TC, Chari ST. Asymptomatic solid pseudopapillary neoplasm of the pancreas. Clin Gastroenterol Hepatol 2008;6:A22.