TY - JOUR
T1 - Gastric schwannoma
T2 - A clinicopathologic study of 51 cases and critical review of the literature
AU - Voltaggio, Lysandra
AU - Murray, Rebecca
AU - Lasota, Jerzy
AU - Miettinen, Markku
N1 - Funding Information:
This research was supported in part by the intramural research program of the National Institutes of Health and the National Cancer Institute .
PY - 2012/5
Y1 - 2012/5
N2 - Schwannoma is a rare gastrointestinal mesenchymal tumor, as the vast majority of gastric mesenchymal tumors are gastrointestinal stromal tumors. In this study, we analyzed clinicopathologically 51 gastric schwannomas. These tumors predominantly occurred in older adults with a marked female predominance (40 women and 11 men; median and mean ages, 60 and 58 years). They variably presented with gastric discomfort, bleeding, or rarely gastric outlet obstruction; and many were incidental findings during other medical procedures. The tumors ranged from 1 to 10.5 cm (median, 4.5 cm). The typical histologic features included spindle cells usually with microtrabecular architecture and focal nuclear atypia, and peritumoral lymphoid cuff, whereas features of soft tissue schwannomas, such as encapsulation, nuclear palisading, vascular hyalinization, and dilatation, were absent or infrequent. Median mitotic count was 2/50 high-power fields, with the highest count being 13/50 high-power fields. No malignant variants were recognized, and long-term follow-up did not reveal recurrences or metastases. Immunohistochemically, all examined tumors were S100 protein positive and most were also GFAP positive, whereas CD34 and NF68 were encountered rarely and all tumors were negative for HMB45, KIT, DOG1/Ano 1, smooth muscle actin, desmin, and synaptophysin. None of the 9 tumors studied contained gastrointestinal stromal tumor-specific KIT or PDGFRA mutations. Fluorescence in situ hybridization studies revealed multiple signals with BCR probe (chromosome 22) and centromeric probes for chromosomes 2 and 18 suggesting polyploidy. These findings indicate that gastric schwannoma is a distinctive form of peripheral nerve sheath tumor that in many ways differs from soft tissue schwannoma. It should be distinguished from gastrointestinal stromal tumor and other mesenchymal tumors of the gastrointestinal tract, such as the S100 protein-positive gastrointestinal clear cell sarcoma and metastatic melanoma.
AB - Schwannoma is a rare gastrointestinal mesenchymal tumor, as the vast majority of gastric mesenchymal tumors are gastrointestinal stromal tumors. In this study, we analyzed clinicopathologically 51 gastric schwannomas. These tumors predominantly occurred in older adults with a marked female predominance (40 women and 11 men; median and mean ages, 60 and 58 years). They variably presented with gastric discomfort, bleeding, or rarely gastric outlet obstruction; and many were incidental findings during other medical procedures. The tumors ranged from 1 to 10.5 cm (median, 4.5 cm). The typical histologic features included spindle cells usually with microtrabecular architecture and focal nuclear atypia, and peritumoral lymphoid cuff, whereas features of soft tissue schwannomas, such as encapsulation, nuclear palisading, vascular hyalinization, and dilatation, were absent or infrequent. Median mitotic count was 2/50 high-power fields, with the highest count being 13/50 high-power fields. No malignant variants were recognized, and long-term follow-up did not reveal recurrences or metastases. Immunohistochemically, all examined tumors were S100 protein positive and most were also GFAP positive, whereas CD34 and NF68 were encountered rarely and all tumors were negative for HMB45, KIT, DOG1/Ano 1, smooth muscle actin, desmin, and synaptophysin. None of the 9 tumors studied contained gastrointestinal stromal tumor-specific KIT or PDGFRA mutations. Fluorescence in situ hybridization studies revealed multiple signals with BCR probe (chromosome 22) and centromeric probes for chromosomes 2 and 18 suggesting polyploidy. These findings indicate that gastric schwannoma is a distinctive form of peripheral nerve sheath tumor that in many ways differs from soft tissue schwannoma. It should be distinguished from gastrointestinal stromal tumor and other mesenchymal tumors of the gastrointestinal tract, such as the S100 protein-positive gastrointestinal clear cell sarcoma and metastatic melanoma.
KW - Chromosome 22
KW - GFAP
KW - Nerve sheath tumor
KW - Polyploidy
KW - Prognosis
KW - S100 protein
KW - Schwannoma
KW - Stomach
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U2 - 10.1016/j.humpath.2011.07.006
DO - 10.1016/j.humpath.2011.07.006
M3 - Article
C2 - 22137423
AN - SCOPUS:84859882767
SN - 0046-8177
VL - 43
SP - 650
EP - 659
JO - Human pathology
JF - Human pathology
IS - 5
ER -