Gastrointestinal stromal tumor of small intestine associated with lymph node metastasis: a report of 2 cases with review of literatures / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of gastrointestinal stromal tumor (GIST) of small intestine with lymph node metastasis and evaluate the respond to imatinib mesylate (Glivec) therapy.</p><p><b>METHODS</b>Two cases of GIST of small intestine associated with lymph node metastasis were collected and investigated by light microscopy and immunohistochemistry. Mutation in exon 9, 11 and of c-kit gene were analyzed by polymerase chain reaction and DNA sequencing.</p><p><b>RESULTS</b>The cases presented as small intestinal mass of irregular shape. Histologically, the tumors consisted of epithelioid and spindled cells, with areas of coagulative necrosis and hemorrhage. The mitotic count measured about 2 per 50 high-power fields. Immunohistochemical study showed that the tumor cells were diffusely distributed and strongly positive for CD117. Mutation analysis revealed that case 1 had an in-frame deletion of 11 amino-acid residues corresponding to 559-569 and carried two missense mutations involving codons 570, 571 in exon 11 of c-kit gene. Case 2 revealed an in-frame deletion involved condons 559-565 in exon 11 of c-kit gene. These two cases were all underwent primary chemotherapy with imatinib mesylate and without new tumor was found during follow-up periods (18, 26 months) after operation.</p><p><b>CONCLUSIONS</b>GIST with nodal metastasis is very rare and needs to be distinguished from other soft tissue sarcomas occurring in this site. The responsiveness to imatinib mesylate therapy correlates with the mutation status of c-kit gene.</p>

Sclerosing angiomatoid nodular transformation of spleen / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of sclerosing angiomatoid nodular transformation of spleen and its differential diagnosis.</p><p><b>METHODS</b>The clinicopathologic characteristics and immunophenotype of 4 cases of sclerosing angiomatoid nodular transformation of spleen were studied.</p><p><b>RESULTS</b>Histologically, all cases were characterized by multiple angiomatoid nodules of various sizes in a fibrosclerotic stroma. The nodules were round and sometimes convoluted. They were composed of slit-like, irregular-shaped or slightly dilated vascular spaces lined by plump endothelial cells and interspersed with a population of spindly or ovoid cells. Immunohistochemical study showed a heterogeneous staining pattern, with the lining cells of the small capillaries expressing CD34 and those of the sinusoid-like structures expressing CD8. CD31 highlighted both the lining cells and interspersed cells, resulting in a complex meshwork. The lining cells were also focally positive for CD68. Smooth muscle actin revealed conglomerates of spindly shaped cells around and between the vascular channels. These spindly shaped cells in the intervening stroma were focally positive for actin, but negative for desmin, CD21 and CD35.</p><p><b>CONCLUSIONS</b>Sclerosing angiomatoid nodular transformation is a rarely encountered benign lesion of the spleen, which should be distinguished from other angiomatoid tumors and tumor-like lesions.</p>

Inflammatory myofibroblastic tumor of bladder: a clinicopathologic study of five cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features, diagnosis and differential diagnosis of inflammatory myofibroblastic tumor of the urinary bladder.</p><p><b>METHODS</b>Excisional specimens from 5 cases of vesical inflammatory myofibroblastic tumor were studied by light microscopy and immunohistochemistry (EnVision). The clinical data were also analyzed.</p><p><b>RESULTS</b>Among the 5 patients studied, 3 were males and 2 were females. The age of the patients ranged from 10 to 53 years (mean age = 35 years). The most common clinical presentation was micturition pain and hematuria. Three cases were located at the dome of the urinary bladder and the remaining 2 cases were found in the left lateral wall. Histologically, the tumor varied from myxoid to highly cellular. The tumor cells were spindle to stellate in shape, widely separated or showed a compact fascicular pattern. There were often associated with mixed inflammatory infiltrates and an irregular meshwork of small dilated vessels. Immunohistochemical study showed that the tumor cells expressed AE1/AE3 (5/5), vimentin (5/5), smooth muscle actin (5/5), calponin (5/5), caldesmon (3/5), desmin (4/5) and anaplastic lymphoma kinase protein (4/5). Follow-up data were available in 4 patients and none had local recurrence or died of this disease.</p><p><b>CONCLUSION</b>Inflammatory myofibroblastic tumour of urinary bladder is a rarely encountered but distinctive neoplasm with intermediate malignant potential.</p>