Gastrointestinal Stromal Tumor Accompanied with von Recklinghausen's Disease: Positive for CD117, CD34, SMA and S-100 Protein

Gastrointestinal stromal tumors (GISTs) are CD117-positive primary mesenchymal tumors of the gastrointestinal tract and they have a characteristic set of morphologic features. GISTs have been noted to have a possible non-random association with neurofibromatosis-1 (NF-1, von Recklinghausen disease). We report here on a case of multiple GISTs with abundant skenoid fiber in the jejunum of a 47-year-old woman, and this condition was accompanied with NF-1. The tumor cells coexpressed smooth muscle actin, S-100 protein, CD117 and CD34. These immunohistochemical results are extremely rare findings for GISTs accompanying with NF-1. We think this is the first report of GISTs arising within NF-1 with the dual immunohistochemical differentiation of neuronal and muscular markers.

Preferential Expression of CD44 in Thyroid Papillary Carcinoma

BACKGROUND: Papillary carcinoma is one of the most common malignant thyroid tumors and an important prognostic factor is the lymph node status. CD44 is a cell adhesion molecule and is associated with metastasis. The purpose of this study was to discover whether CD44 is valuable in the diagnosis of the papillary carcinoma, and whether Ki-67 and p53 are correlated with CD44 in the papillary carcinoma. METHODS: We studied CD44, Ki-67 and p53 expressions in 34 cases of formalin-fixed paraffin embedded papillary thyroid carcinomas, and 20 cases of the follicular neoplasm using mouse anti-CD44 (H-CAM), Ki-67 and p53 monoclonal antibodies. RESULTS: Most of the papillary carcinomas expressed diffuse and intense membrane staining of CD44 (32/34 cases, 94.1%). Focal scattered immunoreactivity was observed in the follicular neoplasm (8/20 cases, 40.0%). The staining patterns of CD44 were similar in both follicular adenoma and carcinoma. Both groups with or without lymph node metastasis showed similar expression patterns for CD44. There were no differences in Ki-67 and p53 staining between papillary carcinomas and follicular neoplasms. CONCLUSIONS: The result shows that papillary carcinomas preferentially display the CD44 antigen, and it is a useful diagnostic tool in the equivocal cases. There is no correlation among CD44, Ki-67 and p53 expressions in the papillary carcinoma.