Granular cell tumor of cecum.

Granular cell tumors are uncommon in the gastrointestinal tract. They are often found incidentally during colonoscopic examination performed for other reasons as they are frequently asymptomatic and benign. They usually present as submucosal lesions that can be endoscopically resected. The final diagnosis depends on histopathological findings. We present the case of a 47-year-old man that underwent an endoscopic resection of several polyps at the time of colonoscopy with nonspecific complaints and family history of colorectal carcinoma.

Aggressive large B-cell lymphoma with plasma cell differentiation: immunohistochemical characterization of plasmablastic lymphoma and diffuse large B-cell lymphoma with partial plasmablastic phenotype.

BACKGROUND: Plasmablastic lymphoma has recently come to be considered a distinct entity among mature B cell neoplasms, although the limits with diffuse large B-cell lymphoma (DLBCL) need to be more accurately defined. DESIGN AND METHODS: Here we show the results of an immunohistochemical study of 35 cases of plasmablastic lymphoma compared with a set of 111 conventional DLBCLs. RESULTS: Our results demonstrate that the use of a limited combination of immunohistochemical markers (PAX5&CD20, PRDM1/BLIMP1 and XBP1s) enables the identification of a plasmablastic immunophenotype highly characteristic of plasmablastic lymphoma cases and associated with an aggressive clinical behavior. Additionally, the study shows that the acquisition of a partial plasmablastic phenotype (PRDM1/BLIMP1 expression) in DLBCL is associated with shorter survival in R-CHOP-treated patients. CONCLUSIONS: The use of a restricted combination of immunohistochemical markers (PAX5&CD20, PRDM1/BLIMP1 and XBP1s) enables a more accurate definition of terminal differentiation for large B-cell lymphoma.