Loss of ARID1A expression in colorectal carcinoma is strongly associated with mismatch repair deficiency.

ARID1A is a tumor suppressor gene involved in chromatin remodelling. ARID1A mutations and loss of protein expression occur commonly in endometrioid and gynecological clear cell carcinoma where they are associated with mismatch repair (MMR) deficiency. We assessed ARID1A expression in a large cohort of colorectal carcinomas (CRCs).

Immunohistochemistry for myc predicts survival in colorectal cancer.

MYC over-expression as determined by molecular means has been reported as a favorable prognostic biomarker in colorectal carcinoma (CRC). However MYC expression analysis is not available in the routine clinical setting. We investigated whether immunohistochemistry (IHC) for the myc protein using a novel commercially available rabbit monoclonal antibody [clone Y69] which is currently in widespread clinical use for lymphoma diagnosis could be used to predict outcome in resected CRC.

BRAFV600E immunohistochemistry in conjunction with mismatch repair status predicts survival in patients with colorectal cancer.

Immunohistochemistry has recently been validated for the detection of the BRAFV600E mutation across a range of tumor types. In colorectal carcinoma, the presence of the BRAFV600E mutation can be used to virtually exclude Lynch syndrome in mismatch repair-deficient tumors. In mismatch repair-proficient tumors, BRAFV600E mutation assessed by molecular methods has been proposed as a poor prognostic factor.

When is a GIST not a GIST? A case report of synchronous metastatic gastrointestinal stromal tumor and fibromatosis.

Background: A number of non-malignant diseases that share similar morphological features as gastrointestinal stromal tumor (GIST) have been reported. Co-existence of GIST with these other diseases is rarely recognized or reported.

Case Presentation: We report a case of a 62 year-old man with long-term stable control of metastatic GIST with systemic therapy, presented with an apparent intra-abdominal progression but not supported by imaging with positron emission tomography.