Myeloid sarcoma of the small bowel associated with a CBFbeta/MYH11 fusion and inv(16)(p13q22): a case report

This report describes a case of aleukaemic myeloid sarcoma of the small intestine in a 50-year-old woman presenting with small bowel obstruction. Fluorescence in situ hybridisation analysis of interphase nuclei revealed a split CBFbeta signal, consistent with an underlying inversion of chromosome 16, inv(16)(p13q22). The resultant type A CBFbeta/MYH11 transcript was detected by reverse transcriptase PCR. Immunohistochemistry with the AH107 antibody to the CBFbeta-SMMHC chimeric protein showed strong nuclear staining of the tumour cell nuclei. This represents the first use of this antibody in the diagnosis of this subtype of myeloid sarcoma in the small intestine.