Mucin immunohistochemistry in the diagnosis and mapping of extramammary Paget's disease.

Extramammary Paget's disease (EMPD) is a rare skin cancer of the genital region in which cancer cells with enlarged nuclei and pale cytoplasm are scattered singly in the affected epidermis. These cancer cells, called Paget cells, contain mucin, which is never found in normal epidermis. The oligosaccharide side chains of Paget cell mucin end with sialic acid. Sialic acid is easily detected by zirconyl haematoxylin or alcian blue. The other sugars in the oligosaccharide chains can be detected by the periodic acid-Shiff reaction. Rarely, the diagnosis of EMPD is complicated by the absence of mucin from the Paget cells. We have examined such an atypical case. The oligosaccharide side chains, including the sialic acids, are absent. In both this case and a typical case, the Paget cells contain epithelial membrane antigen mucin (MUC1) core protein and usually contain gastric surface-type mucin (MUC5AC) core protein, which can be stained by antibodies. Since neither core protein is found in normal epidermis, epithelial membrane antigen core protein may be the most reliable diagnostic marker for extramammary Paget's disease. In both the atypical case and the typical case of Paget's disease, some cells that look like keratinocytes contain mucin core proteins. These may be incipient Paget cells. We suggest that using th epithelial membrane antigen core protein as a marker for the true extent of extramammary Paget's disease could facilitate complete excision and reduce the rate of recurrence.

Admissibility of neuropsychological testimony after Daubert and Kumho.

Neuropsychological testing has been used in court cases all over the United States, as testimony to provide evidence of whether or not a person has a traumatic brain injury. It has, however, been scrutinized for its admissibility in court, but recognized for objectivity in successfully documenting and proving deficits in people with traumatic brain injuries. The trial court is used as a gatekeeper, and may chose to perform assessments of the tests themselves, for validity of sensitivity, specificity, reliability and validity in determining whether a neuropsychological test may be used as testimony in a court case.