Digital papillary adenocarcinoma: presentation, natural history and management

Digital papillary adenocarcinoma (DPA) is a rare malignant tumor of the sweat glands that often presents as a solitary painless mass on the digits of the hands or feet. We present a rare case of DPA on the ankle in a 54 year-old African American man. Although the most common location for digital papillary adenocarcinoma is on the hands and feet, it can present in other locations. Treatment modalities and concerns such as the level of margin resection, degree of negative margins, and the need for a sentinel lymph node biopsy might be different if the tumor is encountered in locations other than the digits. In the following manuscript, we discuss the natural history of this rare tumor including a review of the current literature with emphasis on documented treatment strategies as well as the approach in treating patients with a unique presentation

Malignant transformation of non-neoplastic Barrett's epithelial cells through well-defined genetic manipulations.

Human Barrett's cancer cell lines have numerous, poorly-characterized genetic abnormalities and, consequently, those lines have limited utility as models for studying the early molecular events in carcinogenesis. Cell lines with well-defined genetic lesions that recapitulate various stages of neoplastic progression in Barrett's esophagus would be most useful for such studies.To develop such model cell lines, we started with telomerase-immortalized, non-neoplastic Barrett's epithelial (BAR-T) cells, which are spontaneously deficient in p16, and proceeded to knock down p53 using RNAi, to activate Ras by introducing oncogenic H-Ras(G12V), or both. BAR-T cells infected with either p53 RNAi or oncogenic H-Ras(G12V) alone maintained cell-to-cell contact inhibition and did not exhibit anchorage-independent growth in soft agar. In contrast, the combination of p53 RNAi knockdown with expression of oncogenic H-Ras(G12V) transformed the p16-deficient BAR-T cells, as evidenced by their loss of contact inhibition, by their formation of colonies in soft agar, and by their generation of tumors in immunodeficient mice.Through these experiments, we have generated a number of transformed and non-transformed cell lines with well-characterized genetic abnormalities recapitulating various stages of carcinogenesis in Barrett's esophagus. These lines should be useful models for the study of carcinogenesis in Barrett's esophagus, and for testing the efficacy of chemopreventive and chemotherapeutic agents