Examination of mutations in BRAF, NRAS, and PTEN in primary cutaneous melanoma.

Frequent somatic mutation of v-raf murine sarcoma viral oncogene homolog B (BRAF), a downstream effector of the rat sarcoma oncogene (RAS) signaling pathway, is described in melanoma and other tumors. Our analysis of melanoma cell lines suggests that activating mutations in BRAF can occur simultaneously with inactivation of phosphatase and tensin homolog (PTEN), but neuroblastoma RAS (NRAS) mutations are not coincident. We determined the concurrent prevalence of mutations in BRAF and NRAS, and alteration of PTEN expression in 69 primary cutaneous melanomas.

Primitive nonneural granular cell tumors of skin: clinicopathologic analysis of 13 cases.

A rare subset of distinctive cutaneous nonneural granular cell tumors was described by LeBoit et al in 1991 and termed "primitive polypoid granular-cell tumor." Herein, we report our experience with 13 similar, distinctive nonneural granular cell tumors. Affected patients included 7 males and 6 females ranging in age from 5 to 83 years (mean, 25 years; median, 16 years).

Basal cell carcinoma with matrical differentiation: a case study with analysis of beta-catenin.

Matrical differentiation in basal cell carcinoma (BCC) is rare. Only nine cases have been described that showed typical diagnostic features of BCC, in addition to shadow cells indicating hair-matrix differentiation. These cases often present a diagnostic challenge due to confusion with pilomatrixoma or pilomatrix carcinoma.

Pilomatrix carcinomas contain mutations in CTNNB1, the gene encoding beta-catenin.

Mutations in beta-catenin are present in benign pilomatrixomas. beta-catenin is a downstream effector in the WNT-signalling pathway, acting as a signal for differentiation and proliferation. Mutations in CTNNB1, the gene encoding beta-catenin, are present in a wide variety of benign and malignant neoplasms.

Insights into developmental mechanisms and cancers in the mammalian intestine derived from serial analysis of gene expression and study of the hepatoma-derived growth factor (HDGF).

The vertebrate intestine is a model for investigating inductive cellular interactions and the roles of epithelial stem cells in tissue regeneration, and for understanding parallels between development and cancer. We have used serial analysis of gene expression to measure transcript levels across stages in mouse intestine development. The data (http://genome.

Distinctive dermal clear cell mesenchymal neoplasm: clinicopathologic analysis of five cases.

Dermal clear cell tumors are not common. This group of lesions is comprised primarily of clear cell adnexal lesions, balloon cell melanocytic lesions, and metastatic clear cell carcinomas. We report the clinicopathologic features of five cases of a novel dermal clear cell neoplasm that appears mesenchymal in nature.