Vitamin A depletion induced by cigarette smoke is associated with the development of emphysema in rats.

We showed previously that vitamin A deficiency per se causes emphysema. Benzo(a)pyrene, a constituent in cigarette smoke, induces vitamin A depletion when administered to rats; therefore, we tested the hypothesis that cigarette smoke induces vitamin A depletion, which is associated with the development of emphysema. Male weanling rats were fed a purified AIN-93G diet and divided into two groups.

Expression of cyclin D1 in normal, metaplastic, hyperplastic endometrium and endometrioid carcinoma suggests a role in endometrial carcinogenesis.

Context: Endometrioid carcinoma is often preceded by characteristic histopathologic lesions known as endometrial hyperplasia. Estrogen appears to be involved in the development of endometrioid carcinoma. Other mechanisms of endometrial carcinogenesis include mutations in p53 and PTEN tumor suppressor genes and overexpression of cyclin D1.

Two giant basal cell carcinomas presenting simultaneously in the same patient, one resulting in lower extremity limb loss.

Giant basal cell carcinomas are a rare form of the most common malignant neoplasm of the skin. They are commonly found on the trunk and display a more aggressive behavior, resulting in local invasion and metastasis. Giant basal cell carcinomas that reach a critical size of 10 cm in diameter almost always present with metastases.

Carcinosarcoma of the parotid gland: report of a case with cytohistologic and immunohistochemical findings.

True malignant mixed tumors (carcinosarcomas) of salivary gland origin are exceedingly rare and demonstrate malignant epithelial and stromal components. We report a case of parotid gland carcinosarcoma that showed squamous cell carcinoma and malignant fibrous hystiocytoma without clinical or histologic evidence of a preexisting pleomorphic adenoma. This tumor consisted of 2 histologically different populations of cells without evidence of a common origin from the myoepithelial cell, which is the putative precursor cell of pleomorphic adenoma and its derived carcinosarcoma.