Small cell lung carcinoma with marked bronchial epithelial involvement.

Marked involvement of bronchial epithelium by malignant cells with a neuroendocrine immunophenotype was observed in a pulmonary lobectomy specimen containing combined small cell lung carcinoma (SCLC). Review of the medical literature reveals scant information on malignant neuroendocrine cells in bronchial epithelium accompanying SCLC and no documentation of an SCLC precursor. We discuss the possibility that the intraepithelial neoplastic lesion that we have described may be a primary lesion and possibly a precursor of SCLC and the alternative possibility that it represents invasion by underlying invasive SCLC.

Radiology-Pathology Conference: choledochal cyst.

We report the radiologic and pathologic findings of a newborn with a choledochal cyst and review the etiology, diagnostic considerations, and management of this entity.

Quadrivalvular marantic endocarditis (ME) mimicking acute bacterial endocarditis (ABE).

Marantic endocarditis (ME) is defined by noninfectious valvular vegetations. The most common disorders associated with ME are malignancy with or without hypercoagulable state, intercardiac instrumentation, residual vegetations from previously treated infective endocarditis (IE), renal insufficiency, and burns. Another important cause of ME is systemic lupus erythematosus when accompanied by vegetations, that is, Libman-Sacks endocarditis.