ABSTRACT
Branchial carcinoid tumors are uncommon, constituting approximately 3-5% of all primary lung cancers. Classification of these tumors has evolved substantially as our understanding of the cellular, biologic, and clinical aspects of these neoplasms has improved. Initially, bronchial carcinoids were thought to be benign and therefore were classified as branchial adenomas. Currently, however, they are well recognized as having the potential for both local invasion and distant metastatic involvement. Consequently, carcinoid tumors are frankly malignant. Thus bronchial adenoma is a misnomer that should no longer be used for bronchial carcinoids. Most investigators currently favor classifying carcinoid tumors as a type of neuroendocrine neoplasm because of their potential to secrete a variety of chemical substances found in both the central nervous system and the epithelial cells of numerous organs. Bronchial carcinoids are usually characterized by a slow growth pattern and a low incidence of metastasis, and histologically confirmed by the azurophil staining and the presence of the characteristic neurosecretary granule on electron microscopy. Atypical carcinoid tumor was first defined by Arrigoni et al, who proposed the following criteria for separation of atypical carcinoid from typical carcinoid tumor: 1) increased mitotic activity with 1 mitotic figure per 1-2 high power fields (or 5-10 mitoses /10 HPF), 2) nuclear pleomorphism, hyperchromatism, and an abnormal nuclear-cytoplasmic ratio, 3) areas of increased cellularity with disorganization of the architecture, and 4) tumor necrosis. In contrast, typical carcinoid tumor may have focal cytologic pleomorphism, but necrosis is absent and mitotic figures are rare. Recently we experienced a case of atypical bronchial carcinoid with multiple distant metastasis, so we report this case with a review of the literature.
Subject(s)
Humans , Adenoma , Carcinoid Tumor , Central Nervous System , Classification , Drug Therapy , Epithelial Cells , Incidence , Lung Neoplasms , Microscopy, Electron , Mitosis , Necrosis , Neoplasm Metastasis , Research PersonnelABSTRACT
Endometriosis of the rectum is unusual condition, since it represents an invasion of previously normal bowel by hormone-dependent nonmalignant cell from uterus of the same patient. It is estimated that the incidence of endometriosis is about 8-15% of reproductive women, of whom 3-34% show intestinal invasion of rectosigmoid colon, appendix, ileum, and cecum in order of decreasing frequency. Symptoms related bowel involvement may vary from none to complete intestinal obstruction. Because the mucosa is involved infrequently there is rarely rectal bleeding. X-ray and sigmoidoscopic studies are usually negative. It was not reported that colonic endometriosis was confirmed by endoscopic biopsy. Recently we experienced a case of rectal endometriosis which presented itself as a cyclic rectal bleeding with abdominal pain and diagnosed by colonoscopic biopsy.