general pathological features of typical carcinoid: typical carcinoid is divided into central (hilar type) and peripheral type. Peripheral than central common, accounting for atypical carcinoid of the 2 / 3 or more. In leaves and segmental bronchi. Generally divided into two types: a. polypoid: tumor located in the bronchial lumen, or spherical mass was polypoid, suddenly into the lumen, the surface smooth, light red; b. mucosal infiltration type: Weng film showed the lesion was uplifted plaque, the main tumor penetrating the bronchial wall shaped like an iceberg, the peak to the surrounding lung tissue penetration.
Peripheral about 1 / 3, the tumor is located in the small bronchi and bronchioles. Tumors were nodular or lobulated, no capsule, slightly harder texture, cut gray with yellow, and the surrounding lung tissue boundaries more clear. Tumors tend to spread along the airways into the formation of multiple tumor nodules or diffuse infiltration.
microscopic pathologic features of typical carcinoid: tumor cells arranged in organs like, cord-like, island, fence-like, the Department of ribbon, or colored ribbon and rosettes like arrangement. In addition to the typical structure, the part of the typical carcinoid can be expressed as papillary, sclerosing, follicular and glandular structures. For the capillary network around the cancer nests. Uniform cells, and a moderate amount of slightly eosinophilic granular cytoplasm; nuclear round, oval or short spindle, the same size and shape, dust-like nuclear chromatin, nuclear membrane is not thick, no nucleolus or not obvious. A small number of nuclear fission, but a typical carcinoid tumor mitotic counts. Carcinoma without necrosis, or occasionally a small point-like necrosis.
In a typical carcinoid tissue, there may be focal cancer cell nest or spindle-shaped cells rich in cytoplasm with eosinophilic granules, deeply stained nucleus is relatively small, similar to the thyroid gland schuette ear cells (Hiirtvhvles cell). Cytoplasm of a minority class of cells clear, as clear cell carcinoid tumor.
Pathological features of typical carcinoid, and some classes can produce mucous cells, tumor cells showed the cytoplasm of signet ring-like or contain melanin, the brain showed a return to the nuclear shape.
Carcinoid tumors are usually less matrix, mainly rich in blood vessels around the cancer nests, but some cancer, bone and cartilage matrix appear metaplasia, with dense fibrosis and calcification. Amyloid deposition in the tumor stroma are not uncommon.
Peripheral carcinoid tumors, bronchial mucosa can be seen near the small neuroendocrine cell hyperplasia or with airway fibrosis. Airway rare diffuse idiopathic neuroendocrine cell hyperplasia may be associated with multiple micro-aneurysms (tumorlet) and multiple carcinoid tumors.