MedGen

Classic ataxia-telangiectasia (A-T) is characterized by progressive cerebellar ataxia beginning between ages one and four years, oculomotor apraxia, choreoathetosis, telangiectasias of the conjunctivae, immunodeficiency, frequent infections, and an increased risk for malignancy, particularly leukemia and lymphoma. Individuals with A-T are unusually sensitive to ionizing radiation. Non-classic forms of A-T have included adult-onset A-T and A-T with early-onset dystonia. [from GeneReviews]

A neoplasm arising from the epithelium. It may be encapsulated or non-encapsulated but non-invasive. The neoplastic epithelial cells may or may not display cellular atypia or dysplasia. In the gastrointestinal tract, when dysplasia becomes severe it is sometimes called carcinoma in situ. Representative examples are pituitary gland adenoma, follicular adenoma of the thyroid gland, and adenomas (or adenomatous polyps) of the gastrointestinal tract. [from NCI]

A benign, well circumscribed lung neoplasm morphologically characterized by the presence of cystic spaces resembling alveoli, lined by a simple cuboidal epithelium. The cystic spaces are surrounded by a spindle cell stroma which may show myxoid changes. It is a solitary, usually peripheral lung lesion. Patients are usually asymptomatic and its discovery is an incidental finding during chest X-ray examination. Surgical excision is curative. [from NCI]