atypical adenomatous hyperplasia

Also found in: Acronyms.

atypical adenomatous hyperplasia

Pathology lung
A term of art for what is essentially dysplassia of type-II cells in the lungs, which corresponds to a small but prominent focus of plump cells lining the air spaces. AAH is often an incidental finding in lungs resected for carcinoma, characterised by firm, 1–5-mm diameter white nodules surrounded by a polygon of interstitial fibrosis—hyperchromatic enlarged cuboidal eosinophilic pneumocytes which are neither papillary nor desquamate, sharply demarcated from surrounding lung. Some develop into bronchoalveolar carcinoma, a relatively indolent malignancy and essentially a carcinoma in situ of the lungs.

Pathology prostate
A localised proliferation of small (prostate) acini, which mimics prostate carcinoma, usually lacks cytological atypia, and has basal cells at the transition zone of the prostate. It is distinguished from well-differentiated CA by a relative lack of nuclear or nucleolar enlargement, infrequent crystalloids and a fragmented, but partially intact, basement membrane. AAH is more common in older patients with larger prostates, greater degree of nodular hyperplasia, more cancer and, if malignant, with higher Gleason scores.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

Atypical adenomatous hyperplasia

The over-growth of the endometrium. This precancerous condition is estimated to progress to cancer in one third of the cases.
Mentioned in: Endometrial Cancer
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Hyal-3 staining intensity in epithelial cells was weak in atypical adenomatous hyperplasia, moderate in basal cell hyperplasia and strong in moderate hyperplasia (Figure 3B).
Hyaluronidase (Hyal)-1 and -3 in basal cell hyperplasia, squamous metaplasia, moderate dysplasia, atypical adenomatous hyperplasia, severe dysplasia, squamous cell carcinoma and adenocarcinoma, as shown by immunohistochemistry staining.
Atypical adenomatous hyperplasia of the lung: a clinicopathological study of 118 cases including cases with multiple atypical adenomatous hyperplasia.
Clonal growth of atypical adenomatous hyperplasia of the lung: cytofluorometric analysis of nuclear DNA content.
Ground-glass opacities on thin-section helical CT: differentiation between bronchioloalveolar carcinoma and atypical adenomatous hyperplasia. AJR Am J Roentgenol.
Atypical adenomatous hyperplasia ofthelung: a clinicopathological study of 118 cases including cases with multiple atypical adenomatous hyperplasia.
Atypical adenomatous hyperplasia consists of peripheral lesions, found in centriacinar regions close to terminal and respiratory bronchioles, that arise from bronchioloalveolar epithelium.
(8) However, in recent years acidic mucin has been demonstrated by histochemistry in a high proportion of atypical adenomatous hyperplasia (54%-63%) (33,34) and in sclerosing adenosis, basal cell hyperplasia, and mucinous metaplasia of benign prostatic glands.
Mucin expression in atypical adenomatous hyperplasia of the prostate.
Association ofVerumontanum Mucosal Gland Hyperplasia (VMGH) With Atypical Adenomatous Hyperplasia (AAH) in Radical Prostatectomy Specimens(*) VMGH Present VMGH Absent Total AAH present 21 16 37 AAH absent 11 62 73 Total 32 78 110
Atypical adenomatous hyperplasia is a lobular, relatively well-circumscribed, but sometimes focally infiltrative lesion consisting of closely packed, small acini with pale to clear cytoplasm and frequent intraluminal crystalloids and, less commonly, pale blue mucin.[3-5] It is a lesion almost exclusively of transition zone origin and has overlapping morphologic features with well-differentiated prostate cancer of transition zone origin.
(*) TURP indicates transurethral resection of the prostate; BPH, benign prostatic hyperplasia; CA, adenocarcinoma; PCA, prostatic adenocarinoma AAH, atypical adenomatous hyperplasia; PIN, prostatic intraepithelial neoplasia; and NA, not available because TURP was not performed.