papillary adenoma(redirected from papillary adenoma of type II pneumocytes)
papillary adenomaA generic term for a usually benign tumour with cuboidal to columnar epithelial cells that typically line a fibrovascular core.
See Nipple adenoma.
See Villous adenoma.
See Gallbladder adenoma.
A common tumour, defined by the WHO as an epithelial lesion with a tubulo-papillary architecture measuring less than 0.5 cm and of low nuclear grade. Papillary adenomas occur in 7% of nephrectomies and up to 40% of autopsies, are more common in older patients, in those receiving long-term dialysis or with acquired cystic disease of the kidneys. Papillary adenomas may be associated with—or arise from—renal cell carcinomas. It is possible that loss of heterogeneity of the hOGG1 gene on 3p26.2 may signal the transition of papillary adenoma to papillary carcinoma.
Papillary adenoma is an uncommon neoplasm that presents as a solitary, well-circumscribed pulmonary nodule in asymptomatic patients. Light microscopy reveals lamellar bodies and apical cytoplasmic-dense bodies and features of Clara cells and ciliated cells. Ultrastructure (EM) studies demonstrate terminal tight junctions and microvilli. Because some of these tumours have infiltrative features, the term peripheral papillary tumour of undetermined malignant potential has been proposed.
See Aggressive digital papillary adenocarcinoma.
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An adenoma with nipple-shaped glands.
See also: adenoma
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