Pulmonary alveolar proteinosis mimicking idiopathic pulmonary fibrosis.

Pulmonary alveolar proteinosis (PAP) is a rare disorder of unknown etiology. While most biopsies from patients with PAP disclose a prominent positive periodic acid-Schiff, diastase-resistant intra-alveolar exudate, and minimal interstitial thickening, interstitial fibrosis and honeycombing can be the predominant histologic findings. We recently identified two patients with PAP who initially were thought to have idiopathic pulmonary fibrosis, but whose biopsies ultimately disclosed PAP with considerable interstitial fibrosis.

Tuberous sclerosis-associated lesions of the kidney, brain, and skin are angiogenic neoplasms.

Background: Tuberous sclerosis is an autosomal dominant condition characterized by the development of benign neoplasms of the brain, kidney, and skin. Progressive growth and malignant transformation of brain and kidney lesions constitute the major cause of morbidity and mortality in adults with tuberous sclerosis. In addition, growth of skin lesions may be disfiguring to patients.