Multiple papillary adenomas of type II pneumocytes found in a 13-year-old boy with von Recklinghausen's disease.

A case of multiple papillary adenomas of type II pneumocytes is reported. A 13-year-old boy with von Recklinghausen's disease had small nodular lesions in both lungs without symptoms. The biopsied lung contained greyish-white nodules ranging in size from 0.5 to 2 mm. Light microscopic examination revealed cuboidal to low columnar cells arranged in a papillary pattern. Elastic fibres were present in the tumour stroma. Electron microscopically, the cells had osmiophilic lamellar bodies in the cytoplasm and short microvilli along the free border. The tumour cells expressed immunoreactivity for epithelial membrane antigen and surfactant apoprotein antibodies. More than 6 years after open lung biopsy, the patient is well but small nodular shadows can still be identified.