title: Peripheral carcinoid tumor of the lung with focal melanin production.
abstract: A case of carcinoid tumor of the lung with focal melanin production was encountered in a 56 year old Japanese woman. The tumor was found 16 years previously by mass survey chest X-ray and had enlarged two-fold in the intervening period. The tumor consisted of a variety of tumor cells showing a spindle, polygonal and pleomorphic appearance with abundant vasculature in the stroma. All tumor cells showed argyrophilia, together with a few showing argentaffinity. Melanin-containing tumor cells were also present in parts. Ultrastructurally, most tumor cells possessed various numbers of neurosecretory granules and a few of them contained granular type melanosomes. Tumor cells were connected with desmosomes and a few of them contained tonofilament-like microfilaments. Only a few contained both neurosecretory granules and melanin. By immunohistochemistry, serotonin, met-enkephalin and beta-endorphin positive cells were observed scattered throughout the tumor. A few tumor cells positive for tyrosine hydroxylase were also detected. Additionally, most tumor cells were positive for keratin. On the basis of these findings, the tumor of the current case is a pulmonary carcinoid tumor with focal melanin production.
authors.affiliation: Second Department of Pathology, Niigata University, School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fukuda
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Kamishima
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.forename: Y
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: M
authors.initials: M
authors.lastname: Naito
authors.forename: I
authors.initials: I
authors.lastname: Emura
authors.forename: T
authors.initials: T
authors.lastname: Hirono
mesh_terms: D002276:Carcinoid Tumor / Q000737:chemistry* / Q000473:pathology* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000737:chemistry* / Q000473:pathology* / Q000648:ultrastructure; D008543:Melanins / Q000032:analysis*; D008875:Middle Aged
chemical_list: D008543:Melanins