title: Leu-M1 immunoreactivity and phaeochromocytoma.
abstract: The aim was to evaluate Leu-M1 immunoreactivity as a prognostic factor in phaeochromocytoma. Anti-Leu-M1 monoclonal antibodies were used to determine the Leu-M1 immunoreactivity in 17 histologically confirmed phaeochromocytomas from 15 patients, using an avidin-biotin technique. Ten patients had a sporadic phaeochromocytoma, and five had multiple endocrine neoplasia type 2A (MEN 2A). Malignancy was diagnosed in three patients by the presence of metastases. Leu-M1 immunoreactivity was shown in 12 (70.5%) phaeochromocytomas. Three patterns of arrangement were observed: isolated (scattered positive cells) (n = 3); focal (aggregates of positive cells) (n = 5), and diffuse patterns (dispersed positive cells) (n = 4). Two cases of malignant phaeochromocytoma were positive (one focal and one isolated pattern). All cases of MEN 2A showed immunoreactivity, although no characteristic pattern was prevalent. A diffuse pattern was observed in all phaeochromocytomas longer than 7 cm. In conclusion, Leu-M1 expression is frequent in phaeochromocytoma. However, Leu-M1 immunoreactivity seems to be useless in predicting malignant behaviour and to be influenced mainly by tumour size.
authors.affiliation: Department of Endocrinology, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Masmiquel
authors.forename: M
authors.initials: M
authors.lastname: Castro-Forns
authors.forename: I
authors.initials: I
authors.lastname: de Torres
authors.forename: A
authors.initials: A
authors.lastname: García
authors.forename: M T
authors.initials: MT
authors.lastname: Vidal
authors.forename: R
authors.initials: R
authors.lastname: Simó
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000150:complications / Q000378:metabolism*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016256:Lewis X Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018813:Multiple Endocrine Neoplasia Type 2a / Q000150:complications / Q000378:metabolism; D010673:Pheochromocytoma / Q000150:complications / Q000378:metabolism*; D011379:Prognosis
chemical_list: D016256:Lewis X Antigen