[Immunohistochemical study of 4 cases of mucoid and argyrophilic carcinoma of the breast].

Three to 5% of breast carcinomas are argyrophilic, including some which are mucinous and thus "composite", whereas there are no argyrophilic cells in normal breast nor in benign breast pathology. This raises the problem of the origin and type of these argyrophilic cells. We carried out a histologic and immunohistochemical study in 4 such cases of mucoid tumors containing at least 50% argyrophilic cells. Two of these tumors presenting node involvement were also studied immunohistochemically. The histologic study showed colloid and intragalactophoric proliferation areas in cell cases and some endocrine areas in 2 out of 4 cases. Argyrophilic cells were present in all of these areas. True mucoargyrophilic amphicrine cells were found primarily in colloid areas. None of these tumors were argentaffin. Immunohistochemical study was performed by the PAP method using antibody directed against VIP, ACTH, PP, somatostatin, bombesin, calcitonin, gastrin, prolactin and GH. Three out of four tumors were positive with VIP. Moreover one of them contained ACTH cells and a metastasis of this tumor contained bombesin cells. No tumor was positive with the other anti-sera tested. This study is related to the rare series in the literature which report secretion of ACTH, catecholamins, bombesin, gastrin, VIP, PP, somatostatin, prolactin, etc. The number of cases reported to date remains too low to show a significant prognostic difference between amphicrine tumors and other mammary carcinomas.