At present, an important part of prognostic information, together with particular treatment strategies in breast cancer, take into account the immunohistochemical phenotype of the primary tumor location. However, the changing heterogeneity intrinsic to neoplastic cells in general leads us to consider the possibility that the expression of these proteins is modified during tumoral development and dissemination. With this hypothesis as a starting point, 60 patients with breast cancer were studied with immunohistochemistry, the expression of estrogen and progestagenic receptors, proliferation through the Ki-67 expression, and the overexpression of HER-2 and p53 in both the primary location and the lymph node metastases. If we consider significant change to be loss (from positive to negative) or gain (negative to positive) of expression in some of the studied determinations, we find that this is produced in 60% of the tumors studied. These results demonstrate the modification of immunohistochemical expression of the proteins studied between the primary tumor location and the lymph node metastases.
The differential diagnosis of Cushing's syndrome is a major challenge to clinical endocrinologists, especially those infrequent cases referred to as occult ectopic ACTH syndromes. Although bronchial carcinoids are well known to be a cause of Cushing's syndrome due to ectopic ACTH secretion, very few cases of carcinoid tumourlets causing an ACTH ectopic syndrome have been reported, and their origin remains controversial. For some authors, tumourlets and typical carcinoids represent distinct pathological entities, whilst others hold that tumourlets are merely microscopic carcinoid tumours. We report a patient with an aggressive Cushing's syndrome that required bilateral adrenalectomy, diagnosed 22 years before a 3-cm lung nodule became apparent on routine chest X-ray. The biopsy after lung surgery revealed a typical peripheral bronchial carcinoid surrounded by tumourlets. Both tumourlets and carcinoid tumour showed strongly positive ACTH immunostaining. Recently, Arioglu et al. (1998) reported a case of Cushing's syndrome caused by pulmonary carcinoid tumourlets, concluding that this entity should be considered in the differential diagnosis of occult ectopic ACTH syndrome. Furthermore, we consider that the carcinoid tumourlets found in our patient, were the initial source of ACTH, leading to Cushing's syndrome with a rapid onset, and that a loss of cell proliferation control in one of such tumourlets many years later, could have resulted in the development of a typical carcinoid tumour, reinforcing the theory of a common origin of these lesions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.