ABSTRACT
The authors present a rare case of a patient with an estrogen receptor (ER) positive malignant colorectal stricture, with no identifiable primary breast carcinoma. There was demonstrated endoscopic and symptomatic improvement after treatment with letrozole. Gastrointestinal metastases from breast cancer usually present with a previous history of breast cancer, however our patient had no prior or current proven history of breast cancer. Biopsy and immunohistochemical staining of the malignant colonic lesion showed an adenocarcinoma with positive ER staining. Mammogram, breast ultrasound and MRI of the breasts were all negative. She was successfully treated with letrozole for 3 years that resulted in endoscopic and symptomatic improvement in her colorectal stricture.
Subject(s)
Adenocarcinoma/drug therapy , Adenocarcinoma/pathology , Antineoplastic Agents/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Nitriles/therapeutic use , Receptors, Estrogen/analysis , Triazoles/therapeutic use , Adenocarcinoma/complications , Aged , Colorectal Neoplasms/complications , Constriction, Pathologic/drug therapy , Constriction, Pathologic/etiology , Female , Humans , LetrozoleABSTRACT
Development of the vertebrate eye is dependent on multiple tissue interactions and distinct sets of transcription factors and signalling molecules. The latter are thought to be FGF8 and BMP4, proteins secreted from the neural plate to induce lens formation in the overlying ectoderm. Here we show that the Pbx transcription factor plays a crucial role in this process, as it is required for FGF8 expression in the neural plate and is thus part of the complex hierarchy of genes involved in lens induction.
