Dimorphic variant of ductal carcinoma in situ of the breast

We report a case of dimorphic variant of ductal carcinoma in situ (dimorphic DCIS), composed of an epithelium intermixed with columnar cells and dimorphic cells. The findings of typical DCIS architecture support categorization as DCIS on a low-power view. Furthermore, there was no difference in the nuclear morphology of the two cell types on the high-power view. The two cell types comprising dimorphic DCIS were negative for p63, CK 5/6 and 14. On the contrary, both cell types were diffusely positive for nuclear ER and AR, as well as marked membrane-associated staining for E-cadherin and cytoplasmic staining for GCDFP-15. These immunohistochemical marker results are similar to conventional DCIS and there were no differences in expression patterns between the columnar epithelial cells and dimorphic cells. The morphological features of dimorphic cells may be confused with cells of other origins if the features of dimorphic DCIS are not recognized. Careful observation of morphological architecture and expression of immunohistochemical markers may support diagnosis. Keywords: Dimorphic cell, Ductal carcinoma in situ, Breast carcinom

Microtubule Organization and Microtubule-Associated Proteins (MAPs)

Dendrites have a unique microtubule organization. In vertebrates, dendritic microtubules are organized in antiparallel bundles, oriented with their plus ends either pointing away or toward the soma. The mixed microtubule arrays control intracellular trafficking and local signaling pathways, and are essential for dendrite development and function. The organization of microtubule arrays largely depends on the combined function of different microtubule regulatory factors or generally named microtubule-associated proteins (MAPs). Classical MAPs, also called structural MAPs, were identified more than 20 years ago based on their ability to bind to and copurify with microtubules. Most classical MAPs bind along the microtubule lattice and regulate microtubule polymerization, bundling, and stabilization. Recent evidences suggest that classical MAPs also guide motor protein transport, interact with the actin cytoskeleton, and act in various neuronal signaling networks. Here, we give an overview of microtubule organization in dendrites and the role of classical MAPs in dendrite development, dendritic spine formation, and synaptic plasticity