CD34, CD117, and Ki-67 expression in phyllodes tumor of the breast: an immunohistochemical study of 33 cases.

Phyllodes tumors (PTs) of the breast are biphasic lesions, comprising an epithelial component set within a neoplastic spindle-celled stroma. These tumors have been classified as benign, borderline, and malignant based on a combination of histological criteria, including stromal cellularity, nuclear pleomorphism, mitotic rate, stromal overgrowth, and margin appearance. The aim of this study was to evaluate the expression of CD34, CD117 (c-kit), and Ki-67 in PT of the breast and attempt to correlate the staining pattern with tumor grade by morphology.

Adrenal myelolipomas show nonrandom X-chromosome inactivation in hematopoietic elements and fat: support for a clonal origin of myelolipomas.

Myelolipomas are defined as mature fat associated with hematopoietic elements, often found in the adrenal gland. The question of whether the hematopoietic cells are truly "normal" has not been evaluated extensively. In this study, we evaluated histologic, immunohistochemical features and comparisons of X-chromosome inactivation patterns in 19 myelolipomas.

Immunophenotypic overlap between adenoid cystic carcinoma and collagenous spherulosis of the breast: potential diagnostic pitfalls using myoepithelial markers.

Adenoid cystic carcinoma of the breast is a rare neoplasm whose cribriform architecture may mimic invasive cribriform carcinoma, cribriform ductal carcinoma in situ, and collagenous spherulosis. The diagnosis may be even more challenging in needle core biopsies. Immunohistochemical expression of p63 and c-kit distinguishes adenoid cystic carcinoma from invasive cribriform carcinoma and ductal carcinoma in situ.